Power supplies for ULF circuits and seals. Transformers for umzch
The audio frequency amplifier (UHF), or low frequency amplifier (ULF) is one of the most common electronic devices. We all receive sound information using one or another type of ULF. Not everyone knows, but low-frequency amplifiers are also used in measuring technology, flaw detection, automation, telemechanics, analog computing and other areas of electronics.
Although, of course, the main application of ULF is to convey a sound signal to our ears with the help of acoustic systems that convert electrical vibrations into acoustic ones. And the amplifier should do this as accurately as possible. Only in this case we get the pleasure that our favorite music, sounds and speech give us.
From the appearance of Thomas Edison's phonograph in 1877 to the present day, scientists and engineers have struggled to improve the basic parameters of ULF: primarily for the reliability of the transmission of sound signals, as well as for consumer characteristics, such as power consumption, dimensions, ease of manufacture, adjustment and use.
Since the 1920s, a letter classification of electronic amplifier classes has been formed, which is still used today. Classes of amplifiers differ in the operating modes of the active electronic devices used in them - vacuum tubes, transistors, etc. The main "single-letter" classes are A, B, C, D, E, F, G, H. Class designation letters can be combined if some modes are combined. The classification is not a standard, so developers and manufacturers can use the letters quite arbitrarily.
Class D occupies a special place in the classification. Active elements of the ULF output stage of class D operate in the key (pulse) mode, unlike other classes, where the linear mode of operation of active elements is mostly used.
One of the main advantages of class D amplifiers is the coefficient of performance (COP), approaching 100%. This, in particular, leads to a decrease in the power dissipated by the active elements of the amplifier, and, as a result, to a decrease in the size of the amplifier due to a decrease in the size of the radiator. Such amplifiers impose much lower requirements on the quality of the power supply, which can be unipolar and pulsed. Another advantage can be considered the possibility of using digital signal processing methods and digital control of their functions in class D amplifiers - after all, it is digital technologies that prevail in modern electronics.
Taking into account all these trends, Master Kit offers wide range of class amplifiersD, assembled on the same TPA3116D2 chip, but having different purposes and power. And so that buyers do not waste time looking for a suitable power source, we have prepared amplifier + power supply kits optimally matched to each other.
In this review, we will look at three such kits:
- (LF amplifier D-class 2x50W + power supply 24V / 100W / 4.5A);
- (LF amplifier D-class 2x100W + power supply 24V / 200W / 8.8A);
- (D-class bass amplifier 1x150W + power supply 24V / 200W / 8.8A).
First set It is intended primarily for those who need minimal dimensions, stereo sound and a classic control scheme simultaneously in two channels: volume, bass and treble. It includes and .
The two-channel amplifier itself has an unprecedentedly small size: only 60 x 31 x 13 mm, not including knobs. The dimensions of the power supply are 129 x 97 x 30 mm, weight is about 340 g.
Despite its small size, the amplifier delivers honest 50 watts per channel into a 4 ohm load at a supply voltage of 21 volts!
The RC4508 chip is used as a pre-amplifier - a dual specialized operational amplifier for audio signals. It allows you to perfectly match the input of the amplifier with the signal source, has extremely low non-linear distortion and noise level.
The input signal is fed to a three-pin connector with a pin pitch of 2.54 mm, the supply voltage and speakers are connected using convenient screw connectors.
A small heatsink is installed on the TPA3116 chip using heat-conducting glue, the dissipation area of which is quite enough even at maximum power.
Please note that in order to save space and reduce the size of the amplifier, there is no protection against reverse polarity of the power supply connection (polarity reversal), so be careful when applying power to the amplifier.
Given the small size and efficiency, the scope of the kit is very wide - from replacing an outdated or failed old amplifier to a very mobile sound amplification kit for scoring an event or party.
An example of the use of such an amplifier is given.
There are no mounting holes on the board, but for this you can successfully use potentiometers that have fasteners for the nut.
Second set includes two TPA3116D2 chips, each of which is connected in bridged mode and provides up to 100 watts of output power per channel, as well as with an output voltage of 24 volts and a power of 200 watts.
With this kit and two 100-watt speakers, you can sound a solid event even outdoors!
The amplifier is equipped with a volume control with a switch. The board has a powerful Schottky diode to protect against polarity reversal of the power supply.
The amplifier is equipped with effective low-pass filters, installed according to the recommendations of the manufacturer of the TPA3116 chip, and together with it provide a high quality output signal.
The supply voltage and acoustic systems are connected using screw connectors.
The input signal can be either a 3-pin 2.54mm pitch connector or a standard 3.5mm audio jack.
The radiator provides sufficient cooling for both microcircuits and is pressed against their thermal pads with a screw located on the bottom of the printed circuit board.
For ease of use, the board also has a green LED that indicates power on.
The dimensions of the board, including capacitors and excluding the potentiometer knob, are 105 x 65 x 24 mm, the distances between the mounting holes are 98.6 and 58.8 mm. Power supply dimensions 215 x 115 x 30 mm, weight approx. 660 g.
Third set represents l and with an output voltage of 24 volts and a power of 200 watts.
The amplifier provides up to 150 watts of output power into a 4 ohm load. The main application of this amplifier is the construction of a high-quality and energy-efficient subwoofer.
Compared to many other dedicated subwoofer amplifiers, the MP3116btl is great at driving fairly large diameter woofers. This is confirmed by customer reviews of the considered ULF. The sound is rich and bright.
The radiator, which occupies most of the PCB area, provides efficient cooling of the TPA3116.
To match the input signal at the input of the amplifier, the NE5532 chip is used - a two-channel low-noise specialized operational amplifier. It has minimal non-linear distortion and a wide bandwidth.
The input also has an input signal amplitude control with a slot for a screwdriver. It allows you to adjust the volume of the subwoofer to the volume of the main channels.
To protect against polarity reversal of the supply voltage, a Schottky diode is installed on the board.
Power and speakers are connected using screw connectors.
The dimensions of the amplifier board are 73 x 77 x 16 mm, the distance between the mounting holes is 69.4 and 57.2 mm. Power supply dimensions 215 x 115 x 30 mm, weight approx. 660 g.
All kits include switching power supplies from MEAN WELL.
Founded in 1982, the company is the leading manufacturer of switching power supplies in the world. Currently, MEAN WELL Corporation consists of five financially independent partner companies in Taiwan, China, the United States and Europe.
MEAN WELL products are characterized by high quality, low failure rate and long service life.
Switching power supplies, developed on a modern element base, meet the highest requirements for the quality of the output DC voltage and differ from conventional linear power supplies in their low weight and high efficiency, as well as the presence of protection against overload and short circuit at the output.
The power supplies LRS-100-24 and LRS-200-24 used in the presented kits have an LED power indicator and a potentiometer for fine adjustment of the output voltage. Before connecting the amplifier, check the output voltage, and if necessary, set its level to 24 volts using a potentiometer.
The applied sources use passive cooling, so they are completely silent.
It should be noted that all the considered amplifiers can be successfully used to design sound reproducing systems for cars, motorcycles and even bicycles. When the amplifiers are powered by 12 volts, the output power will be somewhat less, but the sound quality will not suffer, and the high efficiency makes it possible to effectively power the ULF from autonomous power sources.
We also draw your attention to the fact that all the devices discussed in this review can be purchased separately and as part of other kits on the site.
Other articles on the construction of this ULF.
Schematic diagram of the power supply.
The power supply is assembled according to one of the standard schemes. A bipolar power supply is selected to power the final amplifiers. This allows the use of low cost, high quality integrated amplifiers and eliminates a number of problems associated with supply voltage ripple and turn-on transients. https://website/
The power supply must provide power to three microcircuits and one LED. Two TDA2030 microcircuits are used as final power amplifiers, and one TDA1524A microcircuit is used as a volume control, stereo base and tone control.
The electrical circuit of the power supply.
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VD3... VD6 - KD226 |
C1-680mkFx25V C3... C6 - 1000mkFx25V |
On diodes VD3 ... VD6, a bipolar full-wave rectifier with a midpoint is assembled. This switching circuit reduces the voltage drop across the rectifier diodes by half compared to a conventional bridge rectifier, since current flows through only one diode in each half-cycle.
Electrolytic capacitors C3 ... C6 are used as a rectified voltage filter.
On the IC1 chip, a voltage regulator is assembled to power the electronic volume control circuit, stereo base and tone. The stabilizer is assembled according to a standard scheme.
The use of the LM317 chip is due only to the fact that it was available. Here you can apply any integral stabilizer.
The protective diode VD2, indicated by a dotted line, is not necessary when the output voltage on the LM317 chip is below 25 volts. But, if the input voltage of the microcircuit is 25 Volts and higher, and the resistor R3 is trimmer, then it is better to install the diode.
The value of the resistor R3 determines the output voltage of the stabilizer. During prototyping, I soldered a trimmer instead, set the voltage to about 9 volts at the output of the stabilizer with it, and then measured the resistance of this trimmer so that I could install a constant resistor instead.
The rectifier that feeds the stabilizer is made according to a simplified half-wave circuit, which is dictated by purely economic considerations. Four diodes and one capacitor cost more than one diode and one slightly larger capacitor.
The current consumed by the TDA1524A chip is only 35mA, so this scheme is fully justified.
LED HL1 - power-on indicator of the amplifier. A ballast resistor of this indicator is installed on the power supply board - R1 with a nominal resistance of 500 Ohms. The current of the LED depends on the resistance of this resistor. I used a green LED rated at 20mA. When using a red LED type AL307 for a current of 5mA, the resistance of the resistor can be increased by 3-4 times.
Printed circuit board.
The printed circuit board (PCB) is designed based on the design of a particular amplifier and the available electrical components. The board has only one mounting hole, located in the very center of the PCB, which is due to an unusual design.
To increase the cross-section of copper tracks and save ferric chloride, the places free from tracks on the PCB were filled using the "Polygon" tool.
Increasing the width of the tracks also prevents the peeling of the foil from the fiberglass in case of violation of the thermal regime or during repeated soldering of radio components.
According to the drawing given above, a printed circuit board was made of foil fiberglass with a cross section of 1 mm.
To connect the wires to the printed circuit board, copper pins (soldiers) were riveted in the holes of the board.
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And this is the already assembled printed circuit board of the power supply.
To see all six views, drag the picture with the cursor or use the arrow buttons located at the bottom of the picture.
The mesh on the PP copper tracks is the result of using this technology. 
When the board is assembled, it is desirable to test it even before connecting the final amplifiers and the regulator unit. To test the power supply, you need to connect a load equivalent to its outputs, as in the above diagram.
As a load of +12.8 and -12.8 Volt rectifiers, resistors of the PEV-10 type for 10-15 Ohms are suitable.
The voltage at the output of the stabilizer, loaded on a resistor with a resistance of 100-150 ohms, is a good idea to look with an oscilloscope for the absence of ripples when the AC input voltage is reduced from 14.3 to 10 volts.
P.S. Finalization of the printed circuit board.
During commissioning, the printed circuit board of the power supply came in.
When finalizing, I had to cut one track pos.1 and add one contact pos.2 to connect the transformer winding that feeds the voltage stabilizer.
Now, rarely does anyone introduce a network transformer into a home-made amplifier design, and rightly so - a pulsed power supply unit is cheaper, lighter and more compact, and a well-assembled one almost does not give interference to the load (or interference is minimized).
Of course, I don’t argue, the mains transformer is much, much more reliable, although modern impulse switches, stuffed with all sorts of protections, also do their job well.
IR2153 - I would say already a legendary microcircuit, which is used very often by radio amateurs, and is being introduced precisely into network switching power supplies. The microcircuit itself is a simple half-bridge driver and in SMPS circuits it works as a pulse generator.
Based on this microcircuit, power supplies from several tens to several hundred watts and even up to 1500 watts are built, of course, with increasing power, the circuit will become more complicated.
Nevertheless, I don’t see any reason to make a high power uip using this particular microcircuit, the reason is that it is impossible to organize output stabilization or control, and not only the microcircuit is not a PWM controller, therefore, there can be no talk of any PWM control, and this is very bad . Good IIPs are rightly made on push-pull PWM microcircuits, for example, TL494 or its relatives, etc., and the block on the IR2153 is more of an entry-level block.
Let's move on to the design of the switching power supply. Everything is assembled according to the datasheet - a typical half-bridge, two half-bridge capacities that are constantly in the charge / discharge cycle. The power of the circuit as a whole will depend on the capacitance of these capacitors (well, of course, not only on them). The estimated power of this particular option is 300 watts, I don’t need more, the unit itself is for powering two unch channels. The capacitance of each of the capacitors is 330 μF, the voltage is 200 Volts, in any computer power supply there are just such capacitors, in theory, the schematics of the computer power supplies and our unit are somewhat similar, in both cases the topology is a half-bridge.
At the input of the power supply, everything is also as it should be - a varistor for surge protection, a fuse, a surge protector and, of course, a rectifier. A full-fledged diode bridge, which you can take ready-made, the main thing is that the bridge or diodes have a reverse voltage of at least 400 volts, ideally 1000, and with a current of at least 3 amperes. The decoupling capacitor is a film, 250 V and preferably 400, a capacitance of 1 microfarad, by the way - can also be found in a computer power supply.
Transformer Calculated according to the program, the core is from a computer power supply unit, alas, I can’t indicate the overall dimensions. In my case, the primary winding is 37 Turns with a 0.8mm wire, the secondary is 2 to 11 turns with a bus of 4 wires 0.8mm. With this layout, the output voltage is in the region of 30-35 Volts, of course, the winding data will be different for everyone, depending on the type and overall dimensions of the core.
This project can be called the most ambitious in my practice, it took more than 3 months to implement this version. I want to say right away that I spent a lot of money on the project, fortunately many people helped with this, in particular I want to thank our respected site administrator RADIO SCHEMES for moral and financial support. So, first I want to introduce the general idea. It consisted in creating a powerful home-made car amplifier (although there is no car yet), which could provide high sound quality and feed about 10 powerful dynamic heads, in other words, a complete HI-FI audio complex for powering the front and rear acoustics. After 3 months, the complex was completely ready and tested, I must say that it fully justified all hopes, and I do not feel sorry for the money spent, nerves and a lot of time.The output power is quite high, since the main amplifier is built according to the famous LANZAR circuit, which provides a maximum power of 390 watts, but of course the amplifier does not operate at full power. This amplifier is designed to power the SONY XPLOD XS-GTX120L subwoofer head, head parameters are shown below.
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Rated power - 300 W
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Peak power - 1000 W
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Frequency range 30 - 1000 Hz
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Sensitivity - 86 dB
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Output impedance - 4 ohms
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Diffuser material - polypropylene
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In addition to the subwoofer amplifier, there are also 4 separate amplifiers in the complex, two of which are made on a well-known microcircuit TDA7384, as a result, 8 channels of 40 watts each are designed to power the interior acoustics. The remaining two amplifiers are made on a chip TDA2005, I used these particular microcircuits for one reason - they are cheap and have good sound quality and output power. The total power of the installation (nominal) is 650 watts, the peak power reaches 750 watts, but it is difficult to overclock to peak power, since the power supply does not allow this. Of course, 12 volts of a car is not enough to power a subwoofer amplifier, so a voltage converter is used.
Voltage transformer- perhaps the most difficult part of the whole structure, so let's consider it in a little more detail. Of particular difficulty is the winding of the transformer. The ferrite ring is almost never found on sale, so it was decided to use a transformer from a computer power supply, but since the frame of one transformer is clearly too small for winding, two identical transformers were used. First you need to find two identical ATX PSUs, solder large transformers, disassemble them and remove all factory windings. Ferrite halves are glued to each other, so they should be heated with a lighter for a minute, then the halves can be easily removed from the frame. After removing all the factory windings, you need to cut off one of the side walls of the frame, it is advisable to cut off the wall free from contacts. We do this with both frames. At the last stage, you need to attach the frames to each other as shown in the photographs. To do this, I used ordinary tape and electrical tape. Now you need to start winding.
The primary winding consists of 10 turns with a tap from the middle. The winding is wound immediately with 6 wires of 0.8 mm wire. First, we wind 5 turns along the entire length of the frame, then we isolate the winding with insulating tape and wind the remaining 5.
Now we wind the secondary winding. It is wound according to the same principle as the primary one, only it contains 40 turns with a tap from the middle. The winding is wound immediately with 3 cores of wire 0.6-0.8 mm, first one shoulder (along the entire length of the frame), then the other. After winding the first winding, we put insulation on top and wind the second half identically to the first. At the end, the wires are stripped of varnish and coated with tin. The last stage is to insert the halves of the core and fix it.
IMPORTANT! Do not allow a gap between the halves of the core, this will lead to an increase in the quiescent current and to abnormal operation of the transformer and the converter as a whole. You can fix the halves with tape, then fix with glue or epoxy. While the transformer is left alone and proceed to the assembly of the circuit. Such a transformer is capable of providing a bipolar voltage of 60-65 volts at the output, a rated power of 350 watts, a maximum of 500 watts, and a peak of 600-650 watts.
master oscillator rectangular pulses is made on a two-channel PWM controller TL494 tuned to a frequency of 50 kHz. The output signal of the microcircuit is amplified by a driver on low-power transistors, then it goes to the gates of the field switches. Driver transistors can be replaced with BC557 or domestic ones - KT3107 and other similar ones. The field effect transistors used are the IRF3205 series - this is an N - channel power transistor with a maximum power of 200 watts. 2 such transistors are used for each arm. In the rectifier part of the power supply, diodes of the KD213 series are used, although any diodes with a current of 10-20 amperes that can operate at frequencies of 100 kHz or more are suitable. You can use Schottky diodes from computer power supplies. To filter high-frequency interference, two identical chokes were used, they are wound on rings from computer power supplies and contain 8 turns of 3-wire wires 0.8 mm.
The main inductor is powered, wound on a ring from a computer power supply unit (the largest ring in diameter), it is wound with 4 strands of wire with a diameter of 0.8 mm, the number of turns is 13. The converter is powered when the remote control output is supplied stable plus, then the relay closes and the converter starts working. The relay must be used with a current of 40 amperes or more. Field keys are installed on small heat sinks from a computer PSU, they are screwed to the radiators through heat-conducting pads. The snubber resistor - 22 ohms should overheat a little, this is quite normal, so you need to use a resistor with a power of 2 watts. Now back to the transformer. It is necessary to phase the windings and solder it to the converter board. We first phase the primary winding. To do this, you need to solder the beginning of the first half of the winding (shoulder) to the end of the second or vice versa - the end of the first to the beginning of the second.
If the phasing is incorrect, the converter will either not work at all, or the field workers will fly off, so it is desirable to mark the beginning and end of the halves when winding. The secondary winding is phased exactly according to the same principle. Printed circuit board - in .
The finished converter should work without whistles and noises, at idle the heat sinks of transistors can overheat slightly, the quiescent current should not exceed 200 mA. After the completion of the PM, you can consider that the main work is done. You can already start assembling the LANZAR circuit, but more on that in the next article.
Discuss the article AMPLIFIER WITH YOUR HANDS - POWER SUPPLY
The circuit is relatively simple and is a bipolar stabilized power supply. The arms of the power supply are mirrored, so the circuit is absolutely symmetrical.
Specifications of the power supply:
Rated input voltage: ~18...22V
Maximum input voltage: ~28V (capacitor voltage limited)
Maximum input voltage (theoretically): ~70V (limited by the maximum voltage of the output transistors)
Output voltage range (at ~20V input): 12...16V
Rated output current (at output voltage 15V): 200mA
Maximum output current (at 15V output voltage): 300mA
Supply voltage ripple (at rated output current and voltage 15V): 1.8mV
Supply voltage ripple (at maximum output current and voltage 15V): 3.3mV
This power supply can be used to power preamplifiers. The PSU provides a fairly low level of supply voltage ripple, with a fairly large (for preamplifiers) current.
As analogues of the MPSA42/92 transistors, you can use the KSP42/92 or 2N5551/5401 transistors. Don't forget to check the pinout.
Transistors BD139 / BD140 can be replaced with BD135 / 136 or other transistors with similar parameters, again, do not forget about the pinout.
Transistors VT1 and VT6 must be installed on a heat sink, a place for which is provided on the printed circuit board.
As Zener diodes VD2 and VD3, you can use any Zener diodes for a voltage of 12V.
It often happens that a radio amateur has a transformer, but with only one winding, but it is necessary to get a bipolar voltage at the output. It is for these purposes that the following scheme can be applied:
The scheme is distinguished by its simplicity and versatility. AC voltage can be applied to the input of the circuit in a wide range, limited only by the allowable voltage of the bridge diodes, the allowable voltage of the supply capacitors and the voltage of the CE transistors. The output voltage of each of the arms will be equal to half of the total supply voltage or (Uin * 1.41) / 2, for example: with an input AC voltage of 20V, the output voltage of one arm will be (20 * 1.41) / 2 \u003d 14V.
As transistors VT1 and VT2, you can use ANY complementary transistors, you should just not forget about the pinout. Good replacements might be MPSA42/92, KSP42/92, BC546/556, KT3102/3107 and so on. It should also be taken into account when replacing transistors with analogues, their maximum allowable voltage of the CE, it must be at least the output voltage of the arm.
In my practice, to power the UMZCH, I like to use transformers with 4 identical secondary windings to power the UMZCH, in particular, the TA196, TA163 and similar transformers. When using such transformers, it is convenient to use not a bridge, but a two-half-wave half-bridge circuit as a rectifier. The diagram of the power supply itself is shown below:
For this circuit, you can use not only transformers of the TA, TAN, CCI, TN series, but also any other transformers with 4 windings of the same voltage.
Based on the TA196 transformer or other transformers with 4 secondary windings, the following circuit can be organized:
A voltage of +/-40V (or another, depending on the voltage on the windings of your transformer) is used to power the power amplifier. The +/-15V rails can be used to power the preamp and input buffer. The +12V bus can be used for auxiliary needs, for example: for powering a fan, protection, or other devices that are not demanding on the quality of the power supply.
As a zener diode 1N4742, you can use any other for a voltage of 12V, instead of 1N4728 - for a voltage of 3.3V.
Instead of BD139 / 140 transistors, you can use any other complementary pair of medium power transistors for a current of 1-2A. Transistors VT1, VT2 and VT3 must be installed on the radiator.
The numbering of the conclusions corresponds to the numbering of the conclusions of the TA196 transformer and similar ones.
Photos of some of the presented power supplies.
All power supplies come with 100% tested printed circuit boards.
List of radio elements
| Designation | Type | Denomination | Quantity | Note | Shop | My notepad | |
|---|---|---|---|---|---|---|---|
| Diagram 1: Low Power Regulated Power Supply for Preamplifiers | |||||||
| VT1 | bipolar transistor | BD139 | 1 | Analog:BD135 | To notepad | ||
| VT6 | bipolar transistor | BD140 | 1 | Analog:BD136 | To notepad | ||
| VT2, VT3 | bipolar transistor | MPSA42 | 2 | Analog:KSP42, 2N5551 | To notepad | ||
| VDS1, VDS2 | rectifier diode | 1N4007 | 8 | To notepad | |||
| VT4, VT5 | bipolar transistor | MPSA92 | 2 | Analog:KSP92, 2N5401 | To notepad | ||
| VD1, VD4 | rectifier diode | 1N4148 | 2 | To notepad | |||
| VD2, VD3 | zener diode | 1N4742 | 2 | Any 12V zener diodes | To notepad | ||
| C1, C6, C15, C18 | Capacitor | 2.2uF | 4 | Ceramics | To notepad | ||
| C2-C5, C16, C17, C19, C20 | Capacitor | 1000uF | 8 | Electrolyte 50V | To notepad | ||
| C7, C9, C21, C23 | Capacitor | 100uF | 4 | Electrolyte 50V | To notepad | ||
| C8, C10, C22, C24 | Capacitor | 100 nF | 4 | Ceramics | To notepad | ||
| C11, C14 | Capacitor | 220 pF | 2 | Ceramics | To notepad | ||
| C12, C13 | Capacitor | 1 uF | 2 | 50V electrolyte or ceramic | To notepad | ||
| R1, R12 | Resistor | 10 ohm | 2 | To notepad | |||
| R2, R10 | Resistor | 10 kOhm | 2 | To notepad | |||
| R3, R11 | Resistor | 33 kOhm | 2 | To notepad | |||
| R4, R9 | Resistor | 4.7 kOhm | 2 | To notepad | |||
| R5, R7 | Resistor | 18 kOhm | 2 | To notepad | |||
| R6, R8 | Resistor | 1 kOhm | 2 | To notepad | |||
| Scheme 2: Low-power power supply with unipolar to bipolar voltage conversion | |||||||
| VT1 | bipolar transistor | 2N5551 | 1 | Analog:KSP42, MPSA42 | To notepad | ||
| VT2 | bipolar transistor | 2N5401 | 1 | Analog:KSP92, MPSA92 | To notepad | ||
| VDS1 | rectifier diode | 1N4007 | 4 | To notepad | |||
| VD1, VD2 | rectifier diode | 1N4148 | 2 | To notepad | |||
| C1-C4, C6, C7 | Capacitor | 2200uF | 6 | Operating voltage depending on the input | To notepad | ||
| C5, C8 | Capacitor | 100 nF | 2 | To notepad | |||
| R1, R2 | Resistor | 3.3 kOhm | 2 | To notepad | |||
| Scheme 3: Powerful bipolar power supply with half-bridge rectification | |||||||
| VD1-VD4 | rectifier diode | FR607 | 4 | To notepad | |||
| C1, C5 | Capacitor | 15000uF | 2 | Electrolyte 50V | To notepad | ||
| C2, C3, C7, C8 | Capacitor | 1000uF | 4 | Electrolyte 50V | To notepad | ||
| C4, C6 | Capacitor | 1 uF | 2 | To notepad | |||
| F1-F4 | Fuse | 5 A | 4 | To notepad | |||
| Diagram 4: Powerful half-bridge rectified power supply | |||||||
| VT1, VT3 | bipolar transistor | BD139 | 2 | Analog:BD135 | To notepad | ||
| VT2 | bipolar transistor | BD140 | 1 | Analog:BD136 | |||
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