Hello dear friends! Today we will look at the assembly of an amplifier based on the TDA7386 chip. This microcircuit is a four-channel low-frequency amplifier of class AB, with a maximum output power of 45W per channel, into a 4-ohm load.
The TDA7386 is designed to increase the power of car radios, car radios, and can be used as a home amplifier, as well as for holding any indoor parties or outdoor events.
The amplifier circuit on the TDA7386, in my opinion, is the simplest; any beginner can assemble it, either by surface mounting or on a printed circuit board. Another wonderful advantage of an amplifier assembled according to this circuit is its very small dimensions.
The TDA7386 chip has protection against short circuits on the output channels and protection against overheating of the crystal.
You can download the datasheet for this chip at the very bottom of the article.
Main characteristics of TDA7386:
- Supply voltage from 6 to 18 Volts
- Peak output current 4.5-5A
- Output power at 4 Ohm 10% THD 24W
- Output power at 4 Ohm 0.8% THD 18W
- Maximum output power at 4 Ohm load 45 W
- Gain 26dB
- Load resistance not less than 4 Ohm
- Crystal temperature 150 degrees Celsius
- Reproducible frequency range 20-20000 Hz.
The amplifier can be assembled according to two schemes, the first:
Component ratings:
C1, C2, C3, C4, C8 – 0.1 µF
C5 – 0.47 µF
C6 – 47uF 25V
C7 – 2200uF and more than 25V
C9, C10 – 1 µF
R1 – 10kOhm 0.25W
R2 – 47kOhm 0.25W.
Component ratings:
C1, C6, C7, C8, C9, C10 – 0.1 µF
C2, C3, C4, C5 – 470pF
C11 - 2200uF and more than 25V
C12, C13, C14 – 0.47 µF
C15 – 47uF 25V
R1,R2,R3,R4 – 1kOhm 0.25W
R5 – 10kOhm 0.25W
R6 – 47kOhm 0.25W.
The only difference is in the wiring of the microcircuit, but the principle does not change.
We will assemble according to the first scheme, if anyone is interested in the second scheme, you can read the article: “”, the second scheme and the printed circuit board for it are analyzed in detail. The TDA7386 and TDA7560 microcircuits are identical in pinout and interchangeable. One main difference is that the TDA7560 is designed for a 2 Ohm load, unlike the TDA7386, the rest of the parameters and characteristics are similar.
You can download the printed circuit board below the article.
The radiator must be installed at least 400 square centimeters. In the photo below, you can see the TDA7386 amplifier I assembled with a radiator with an area of less than 200 square centimeters. I tested this amplifier for several hours, the load included two 30W speakers with a load of 8 Ohms each, at an average volume level, the microcircuit got very hot, but no problems were noticed. This was a test, I advise you friends to install a radiator of at least 400 square centimeters or use the amplifier case as a radiator if it is aluminum or duralumin.
The radiator must be cleaned with fine sandpaper at the point of contact with the microcircuit; if it is painted, this will increase thermal conductivity. Next, place it on a heat-conducting paste, such as KPT-8.
Details.
The capacitors can be ceramic, you won’t hear the difference if you install film. Resistors with a power of 0.25 W.
A little about the ST-BY and MUTE modes on the TDA7386 chip (pin 4 and pin 22).
The ST-BY mode on the TDA7386, as well as on its brothers (TDA7560, TDA7388), is controlled as follows; if you want your amplifier to be constantly in the “On” mode, then you need to connect the outermost terminal of the resistor R1 to + 12V and leave it in this position, that is, solder a jumper. If the jumper is removed (the outermost terminal of resistor R1 is left in the air), then the microcircuit is in standby mode; in order for the amplifier to start singing, you need to briefly connect the outermost terminal of resistor R1 to +12V. In order to put the amplifier back into standby mode, it is necessary to briefly connect the extreme terminal of resistor R1 to the common negative (GND).
The MUTE mode on the TDA7386 is controlled in a similar way. In order for the amplifier to be constantly in the “Sound on” mode, it is necessary to connect the outermost terminal of resistor R2 to +12V. If you want the amplifier to operate in the “Silent” mode, then you need to connect the outermost terminal of resistor R2 and hold it with a common negative (GND).
I assembled several amplifiers on TDA7560, TDA7386, TDA7388, I noticed one thing, if you leave R1 and R2 in the air, while using only one input out of four, then when power is applied to the board, the amplifier is in standby mode, all of the above operations are with ST modes -BY and MUTE work fine. If you use all the inputs, then when power is supplied to the board, the amplifier itself begins to sing, although power is not supplied to legs 4 and 22. However, experiment!
Updated: 04/27/2016
An excellent amplifier for home can be assembled using the TDA7294 chip. If you are not strong in electronics, then such an amplifier is an ideal option; it does not require fine tuning and debugging like a transistor amplifier and is easy to build, unlike a tube amplifier.
The TDA7294 microcircuit has been in production for 20 years and has still not lost its relevance and is still in demand among radio amateurs. For a novice radio amateur, this article will be a good help in getting to know integrated audio amplifiers.
In this article I will try to describe in detail the design of the amplifier on the TDA7294. I will focus on a stereo amplifier assembled according to the usual circuit (1 microcircuit per channel) and will briefly talk about the bridge circuit (2 microcircuits per channel).
TDA7294 chip and its features
TDA7294 is the brainchild of SGS-THOMSON Microelectronics, this chip is an AB class low-frequency amplifier, and is built on field-effect transistors.
The advantages of the TDA7294 include the following:
- output power, with distortion 0.3–0.8%:
- 70 W for 4 ohm load, conventional circuit;
- 120 W for 8 ohm load, bridge circuit;
- Mute function and Stand-By function;
- low noise level, low distortion, frequency range 20–20000 Hz, wide operating voltage range - ±10–40 V.
Specifications
| Technical characteristics of the TDA7294 chip | |||||
|---|---|---|---|---|---|
| Parameter | Conditions | Minimum | Typical | Maximum | Units |
| Supply voltage | ±10 | ±40 | IN | ||
| Frequency range | Signal 3 db Output power 1W |
20-20000 | Hz | ||
| Long-term output power (RMS) | harmonic coefficient 0.5%: Up = ±35 V, Rн = 8 Ohm Up = ±31 V, Rн = 6 Ohm Up = ±27 V, Rн = 4 Ohm |
60 60 60 |
70 70 70 |
W | |
| Peak music output power (RMS), duration 1 sec. | harmonic factor 10%: Up = ±38 V, Rн = 8 Ohm Up = ±33 V, Rн = 6 Ohm Up = ±29 V, Rн = 4 Ohm |
100 100 100 |
W | ||
| Total harmonic distortion | Po = 5W; 1kHz Po = 0.1–50W; 20–20000Hz |
0,005 | 0,1 | % | |
| Up = ±27 V, Rн = 4 Ohm: Po = 5W; 1kHz Po = 0.1–50W; 20–20000Hz |
0,01 | 0,1 | % | ||
| Protection response temperature | 145 | °C | |||
| Quiescent current | 20 | 30 | 60 | mA | |
| Input impedance | 100 | kOhm | |||
| Voltage Gain | 24 | 30 | 40 | dB | |
| Peak output current | 10 | A | |||
| Operating temperature range | 0 | 70 | °C | ||
| Case thermal resistance | 1,5 | °C/W | |||
Pin assignment
| Pin assignment of the TDA7294 chip | |||
|---|---|---|---|
| IC output | Designation | Purpose | Connection |
| 1 | Stby-GND | "Signal Ground" | "General" |
| 2 | In- | Inverting input | Feedback |
| 3 | In+ | Non-inverting input | Audio input via coupling capacitor |
| 4 | In+Mute | "Signal Ground" | "General" |
| 5 | N.C. | Not used | – |
| 6 | Bootstrap | "Voltage boost" | Capacitor |
| 7 | +Vs | Input stage power supply (+) | |
| 8 | -Vs | Input stage power supply (-) | |
| 9 | Stby | Standby mode | Control block |
| 10 | Mute | Mute mode | |
| 11 | N.C. | Not used | – |
| 12 | N.C. | Not used | – |
| 13 | +PwVs | Output stage power supply (+) | Positive terminal (+) of the power supply |
| 14 | Out | Exit | Audio output |
| 15 | -PwVs | Output stage power supply (-) | Negative terminal (-) of the power supply |
Note. The microcircuit body is connected to the power supply negative (pins 8 and 15). Do not forget about insulating the radiator from the amplifier body or insulating the microcircuit from the radiator by installing it through a thermal pad.
I would also like to note that in my circuit (as well as in the datasheet) there is no separation of input and output lands. Therefore, in the description and in the diagram, the definitions of “general”, “ground”, “housing”, GND should be perceived as concepts of the same sense.
The difference is in the cases
The TDA7294 chip is available in two types - V (vertical) and HS (horizontal). The TDA7294V, having a classic vertical body design, was the first to roll off the production line and is still the most common and affordable.
Complex of protections
The TDA7294 chip has a number of protections:
- protection against power surges;
- protection of the output stage from short circuit or overload;
- thermal protection. When the microcircuit heats up to 145 °C, the mute mode is activated, and at 150 °C the standby mode is activated;
- protection of microcircuit pins from electrostatic discharges.
Power amplifier on TDA7294
A minimum of parts in the harness, a simple printed circuit board, patience and known good parts will allow you to easily assemble an inexpensive TDA7294 UMZCH with clear sound and good power for home use.
You can connect this amplifier directly to the line output of your computer sound card, because The nominal input voltage of the amplifier is 700 mV. And the nominal voltage level of the linear output of the sound card is regulated within 0.7–2 V.
Amplifier block diagram
The diagram shows a version of a stereo amplifier. The structure of the amplifier using a bridge circuit is similar - there are also two boards with TDA7294.
- A0. power unit
- A1. Control unit for Mute and Stand-By modes
- A2. UMZCH (left channel)
- A3. UMZCH (right channel)
Pay attention to the connection of the blocks. Improper wiring inside the amplifier may cause additional interference. To minimize noise as much as possible, follow several rules:
- Power must be supplied to each amplifier board using a separate harness.
- The power wires must be twisted into a braid (harness). This will compensate for the magnetic fields created by the current flowing through the conductors. We take three wires (“+”, “-”, “Common”) and weave them into a pigtail with a slight tension.
- Avoid ground loops. This is a situation where a common conductor, connecting blocks, forms a closed circuit (loop). The connection of the common wire must go in series from the input connectors to the volume control, from it to the UMZCH board and then to the output connectors. It is advisable to use connectors isolated from the housing. And for input circuits there are also shielded and insulated wires.
List of parts for TDA7294 power supply:
When purchasing a transformer, please note that the effective voltage value is written on it - U D, and by measuring it with a voltmeter you will also see the effective value. At the output after the rectifier bridge, the capacitors are charged to the amplitude voltage - U A. The amplitude and effective voltages are related by the following relationship:
U A = 1.41 × U D
According to the characteristics of the TDA7294, for a load with a resistance of 4 Ohms, the optimal supply voltage is ±27 volts (U A). The output power at this voltage will be 70 W. This is the optimal power for the TDA7294 - the distortion level will be 0.3–0.8%. There is no point in increasing the power supply to increase power because... the level of distortion increases like an avalanche (see graph).
We calculate the required voltage of each secondary winding of the transformer:
U D = 27 ÷ 1.41 ≈ 19 V
I have a transformer with two secondary windings, with a voltage of 20 volts on each winding. Therefore, in the diagram I designated the power terminals as ± 28 V.
To obtain 70 W per channel, taking into account the efficiency of the microcircuit of 66%, we calculate the power of the transformer:
P = 70 ÷ 0.66 ≈ 106 VA
Accordingly, for two TDA7294 this is 212 VA. The nearest standard transformer, with a margin, will be 250 VA.
It is appropriate to state here that the power of the transformer is calculated for a pure sinusoidal signal; corrections are possible for a real musical sound. So, Igor Rogov claims that for a 50 W amplifier, a 60 VA transformer will be sufficient.
The high-voltage part of the power supply (before the transformer) is assembled on a 35x20 mm printed circuit board; it can also be mounted:
The low-voltage part (A0 according to the structural diagram) is assembled on a 115x45 mm printed circuit board:
All amplifier boards are available in one.
This power supply for the TDA7294 is designed for two chips. For a larger number of microcircuits, you will have to replace the diode bridge and increase the capacitor capacity, which will entail a change in the dimensions of the board.
Control unit for Mute and Stand-By modes
The TDA7294 chip has a Stand-By mode and a Mute mode. These functions are controlled through pins 9 and 10, respectively. The modes will be enabled as long as there is no voltage on these pins or it is less than +1.5 V. To “wake up” the microcircuit, it is enough to apply a voltage greater than +3.5 V to pins 9 and 10.
To simultaneously control all UMZCH boards (especially important for bridge circuits) and save radio components, there is a reason to assemble a separate control unit (A1 according to the block diagram):
Parts list for control box:
- Diode (VD1). 1N4001 or similar.
- Capacitors (C1, C2). Polar electrolytic, domestic K50-35 or imported, 47 uF 25 V.
- Resistors (R1–R4). Ordinary low-power ones.
The printed circuit board of the block has dimensions of 35×32 mm:
The control unit's task is to ensure silent switching on and off of the amplifier using the Stand-By and Mute modes.
The operating principle is as follows. When the amplifier is turned on, along with the capacitors of the power supply, capacitor C2 of the control unit is also charged. Once it is charged, Stand-By mode will turn off. It takes a little longer for capacitor C1 to charge, so Mute mode will turn off second.
When the amplifier is disconnected from the network, capacitor C1 discharges first through diode VD1 and turns on the Mute mode. Then capacitor C2 discharges and sets the Stand-By mode. The microcircuit becomes silent when the power supply capacitors have a charge of about 12 volts, so no clicks or other sounds are heard.
Amplifier based on TDA7294 according to the usual circuit
The microcircuit's connection circuit is non-inverting, the concept corresponds to the original one from the datasheet, only the component values have been changed to improve the sound characteristics.
Parts List:
- Capacitors:
- C1. Film, 0.33–1 µF.
- C2, C3. Electrolytic, 100-470 µF 50 V.
- C4, C5. Film, 0.68 µF 63 V.
- C6, C7. Electrolytic, 1000 µF 50 V.
- Resistors:
- R1. Variable dual with linear characteristic.
- R2–R4. Ordinary low-power ones.
Resistor R1 is double because stereo amplifier. Resistance of no more than 50 kOhm with a linear rather than logarithmic characteristic for smooth volume control.
Circuit R2C1 is a high-pass filter (HPF) that suppresses frequencies below 7 Hz without passing them to the amplifier input. Resistors R2 and R4 must be equal to ensure stable operation of the amplifier.
Resistors R3 and R4 organize a negative feedback circuit (NFC) and set the gain:
Ku = R4 ÷ R3 = 22 ÷ 0.68 ≈ 32 dB
According to the datasheet, the gain should be in the range of 24–40 dB. If it is less, the microcircuit will self-excite; if it is more, distortion will increase.
Capacitor C2 is involved in the OOS circuit; it is better to take one with a larger capacitance to reduce its effect on low frequencies. Capacitor C3 provides an increase in the supply voltage of the output stages of the microcircuit - “voltage boost”. Capacitors C4, C5 eliminate noise introduced by wires, and C6, C7 supplement the filter capacity of the power supply. All amplifier capacitors, except C1, must have a voltage reserve, so we take 50 V.
The amplifier's printed circuit board is single-sided, quite compact - 55x70 mm. When developing it, the goal was to separate the “ground” with a star, ensure versatility and at the same time maintain minimal dimensions. I think this is one of the smallest boards for TDA7294. This board is designed for installation of one microcircuit. For the stereo option, accordingly, you will need two boards. They can be installed side by side or one above the other like mine. I’ll tell you more about versatility a little later.
The radiator, as you can see, is indicated on one board, and the second, similar one, is attached to it from above. Photos will be a little further.
Amplifier based on TDA7294 using a bridge circuit
A bridge circuit is a pairing of two conventional amplifiers with some adjustments. This circuit solution is designed for connecting acoustics with a resistance of not 4, but 8 ohms! Acoustics are connected between the amplifier outputs.
There are only two differences from the usual scheme:
- the input capacitor C1 of the second amplifier is connected to ground;
- added feedback resistor (R5).
The printed circuit board is also a combination of amplifiers according to the usual circuit. Board size – 110×70 mm.
Universal board for TDA7294
As you have already noticed, the above boards are essentially the same. The following version of the printed circuit board fully confirms the versatility. On this board you can assemble a 2x70 W stereo amplifier (regular circuit) or a 1x120 W mono amplifier (bridged). Board size – 110×70 mm.
Note. To use this board in a bridge version, you need to install resistor R5 and install jumper S1 in a horizontal position. In the figure, these elements are shown as dotted lines.
For a conventional circuit, resistor R5 is not needed, and the jumper must be installed in a vertical position.
Assembly and adjustment
Assembling the amplifier will not pose any particular difficulties. The amplifier does not require any adjustment as such and will work immediately, provided that everything is assembled correctly and the microcircuit is not defective.
Before first use:
- Make sure the radio components are installed correctly.
- Check that the power wires are connected correctly, do not forget that on my amplifier board the ground is not centered between plus and minus, but on the edge.
- Make sure that the microcircuits are isolated from the radiator; if not, then check that the radiator is not in contact with ground.
- Apply power to each amplifier in turn, so there is a chance you won’t burn out all the TDA7294 at once.
First start:
- We do not connect the load (acoustics).
- We connect the amplifier inputs to ground (connect X1 with X2 on the amplifier board).
- We serve food. If everything is fine with the fuses in the power supply and nothing smokes, then the launch was a success.
- Using a multimeter, we check the absence of direct and alternating voltage at the output of the amplifier. A slight constant voltage is allowed, no more than ±0.05 volts.
- Turn off the power and check the chip body for heating. Be careful, the capacitors in the power supply take a long time to discharge.
- We send a sound signal through a variable resistor (R1 according to the diagram). Turn on the amplifier. The sound should appear with a slight delay, and disappear immediately when turned off; this characterizes the operation of the control unit (A1).
Conclusion
I hope this article will help you build a high-quality amplifier using the TDA7294. Finally, I present a few photos of the assembly process, do not pay attention to the quality of the board, the old PCB is unevenly etched. Based on the assembly results, some edits were made, so the boards in the .lay file are slightly different from the boards in the photographs.
The amplifier was made for a good friend, he came up with and implemented such an original housing. Photos of the assembled stereo amplifier on the TDA7294:
On a note: All printed circuit boards are collected in one file. To switch between “signatures”, click on the tabs as shown in the figure.
list of files
A low frequency amplifier (LFA) is a device for amplifying electrical oscillations corresponding to the frequency range audible to the human ear, i.e. the LFA should amplify in the frequency range from 20 Hz to 20 kHz, but some VLFs can have a range of up to 200 kHz. The ULF can be assembled as a separate device, or used in more complex devices - televisions, radios, radios, etc.
The peculiarity of this circuit is that pin 11 of the TDA1552 microcircuit controls the operating modes - Normal or MUTE.
C1, C2 - pass-through blocking capacitors, used to cut off the constant component of the sinusoidal signal. It is better not to use electrolytic capacitors. It is advisable to place the TDA1552 chip on a radiator using heat-conducting paste.
In principle, the presented circuits are bridge ones, because in one housing of the TDA1558Q microassembly there are 4 amplification channels, so pins 1 - 2, and 16 - 17 are connected in pairs, and they receive input signals from both channels through capacitors C1 and C2. But if you need an amplifier for four speakers, then you can use the circuit option below, although the power will be 2 times less per channel.
The basis of the design is the TDA1560Q class H microassembly. The maximum power of this ULF reaches 40 W, with a load of 8 ohms. This power is provided by approximately twice the increased voltage due to the operation of the capacitors.
The output power of the amplifier in the first circuit assembled on the TDA2030 is 60W at a load of 4 Ohms and 80W at a load of 2 Ohms; TDA2030A 80W at 4 ohm load and 120W at 2 ohm load. The second circuit of the considered ULF is already with an output power of 14 Watts.
This is a typical two-channel ULF. With a little wiring of passive radio components, this chip can be used to build an excellent stereo amplifier with an output power of 1 W on each channel.
The TDA7265 microassembly is a fairly powerful two-channel Hi-Fi class AB amplifier in a standard Multiwatt package; the microcircuit has found its niche in high-quality stereo technology, Hi-Fi class. The simple switching circuit and excellent parameters made the TDA7265 a perfectly balanced and excellent solution for building high-quality amateur radio equipment.
First, a test version was assembled on a breadboard exactly as shown in the datasheet in the link above, and successfully tested on S90 speakers. The sound is not bad, but something was missing. After some time, I decided to remake the amplifier using a modified circuit.
The microassembly is a quad class AB amplifier designed specifically for use in car audio devices. Based on this microcircuit, you can build several high-quality ULF options using a minimum of radio components. The microcircuit can be recommended to beginning radio amateurs for home assembly of various speaker systems.
The main advantage of the amplifier circuit on this microassembly is the presence of four channels independent of each other. This power amplifier operates in AB mode. It can be used to amplify various stereo signals. If desired, you can connect it to the speaker system of a car or personal computer.
The TDA8560Q is just a more powerful analogue of the TDA1557Q chip, widely known to radio amateurs. The developers have only strengthened the output stage, making the ULF perfectly suited to a two-ohm load.
The LM386 microassembly is a ready-made power amplifier that can be used in designs with low supply voltage. For example, when powering the circuit from a battery. LM386 has a voltage gain of about 20. But by connecting external resistances and capacitances, the gain can be adjusted up to 200, and the output voltage automatically becomes equal to half the supply voltage.
The LM3886 microassembly is a high quality amplifier with an output power of 68 watts into a 4 ohm load or 50 watts into 8 ohms. At peak moment, the output power can reach 135 W. A wide voltage range from 20 to 94 volts is applicable to the microcircuit. Moreover, you can use both bipolar and unipolar power supplies. The ULF harmonic coefficient is 0.03%. Moreover, this is over the entire frequency range from 20 to 20,000 Hz.
The circuit uses two ICs in a typical connection - KR548UH1 as a microphone amplifier (installed in the PTT switch) and (TDA2005) in a bridge connection as a final amplifier (installed in the siren housing instead of the original board). A modified alarm siren with a magnetic head is used as an acoustic emitter (piezo emitters are not suitable). The modification consists of disassembling the siren and throwing out the original tweeter with an amplifier. The microphone is electrodynamic. When using an electret microphone (for example, from Chinese handsets), the connection point between the microphone and the capacitor must be connected via a ~4.7K resistor to +12V (after the button!). The 100K resistor in the K548UH1 feedback circuit is better set with a resistance of ~30-47K. This resistor is used to adjust the volume. It is better to install the TDA2004 chip on a small radiator.
Test and operate - with the emitter under the hood and the PTT in the cabin. Otherwise, squealing due to self-excitation is inevitable. A trimmer resistor sets the volume level so that there is no strong sound distortion and self-excitation. If the volume is insufficient (for example, a bad microphone) and there is a clear reserve of emitter power, you can increase the gain of the microphone amplifier by several times increasing the value of the trimmer in the feedback circuit (the one according to the 100K circuit). In a good way, we would also need a primabass that would prevent the circuit from self-exciting - some kind of phase-shifting chain or a filter for the excitation frequency. Although the scheme works fine without complications
An old friend is better than two new ones!
Proverb
Thanks to a small number of wiring elements, the TDA2822M integrated circuit is one of the simple amplifiers that can be assembled in a short time, connected to an MP3 player, laptop, radio - and immediately evaluate the result of your work.
This is how attractive the description looks:
“TDA2822M is a stereo, two-channel low-voltage amplifier for portable equipment, etc.
It can be bridged, used as a headphone or control amplifier, and much more.
Operating supply voltage: 1.8 V to 12 V, power up to 1 W per channel, distortion up to 0.2%. No radiator required.
Despite its super-miniature size, it produces honest bass. The ideal chip for beginners' inhumane experiences."
With my article, I tried to help fellow radio amateurs make experiments with this interesting chip more conscious and humane.
Let's look at the chip housing
There are two microcircuits: one TDA2822, the other with the index “M” - TDA2822M.Integral chip TDA2822(Philips) is designed to create simple audio power amplifiers. The permissible range of supply voltages is 3…15 V; at Upit=6 V, Rн=4 Ohm, the output power is up to 0.65 W per channel, in the frequency band 30 Hz...18 kHz. Powerdip 16 chip package.
Chip TDA2822M it is made in a different Minidip 8 package and has a different pinout with a slightly lower maximum power dissipation (1 W versus 1.25 W for the TDA2822).
Please note that there are no other built-in protection circuits for the output stage, which is done for reasons of better use of the power supply, unfortunately at the expense of reliability.
Pins 5 and 8 of the microcircuit are connected to the common wire via alternating current. In this case, the gain of the amplifier with negative feedback will be:
Ku=20lg(1+R1/R2)= 20lg(1+R5/R4)=39 dB.
The block diagram of the IS is shown in Fig. 2.
Rice. 2. Block diagram of TDA2822M
It was experimentally determined that the sum of the resistances of resistors R1+R2 and R5+R4 is equal to 51.575 kOhm. Knowing the gain, it is easy to calculate that R1=R5=51 kOhm, and R2=R4=0.575 kOhm.
To reduce the gain of an OOS microcircuit, an additional resistor is usually connected in series with R2 (R4). In this case, such a circuitry technique is “interfered” with open transistor switches on transistors Q12 (Q13).
But even if we assume that the keys do not affect the feedback gain, the maneuver to reduce the gain is insignificant - no more than 3 dB; otherwise, the stability of the amplifier covered by OOS is not guaranteed.
Therefore, you can experiment with changing the transmission coefficient of the amplifier, taking into account that the resistance of the additional resistor lies in the range of 100...240 Ohms.
Rice. 3. Schematic diagram of an experimental stereo amplifier
The amplifier has the following characteristics:
Supply voltage Up=1.8…12 V
Output voltage Uout=2…4 V
Current consumption in quiescent mode Io=6…12 mA
Output power Pout=0.45…1.7 W
Gain Ku=36…41 (39) dB
Input resistance Rin=9.0 kOhm
Crosstalk attenuation between channels is 50 dB.
From a practical point of view, for reliable operation of the amplifier, it is advisable to set the supply voltage to no more than 9 V; in this case, for a load Rн=8 Ohm the output power will be 2x1.0 W, for Rн=16 Ohm - 2x0.6 W and for Rн=32 Ohm - 2x0.3 W. With load resistance Rн=4 Ohm, the optimal supply voltage will be up to 6 V (Pout=2x0.65 W).
The gain of the microcircuit of 39 dB, even taking into account a small downward adjustment by resistors R5, R6, turns out to be excessive for modern signal sources with a voltage of 250...750 mV. For example, for Up=9 V, Rн=8 Ohm, the sensitivity from the input is about 30 mV.
In Fig. 4, a shows the amplifier connection circuit, which allows you to connect a personal computer, MP3 player or radio receiver with a signal level of about 350 mV. For devices with an output signal of 250 mV, the resistance of resistors R1, R2 must be reduced to 33 kOhm; at an output signal level of 0.5 V, resistors R1=R2=68 kOhm, 0.75 V – 110 kOhm should be installed.
Double resistor R3 sets the required volume level. Capacitors C1, C2 are transitional.
Rice. 4. UMZCH connection diagram: a) - to speaker systems, b) - to headphones (headphones)
In Fig. 4, b shows the connection to the amplifier of the headphone jack. Resistors R4, R5 eliminate clicks when connecting stereo phones, resistors R6, R7 limit the volume level.
During the experiments, I tried to power the UMZCH both from a stabilized power supply (on an integrated circuit and a BD912 transistor), Fig. 5, and from a battery with a capacity of 7.2 Ah for a voltage of 12 V with a power supply for fixed voltages, Fig. 6.
The supply voltage is supplied by as short a pair of wires as possible, twisted together.
A correctly assembled device does not require adjustment.
Fragment excluded. Our magazine exists on donations from readers. The full version of this article is available only
Rice. 5. Schematic diagram of a stabilized power supply
Fragment excluded. Our magazine exists on donations from readers. The full version of this article is available only
Rice. 6. Rechargeable battery - laboratory power source
A subjective assessment of the noise level showed that when the volume control is set to the maximum level, the noise is barely noticeable.
Subjective assessment of sound reproduction quality was made without comparison with the standard. The result is a good sound, listening to soundtracks does not cause irritation.
I checked the chip forums on the Internet, where I came across many messages about searching for unknown sources of noise, self-excitation and other troubles.
As a result, he developed a printed circuit board, the distinctive feature of which is the “star” grounding of the elements. A photo view of the printed circuit board from the Sprint-Layout program is shown in Fig. 7.
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Rice. 7. Placement of parts on the experimental printed circuit board
During experiments on this signet, it was not possible to encounter any of the artifacts described on the forums.
Details of the stereo UMZCH on the TDA2822M chip
The printed circuit board is designed for installation of the most common parts: MLT, S2-33, S1-4 or imported resistors with a power of 0.125 or 0.25 W, film capacitors K73-17, K73-24 or imported MKT, imported oxide capacitors.
I used inexpensive but reliable electrolytic capacitors with low impedance, long service life (5000 hours) and the ability to operate at temperatures up to +105°C from Hitano ESX, EHR and EXR series. It should be remembered that the larger the outer diameter of the capacitor in the series, the longer its service life.
The DA1 chip is installed in an eight-pin socket. The TDA2822M chip can be replaced with KA2209B (Samsung) or K174UN34 (Angstrem OJSC, Zelenograd). CHIP capacitor C8 (SMD) is located on the side of the printed tracks.
R5, R6 - Res.-0.25-160 Ohm (Brown, blue, brown, golden) - 2 pcs.,
C3 - C5 - Cond. 1000/16V 1021+105°C - 3 pcs.,
C6, C7 - Cond. 0.1/63V K73-17 - 2 pcs.,
C8 - Cond.0805 0.1µF X7R smd – 1 pc.
Many radio amateurs, not without reason, believe that it is best to include microcircuits in accordance with the Datasheet and use printed circuit boards offered by the developers.
Below are diagrams and printed circuit boards made on the basis of the documentation with the only modification - to increase the stability of the amplifier, a film capacitor is connected in parallel to the oxide capacitor along the power supply circuit (Fig. 8, 9).
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Rice. 8. Typical circuit diagram for connecting a microcircuit in stereo mode
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Rice. 9. Placement of elements of a typical stereo UMZCH
Details of a typical stereo UMZCH
When installing elements on a printed circuit board, I advise you to use simple technological techniques described in the Datagor article.
DA1 - TDA2822M ST Housing: DIP8-300 - 1 pc.,
SCS-8 Narrow dip socket - 1 pc.,
R1, R2 - Res.-0.25-10k (Brown, black, orange, golden) - 2 pcs.,
R3, R4 - Res. -0.25-4.7 Ohm (Yellow, purple, golden, golden) - 2 pcs.,
C1, C2 - Cond. 100/16V 0611 +105°C - 2 pcs.,
C3 - Cond. 10/16V 0511 +105°C (Capacitance can be increased to 470 µF) - 1 pc.,
C4, C5 - Cond. 470/16V 1013+105°C - 2 pcs.,
C6 – C8 - Cond. 0.1/63V K73-17 - 3 pcs.
Rice. 10. Schematic diagram of an experimental bridge amplifier
Unlike the stereo amplifier circuit (Fig. 3), which assumes that coupling capacitors are present at the output of the previous device, a coupling capacitor is included at the input of the bridge amplifier, which determines the lower frequency reproduced by the amplifier.
Depending on the specific application, the capacitance of capacitor C1 can be from 0.1 μF (fn = 180 Hz) to 0.68 μF (fn = 25 Hz) or more. With capacitance C1 indicated on the circuit diagram, the lower frequency of the reproduced frequencies is 80 Hz.
Internal resistors connected to the inverting inputs of the amplifier through an isolation capacitor C2 are connected to each other, which provides output signals of equal magnitude but opposite in phase.
Capacitor C3 corrects the frequency response of the amplifier at high frequencies.
Since the DC output potentials of the amplifier are equal, it became possible to directly connect the load, without isolating capacitors.
The purpose of the remaining elements was described earlier.
For the stereo version, you will need two bridge amplifiers on the TDA2822M chip. The connection diagram is easy to obtain using Fig. 4.
Reliable operation of the amplifier in bridge mode is ensured by selecting the appropriate supply voltage depending on the load resistance (see table).
All parts of the bridge amplifier are placed on a printed circuit board measuring 32 x 38 mm made of one-sided foil fiberglass 2 mm thick. A drawing of a possible board option is shown in Fig. eleven.
Rice. 11. Placement of elements on the bridge amplifier board
DA1 - TDA2822M ST Housing: DIP8-300 - 1 pc.,
SCS-8 Narrow dip socket - 1 pc.,
R1 - Res.-0.25-10k (Brown, black, orange, gold) - 1 pc.,
R2, R3 - Res. -0.25-4.7 Ohm (Yellow, purple, golden, golden) - 2 pcs.,
C1 - Cond. 0.22/63V K73-17 - 1 pc.,
C2 - Cond. 10/16V 0511 +105°C - 1 pc.,
C3 - Cond.0.01/630V K73-17 - 1 pc.,
C4 – C6 - Cond.0.1/63V K73-17 - 3 pcs.,
C7 - Cond. 1000/16V 1021+105°C - 1 pc.
The schematic diagram of a typical bridge UMZCH and the placement of elements on the printed circuit board are shown respectively in Fig. 12 and 13.
In this article I will tell you about a microcircuit such as TDA1514A
Introduction
Let me start with something sad... At the moment, production of the microcircuit has been discontinued... But this does not mean that it is now “worth its weight in gold”, no. You can get it in almost any radio store or radio market for 100 - 500 rubles. Agree, a little expensive, but the price is absolutely fair! By the way, on global Internet sites such as these they are much cheaper...
The microcircuit is characterized by a low level of distortion and a wide range of reproduced frequencies, so it is better to use it on full-range speakers. People who have assembled amplifiers using this chip praise it for its high sound quality. This is one of the few microcircuits that truly “sounds well.” The sound quality is in no way inferior to the currently popular TDA7293/94. However, if errors are made in the assembly, high-quality work is not guaranteed.
Brief description and advantages
This chip is a single-channel Hi-Fi amplifier of class AB, the power of which is 50W. The chip has built-in SOAR protection, thermal protection (overheating protection) and a "Mute" mode.
The advantages include the absence of clicks when turning on and off, the presence of protection, low harmonic and intermodulation distortion, low thermal resistance, and more. There is practically nothing to highlight among the shortcomings, except failure when the voltage “runs” (the power supply must be more or less stable) and the relatively high price
Briefly about appearance
The chip is available in a SIP package with 9 long legs. The pitch of the legs is 2.54mm. On the front side there are inscriptions and a logo, and on the back there is a heat sink - it is connected to the 4th leg, and the 4th leg is the “-” power supply. There are 2 eyelets on the sides for attaching the radiator.
The original or a fake?
Many people ask this question, I will try to answer you.
So. The microcircuit must be carefully made, the legs must be smooth, minor deformation is allowed, since it is unknown how they were handled in a warehouse or store
The inscription... It can be made either with white paint or with a regular laser, the two chips above are for comparison (both are original). If the inscription is painted, there should ALWAYS be a vertical stripe on the chip, separated by an eyelet. Don't be confused by the "TAIWAN" inscription - it's okay, the sound quality of such copies is no worse than those without this inscription. By the way, almost half of the radio components are made in Taiwan and neighboring countries. This inscription is not found on all microcircuits.
I also advise you to pay attention to the second line. If it contains only numbers (there should be 5 of them) - these are “old” production microcircuits. The inscription on them is wider, and the heat sink may also have a different shape. If the inscription on the microcircuit is applied with a laser and the second line contains only 5 digits, there should be a vertical stripe on the microcircuit
The logo on the microcircuit must be present and only “PHILIPS”! As far as I know, production ceased long before NXP was founded, and this is 2006. If you come across this microcircuit with the NXP logo, there is one of two things - they started producing the microcircuit again or it is a typical “leftist”
It is also necessary to have depressions in the shape of circles, as in the photo. If they are not there, it is a fake.
Perhaps there are still ways to identify the “leftist”, but you shouldn’t stress over this issue so much. There are only a few cases of marriage.
Technical characteristics of the microcircuit
* Input impedance and gain are adjusted by external elements
Below is a table of approximate output powers depending on power supply and load resistance
| Supply voltage | Load resistance | ||
| 4 ohm | 8 ohm | ||
| 10W | 6W | ||
| +-16.5V |
28W |
12W | |
| 48W | 28W | ||
| 58W | 32W | ||
| 69W | 40W | ||
Schematic diagram
The diagram is taken from the datasheet (May 1992)
It's too bulky... I had to redraw it:
The circuit differs slightly from that provided by the manufacturer, all the characteristics given above are exactly for THIS circuit. There are several differences and they are all aimed at improving the sound - first of all, filter capacitors were installed, the “voltage boost” was removed (more on that a little later) and the value of resistor R6 was changed.
Now in more detail about each component. C1 is the input coupling capacitor. It passes through only the alternating voltage signal. It also affects the frequency response - the smaller the capacitance, the smaller the bass and, accordingly, the larger the capacitance, the greater the bass. I would not recommend setting it to more than 4.7 µF, since the manufacturer has provided for everything - with the capacitance of this capacitor equal to 1 µF, the amplifier reproduces the declared frequencies. Use a film capacitor, in extreme cases an electrolytic one (non-polar is desirable), but not a ceramic one! R1 reduces the input resistance, and together with C2 forms a filter against input noise.
As with any operational amplifier, the gain can be set here. This is done using R2 and R7. At these ratings, the gain is 30 dB (may deviate slightly). C4 affects the activation of SOAR and Mute protection, R5 affects the smooth charging and discharging of the capacitor, and therefore there are no clicks when the amplifier is turned on and off. C5 and R6 form the so-called Zobel chain. Its task is to prevent the amplifier from self-excitation, as well as to stabilize the frequency response. C6-C10 suppress power supply ripples and protect against voltage sags.
The resistors in this circuit can be taken with any power, for example I use the standard 0.25W. Capacitors for a voltage of at least 35V, except for C10 - I use 100V in my circuit, although 63V should be enough. All components must be checked for serviceability before soldering!
Amplifier circuit with "voltage boost"
This version of the circuit is taken from the datasheet. It differs from the above-described scheme in the presence of elements C3, R3 and R4.
This option will allow you to get up to 4W more than stated (at ±23V). But with this inclusion, distortion may increase slightly. Resistors R3 and R4 should be used at 0.25W. I couldn’t handle it at 0.125W. Capacitor C3 - 35V and above.
This circuit requires the use of two microcircuits. One gives a positive signal at the output, the other a negative one. With this connection, you can remove more than 100W into 8 ohms.
According to those who gathered, this scheme is absolutely workable and I even have a more detailed table of approximate output powers. It's below:
And if you experiment, for example, at ±23V you connect a 4 ohm load, you can get up to 200W! Provided that the radiators do not heat up too much, the 150W microcircuit will be easily pulled into the bridge.
This design is good to use in subwoofers.
Operation with external output transistors
The microcircuit is essentially a powerful operational amplifier and it can be further boosted by adding a pair of complementary transistors to the output. This option has not yet been tested, but it is theoretically possible. You can also power up the bridge circuit of the amplifier by attaching a pair of complementary transistors to the output of each microcircuit
Operation with unipolar power supply
At the very beginning of the datasheet, I found lines that say that the microcircuit also works with single-supply power. Where is the diagram then? Alas, it’s not in the datasheet, I couldn’t find it on the Internet... I don’t know, maybe such a circuit exists somewhere, but I haven’t seen one... The only thing I can recommend is TDA1512 or TDA1520. The sound is excellent, but they are powered from a single-polar supply, and the output capacitor can slightly spoil the picture. Finding them is quite problematic; they were produced a very long time ago and were discontinued a long time ago. The inscriptions on them can be of various shapes; there is no need to check them for “fake” - there have been no cases of refusal.
Both microcircuits are Hi-Fi class AB amplifiers. Power is about 20W at +33V into a 4 ohm load. I won’t give the diagrams (the topic is still about the TDA1514A). You can download printed circuit boards for them at the end of the article.
Nutrition
For stable operation of the microcircuit, you need a power source with a voltage from ±8 to ±30V with a current of at least 1.5A. Power must be supplied with thick wires, the input wires should be kept as far away from the output wires and the power source as possible
You can power it with an ordinary simple power supply, which includes a mains transformer, a diode bridge, filter tanks and, if desired, chokes. To obtain ±24V, you need a transformer with two 18V secondary windings with a current of more than 1.5A for one microcircuit.
You can use switching power supplies, for example the simplest one, on IR2153. Here is his diagram:
This UPS is made using a half-bridge circuit, frequency 47 kHz (set using R4 and C4). Diodes VD3-VD6 ultrafast or Schottky
It is possible to use this amplifier in a car using a boost converter. On the same IR2153, here is the diagram:
The converter is made according to the Push-Pull scheme. Frequency 47kHz. Rectifier diodes need ultrafast or Schottky ones. Transformer calculations can also be performed in ExcellentIT. The chokes in both schemes will be “recommended” by ExcellentIT itself. You need to count them in the Drossel program. The author of the program is the same -
I would like to say a few words about the IR2153 - the power supplies and converters are quite good, but the microcircuit does not provide stabilization of the output voltage and therefore it will change depending on the supply voltage, and it will also sag.
It is not necessary to use IR2153 or switching power supplies in general. You can do it simpler - like in the old days, a regular transformer with a diode bridge and huge power supply capacities. This is what its diagram looks like:
C1 and C4 at least 4700 µF, for a voltage of at least 35V. C2 and C3 - ceramics or film.
Printed circuit boards
Now I have the following collection of boards:
a) the main one - it can be seen in the photo below.
b) slightly modified first (main). All tracks have been increased in width, the power ones are much wider, the elements have been slightly moved.
c) bridge circuit. The board is not drawn very well, but it is functional
d) the first version of the PP is the first trial version, there is not enough Zobel chain, but I assembled it this way and it works. There is even a photo (below)
d) printed circuit board fromXandR_man - found it on the forum of the Soldering Iron site. What can I say... Strictly a diagram from the datasheet. Moreover, I saw with my own eyes sets based on this signet!
In addition, you can draw the board yourself if you are not satisfied with the ones provided.
Soldering
After you have made the board and checked all the parts for serviceability, you can start soldering.
Tin the entire board, and tin the power traces with as thick a layer of solder as possible
All jumpers are soldered in first (their thickness should be as large as possible in the power sections), and then all components increase in size. The microcircuit is soldered last. I advise you not to cut the legs, but solder them as they are. You can then bend it to make it easier to fit on the radiator.
The microcircuit is protected from static electricity, so you can solder with the soldering iron turned on, even while sitting in woolen clothes.
However, it is necessary to solder so that the chip does not overheat. For reliability, you can attach it to the radiator by one eye during soldering. You can do it in two, there won’t be any difference, as long as the crystal inside doesn’t overheat.
Setup and first launch
After all the elements and wires are soldered, a “test run” is necessary. Screw the microcircuit onto the radiator and connect the input wire to ground. You can connect future speakers as a load, but in general, to prevent them from “flying out” in a split second due to defects or installation errors, use a powerful resistor as a load. If it crashes, you know that you made a mistake, or you got a defect (the microcircuit is meant). Fortunately, such cases almost never happen, unlike TDA7293 and others, of which you can get a bunch of them from one batch in a store and, as it turns out later, they are all defective.
However, I want to make a small note. Keep your wires as short as possible. It happened that I just lengthened the output wires and began to hear a hum in the speakers, similar to “constant”. Moreover, when the amplifier was turned on, due to the “constant” mode, the speaker produced a hum that disappeared after 1-2 seconds. Now I have wires coming out of the board, a maximum of 25 cm and going straight to the speaker - the amplifier turns on silently and works without problems! Also pay attention to the input wires - use a shielded wire; it shouldn’t be long either. Follow simple requirements and you will succeed!
If nothing happened to the resistor, turn off the power, attach the input wires to the signal source, connect your speakers and apply power. You can hear a slight hum in the speakers - this indicates that the amplifier is working! Give a signal and enjoy the sound (if everything is perfectly assembled). If it “grunts” or “farts” - look at the food, at the correctness of assembly, because, as has been discovered in practice, there are no such “nasty” specimens that, with proper assembly and excellent nutrition, worked crookedly...
What the finished amplifier looks like
Here is a series of photographs taken in December 2012. The boards are just after soldering. Then I assembled it to make sure the microcircuits were working.
But my first amplifier, only the board has survived to this day, all the parts went to other circuits, and the microcircuit itself failed due to alternating voltage coming into contact with it
Below are the latest photos:
Unfortunately, my UPS is at the manufacturing stage, and I previously powered the microcircuit from two identical batteries and a small transformer with a diode bridge and small power supply capacities, in the end it was±25V. Two such microcircuits with four speakers from the Sharp music center played so well that even the objects on the tables “danced to the music,” the windows rang, and the body felt the power quite well. I can’t remove this now, but there is a ±16V power supply, from it you can get up to 20W at 4 ohms... Here is a video for you as proof that the amplifier is absolutely working!
Acknowledgments
I express my deep gratitude to the users of the “Soldering Iron” site forum, and specifically, a huge thank you to the user for some help, and I also thank many others (sorry for not calling you by nickname) for their honest feedback, which pushed me to build this amplifier. Without all of you, this article might not have been written.
Completion
The microcircuit has a number of advantages, first of all, excellent sound. Many microcircuits of this class may even be inferior in sound quality, but this depends on the quality of the assembly. Bad assembly - bad sound. Take electronic circuit assembly seriously. I strongly do not recommend soldering this amplifier by surface mounting - this can only worsen the sound, or lead to self-excitation, and subsequently complete failure.
I collected almost all the information that I checked myself and could ask other people who assembled this amplifier. It's a pity that I don't have an oscilloscope - without it, my statements about sound quality mean nothing... But I will continue to say that it sounds just great! Those who collected this amplifier will understand me!
If you have any questions, write to me on the forum of the Soldering Iron site. to discuss amplifiers on this chip, you can ask there.
I hope the article was useful to you. Good luck to you! Regards, Yuri.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad | |
|---|---|---|---|---|---|---|---|
| Chip | TDA1514A | 1 | To notepad | ||||
| C1 | Capacitor | 1 µF | 1 | To notepad | |||
| C2 | Capacitor | 220 pF | 1 | To notepad | |||
| C4 | 3.3uF | 1 | To notepad | ||||
| C5 | Capacitor | 22 nF | 1 | To notepad | |||
| C6, C8 | Electrolytic capacitor | 1000uF | 2 | To notepad | |||
| S7, S9 | Capacitor | 470 nF | 2 | To notepad | |||
| C10 | Electrolytic capacitor | 100uF | 1 | 100V | To notepad | ||
| R1 | Resistor | 20 kOhm | 1 | To notepad | |||
| R2 | Resistor | 680 Ohm | 1 | To notepad | |||
| R5 | Resistor | 470 kOhm | 1 | To notepad | |||
| R6 | Resistor | 10 ohm | 1 | Selected during setup | To notepad | ||
| R7 | Resistor | 22 kOhm | 1 | To notepad | |||
| Circuit with voltage boost | |||||||
| Chip | TDA1514A | 1 | To notepad | ||||
| C1 | Capacitor | 1 µF | 1 | To notepad | |||
| C2 | Capacitor | 220 pF | 1 | To notepad | |||
| C3 | Electrolytic capacitor | 220uF | 1 | From 35V and above | To notepad | ||
| C4 | Electrolytic capacitor | 3.3uF | 1 | To notepad | |||
| C5 | Capacitor | 22 nF | 1 | To notepad | |||
| C6, C8 | Electrolytic capacitor | 1000uF | 2 | To notepad | |||
| S7, S9 | Capacitor | 470 nF | 2 | To notepad | |||
| C10 | Electrolytic capacitor | 100uF | 1 | 100V | To notepad | ||
| R1 | Resistor | 20 kOhm | 1 | To notepad | |||
| R2 | Resistor | 680 Ohm | 1 | To notepad | |||
| R3 | Resistor | 47 Ohm | 1 | Selected during setup | To notepad | ||
| R4 | Resistor | 82 Ohm | 1 | Selected during setup | To notepad | ||
| R5 | Resistor | 470 kOhm | 1 | To notepad | |||
| R6 | Resistor | 10 ohm | 1 | Selected during setup | To notepad | ||
| R7 | Resistor | 22 kOhm | 1 | To notepad | |||
| Bridge connection | |||||||
| Chip | TDA1514A | 2 | To notepad | ||||
| C1 | Capacitor | 1 µF | 1 | To notepad | |||
| C2 | Capacitor | 220 pF | 1 | To notepad | |||
| C4 | Electrolytic capacitor | 3.3uF | 1 | To notepad | |||
| C5, C14, C16 | Capacitor | 22 nF | 3 | To notepad | |||
| C6, C8 | Electrolytic capacitor | 1000uF | 2 | To notepad | |||
| S7, S9 | Capacitor | 470 nF | 2 | To notepad | |||
| C13, C15 | Electrolytic capacitor | 3.3uF | 2 | To notepad | |||
| R1, R7 | Resistor | 20 kOhm | 2 | To notepad | |||
| R2, R8 | Resistor | 680 Ohm | 2 | To notepad | |||
| R5, R9 | Resistor | 470 kOhm | 2 | To notepad | |||
| R6, R10 | Resistor | 10 ohm | 2 | Selected during setup | To notepad | ||
| R11 | Resistor | 1.3 kOhm | 1 | To notepad | |||
| R12, R13 | Resistor | 22 kOhm | 2 | To notepad | |||
| Impulse power block | |||||||
| IC1 | Power Driver and MOSFET | IR2153 | 1 | To notepad | |||
| VT1, VT2 | MOSFET transistor | IRF740 | 2 | To notepad | |||
| VD1, VD2 | Rectifier diode | SF18 | 2 | To notepad | |||
| VD3-VD6 | Diode | Any Schottky | 4 | Ultrafast diodes or Schottky | To notepad | ||
| VDS1 | Diode bridge | 1 | Diode bridge for the required current | To notepad | |||
| C1, C2 | Electrolytic capacitor | 680uF | 2 | 200V | To notepad | ||
| C3 | Capacitor | 10 nF | 1 | 400V | To notepad | ||
| C4 | Capacitor | 1000 pF | 1 | To notepad | |||
| C5 | Electrolytic capacitor | 100uF | 1 | To notepad | |||
| C6 | Capacitor | 470 nF | 1 | To notepad | |||
| C7 | Capacitor | 1 nF | 1 | ||||
