DIY triac voltage regulator circuit. Making a power regulator on a triac with your own hands

(Option 1)

In triac power regulators operating on the principle of passing a certain number of current half-cycles per unit time through the load, the condition of evenness of their number must be met. In many well-known amateur radio (and not only) designs it is violated. Readers are offered a regulator that is free from this drawback. Its diagram is shown in rice. 1.

There is a power supply unit, an adjustable duty cycle pulse generator and a pulse shaper that controls the triac. The power supply unit is made according to the classical scheme: current-limiting resistor R2 and capacitor C1, rectifier on diodes VD3, VD4, zener diode VD5, smoothing capacitor SZ. The pulse frequency of the generator, assembled on elements DD1.1, DD1.2 and DD1.4, depends on the capacitance of capacitor C2 and the resistance between the extreme terminals of variable resistor R1. The same resistor regulates the duty cycle of the pulses. Element DD1.3 serves as a pulse shaper with the frequency of the mains voltage supplied to its output 1 through a divider of resistors R3 and R4, and each pulse begins near the transition of the instantaneous value of the mains voltage through zero. From the output of element DD1.3, these pulses through limiting resistors R5 and R6 arrive at the bases of transistors VT1, VT2. The control pulses amplified by the transistors come through the separating capacitor C4 to the control electrode of the triac VS1. Here their polarity corresponds to the sign of the mains voltage applied at that moment to the pin. 2 triacs. Due to the fact that elements DD1.1 and DD1.2, DD1.3 and DD1.4 form two triggers, the level at the output of element DD1.4, connected to pin 2 of element DD1.3, changes to the opposite only in the negative half-cycle of the mains voltage . Suppose the trigger on elements DD1.3, DD1.4 is in a state with a low level at the output of element DD1.3 and a high level at the output of element DD1.4. To change this state, it is necessary that the high level at the output of element DD1.2, connected to pin 6 of element DD1.4, becomes low. And this can only happen in the negative half-cycle of the mains voltage supplied to pin 13 of element DD1.1, regardless of the moment the high level is set at pin 8 of element DD1.2. The formation of a control pulse begins with the arrival of a positive half-cycle of the mains voltage at pin 1 of element DD1.3. At some point, as a result of recharging capacitor C2, the high level at pin 8 of element DD1.2 will change to low, which will set a high voltage level at the output of the element. Now the high level at the output of element DD1.4 can also change to low, but only during the negative half-cycle of the voltage supplied to pin 1 of element DD1.3. Consequently, the operating cycle of the control pulse shaper will end at the end of the negative half-cycle of the mains voltage, and the total number of half-cycles of the voltage applied to the load will be even. The main part of the device parts is mounted on a board with single-sided printing, the drawing of which is shown in rice. 2.

Diodes VD1 and VD2 are soldered directly to the terminals of variable resistor R1, and resistor R7 is soldered to the terminals of triac VS1. The triac is equipped with a factory-made ribbed heat sink with a heat-removing surface area of about 400 cm2. Fixed resistors MLT were used, variable resistor R1 - SPZ-4aM. It can be replaced by another of the same or greater resistance. The values of resistors R3 and R4 must be the same. Capacitors C1, C2 - K73-17. If increased reliability is required, then the oxide capacitor C4 can be replaced with a film capacitor, for example, K73-17 2.2...4.7 μF at 63 V, but the size of the printed circuit board will have to be increased.
Instead of KD521A diodes, other low-power silicon ones will also be suitable, and the D814V zener diode will replace any more modern one with a stabilization voltage of 9 V. Replacing transistors KT3102V, KT3107G - other low-power silicon ones of the corresponding structure. If the amplitude of the current pulses opening the triac VS1 is insufficient, the resistance of resistors R5 and R6 cannot be reduced. It is better to select transistors with the highest possible current transfer coefficient at a voltage between the collector and emitter of 1 V. For VT1 it should be 150...250, for VT2 - 250...270. Upon completion of installation, you can connect a load with a resistance of 50...100 Ohms to the regulator and connect it to the network. Connect a 300...600 V DC voltmeter in parallel to the load. If the triac opens steadily in both half-cycles of the mains voltage, the voltmeter needle does not deviate from zero at all or fluctuates slightly around it. If the voltmeter needle deviates only in one direction, it means that the triac opens only in half-cycles of the same sign. The direction of deflection of the arrow corresponds to the polarity of the voltage applied to the triac at which it remains closed. Usually, correct operation of the triac can be achieved by installing transistor VT2 with a high current transfer coefficient.

Triac power regulator.
(Option 2)

The proposed triac power regulator (see figure) can be used to regulate the active power of heating devices (soldering iron, electric stove, stove, etc.). It is not recommended to use it to change the brightness of lighting fixtures, because they will flash heavily. A special feature of the regulator is the switching of the triac when the mains voltage crosses zero, so it does not create network interference. The power is regulated by changing the number of half-cycles of the mains voltage supplied to the load.

The synchronizer is made on the basis of the logical element EXCLUSIVE OR DD1.1. Its feature is the appearance of a high level (logical “1”) at the output when the input signals differ from each other, and a low level (“O”) when the input signals are identical. As a result of this, "G appears at the DD1.1 output only when the mains voltage crosses zero. The rectangular pulse generator with adjustable duty cycle is made on logic elements DD1.2 and DD1.3. Connecting one of the inputs of these elements to power turns them into inverters The result is a rectangular pulse generator. The pulse frequency is approximately 2 Hz, and their duration is changed by resistor R5.

On resistor R6 and diodes VD5. VD6 has a 2I matching circuit. A high level at its output appears only when two “1”s coincide (the synchronization pulse and the pulse from the generator). As a result, bursts of synchronization pulses appear at output 11 DD1.4. Element DD1.4 is a pulse repeater, for which one of its inputs is connected to a common bus.
Transistor VT1 contains a control pulse shaper. Packs of short pulses from its emitter, synchronized with the beginning of half-cycles of the mains voltage, arrive at the control transition of triac VS1 and open it. Current flows through RH.

The triac power regulator is powered through the R1-C1-VD2 chain. Zener diode VD1 limits the supply voltage to 15 V. Positive pulses from zener diode VD1 through diode VD2 charge capacitor SZ.
With high regulated power, triac VS1 must be installed on a radiator. Then a triac of the KU208G type allows you to switch power up to 1 kW. The dimensions of the radiator can be approximately estimated from the calculation that for 1 W of dissipated power, about 10 cm2 of the effective surface of the radiator is required (the triac body itself dissipates 10 W of power). For more power, a more powerful triac is needed, for example, TS2-25-6. It allows you to switch a current of 25 A. The triac is selected with a permissible reverse voltage of at least 600 V. It is advisable to protect the triac with a varistor connected in parallel, for example, CH-1-1-560. Diodes VD2...VD6 can be used in any circuit, for example. KD522B or KD510A Zener diode - any low-power voltage of 14...15 V. D814D will do.

The triac power regulator is placed on a printed circuit board made of single-sided fiberglass with dimensions of 68x38 mm.

Simple power regulator.

Power regulator up to 1 kW (0%-100%).
The circuit has been assembled more than once and works without adjustment or other problems. Naturally, diodes and a thyristor for a radiator with a power of more than 300 watts. If less, then the housings of the parts themselves are enough for cooling.
Initially, the circuit used transistors such as MP38 and MP41.

The scheme proposed below will reduce the power of any heating electrical appliance. The circuit is quite simple and accessible even to a novice radio amateur. To control a more powerful load, thyristors must be placed on a radiator (150 cm2 or more). To eliminate interference created by the regulator, it is advisable to install a choke at the input.

On the parent circuit, a KU208G triac was installed, and I was not satisfied with it due to the low switching power. After some digging I found imported triacs BTA16-600. The maximum switching voltage of which is 600 volts at a current of 16A!!!
All resistors are MLT 0.125;
R4 - SP3-4aM;
The capacitor is made up of two (connected in parallel) 1 microfarad of 250 volts, type K73-17.
With the data indicated in the diagram, the following results were achieved: Voltage adjustment from 40 to mains voltage.

The regulator can be inserted into the standard heater housing.

The circuit is copied from the vacuum cleaner regulator board.

Marking on the condenser: 1j100
I tried to control a 2 kW heating element - I didn’t notice any blinking of the light in the same phase,
the voltage on the heating element is regulated smoothly and seemingly uniformly (proportional to the angle of rotation of the resistor).
Adjustable from 0 to 218 volts with a network voltage of 224-228 volts.

There are many models of soldering irons in stores - from cheap Chinese ones to expensive ones, with a built-in temperature controller; they even sell soldering stations.

Another thing is, is the same station needed if such work needs to be done once a year, or even less often? It's easier to buy an inexpensive soldering iron. And some people still have simple but reliable Soviet instruments at home. A soldering iron that is not equipped with additional functionality heats up as long as the plug is plugged in. And when turned off, it cools down quickly. An overheated soldering iron can ruin the work: it becomes impossible to solder anything firmly, the flux quickly evaporates, the tip oxidizes and the solder rolls off it. An insufficiently heated tool can even ruin the parts - due to the fact that the solder does not melt well, the soldering iron can be held close to the parts.

To make work more comfortable, you can assemble a power regulator with your own hands, which will limit the voltage and thereby prevent the soldering iron tip from overheating.

DIY soldering iron regulators. Overview of installation methods

Depending on the type and set of radio components, power regulators for a soldering iron can be of different sizes, with different functionality. You can assemble either a small simple device, in which heating is stopped and resumed by pressing a button, or a large one, with a digital indicator and program control.

Possible types of installation in the housing: plug, socket, station

Depending on the power and tasks, the regulator can be placed in several types of housing. The simplest and most convenient one is a fork. To do this, you can use a cell phone charger or the housing of any adapter. All that remains is to find the handle and place it in the wall of the case. If the soldering iron body allows it (there is enough space), you can place the board with the parts in it.

Such a power regulator is always with the soldering iron - it cannot be forgotten or lost

Another type of housing for simple regulators is a socket. It can be either single or a tee-extension. In the latter you can very conveniently place a handle with a scale.

The case is convenient for placing a board with parts

In place of one and sockets there is a switch handle with a scale

There may also be several options for installing a regulator with a voltage indicator. It all depends on the radio amateur’s intelligence and imagination. This can be either the obvious option - an extension cord with an indicator built into it, or original solutions.

The counter on the body gives accurate numbers for work where a strictly defined temperature is important

The board is secured inside with screws

You can even assemble something like a soldering station and install a soldering iron stand on it (it can be purchased separately). When installing, we must not forget about safety rules. The parts need to be insulated - for example, with heat shrink tubing.

Circuit options depending on the power limiter

The power regulator can be assembled according to different schemes. The main differences lie in the semiconductor part, the device that will regulate the flow of current. This could be a thyristor or triac. For more precise control of the operation of a thyristor or triac, you can add a microcontroller to the circuit.

You can make a simple regulator with a diode and a switch - in order to leave the soldering iron in working condition for some (possibly long) time, without allowing it to cool down or overheat. The remaining controls make it possible to set the temperature of the soldering iron tip more smoothly - to suit different needs. Assembling the device according to any of the schemes is done in a similar way. The photographs and videos provide examples of how you can assemble a power regulator for a soldering iron with your own hands. Based on them, you can make a device with the variations you personally need and according to your own design.

A kind of electronic key. Passes current in only one direction. Unlike a diode, a thyristor has 3 outputs - a control electrode, an anode and a cathode. The thyristor opens by applying a pulse to the electrode. It closes when the direction changes or the current flowing through it stops.

Thyristor, its main components and display on diagrams

Or a triac is a type of thyristor, but unlike this device, it is double-sided and conducts current in both directions. It is essentially two thyristors connected together.

Triac or triac. Main parts, principle of operation and method of display in diagrams. A1 and A2 - power electrodes, G - control gate

The power regulator circuit for a soldering iron, depending on its capabilities, includes the following radio components.

Serves to convert voltage into current and vice versa. Capacitor- the main role of this device is that it stops conducting current as soon as it is discharged. And it begins to conduct again - as the charge reaches the required value. In regulator circuits, the capacitor is used to turn off the thyristor. - semiconductor, an element that passes current in the forward direction and does not pass in the reverse direction. Subtype of diode - zener diode - used in devices for voltage stabilization. Microcontroller

- a microcircuit that provides electronic control of the device. There are varying degrees of difficulty.

Diodes do not conduct current in the opposite direction

This is how a diode is designated in diagrams

Zener diodes are used to stabilize voltage

The capacitor is mainly used to turn off the thyristor

Appearance of the resistor and method of display on the diagram

This type of regulator is the easiest to assemble, with the fewest parts. It can be collected without payment, by weight. The switch (button) closes the circuit - all voltage is supplied to the soldering iron, opens it - the voltage drops, and so does the temperature of the tip. The soldering iron remains heated - this method is good for standby mode. A rectifier diode rated for a current of 1 Ampere is suitable.

The easiest regulator to install

Assembling a two-stage regulator on weight

Prepare parts and tools: diode (1N4007), switch with button, cable with plug (this can be a soldering iron cable or an extension cord - if you are afraid of ruining the soldering iron), wires, flux, solder, soldering iron, knife.
Strip and then tin the wires.
Tin the diode. Solder the wires to the diode. Remove excess ends of the diode. Place heat-shrinkable tubes and apply heat. You can also use an electrically insulating tube - cambric. Prepare a cable with a plug in the place where it will be more convenient to mount the switch. Cut the insulation, cut one of the wires inside. Leave part of the insulation and the second wire intact. Strip the ends of the cut wire.
Place the diode inside the switch: the minus of the diode is towards the plug, the plus is towards the switch.
Twist the ends of the cut wire and the wires connected to the diode. The diode must be inside the gap. The wires can be soldered. Connect to terminals, tighten screws. Assemble the switch.

Regulator with switch and diode - step by step and clearly

Thyristor regulator

Regulator with power limiter - thyristor - allows you to smoothly set the soldering iron temperature from 50 to 100%. In order to expand this scale (from zero to 100%), you need to add a diode bridge to the circuit. The assembly of regulators on both a thyristor and a triac is done in a similar way. The method can be applied to any device of this type.

An example of mounting a thyristor regulator on a board

Assembling a thyristor (triac) regulator on a printed circuit board

Make a wiring diagram - outline a convenient location of all the parts on the board. If the board is purchased, the wiring diagram is included in the kit.
Prepare parts and tools: printed circuit board (it must be made in advance according to the diagram or purchased), radio components - see the specification for the diagram, wire cutters, knife, wires, flux, solder, soldering iron.
Place the parts on the board according to the wiring diagram.
Use wire cutters to cut off the excess ends of the parts.
Lubricate with flux and solder each part - first resistors with capacitors, then diodes, transistors, thyristor (triac), dinistor.
Prepare the housing for assembly.
Strip and tin the wires, solder them to the board according to the wiring diagram, and install the board into the case. Insulate the connection points of the wires.
Check the regulator - connect it to an incandescent lamp.
Assemble the device.

Circuit with low-power thyristor

A low-power thyristor is inexpensive and takes up little space. Its peculiarity is increased sensitivity. To control it, a variable resistor and capacitor are used. Suitable for devices with a power of no more than 40 W.

This regulator does not require additional cooling

Specification

Circuit with a powerful thyristor

The thyristor is controlled by two transistors. The power level is controlled by resistor R2. The regulator assembled according to this scheme is designed for a load of up to 100 W.

The regulator is optimal for loads up to 100 W

Specification

Assembling a thyristor regulator according to the above diagram into a housing - visually

Assembly and testing of a thyristor regulator (review of parts, installation features)

Such a device makes it possible to adjust power from zero to 100%. The circuit uses a minimum of parts.

On the right is a voltage conversion diagram

Specification

Triac regulator

Triac-based regulator circuit with a small number of radio components. Allows you to adjust power from zero to 100%. The capacitor and resistor will ensure the smooth operation of the triac - it will open even at low power.

An LED is used as an indicator in this power regulator.

Assembling a triac regulator according to the given diagram step by step

Triac regulator with diode bridge

The circuit of such a regulator is not very complicated. At the same time, the load power can be varied over a fairly wide range. With a power of more than 60 W, it is better to place a triac on a radiator. At lower power, cooling is not needed. The assembly method is the same as in the case of a conventional triac regulator.

Before installation, the assembled regulator can be checked with a multimeter. You only need to check with a soldering iron connected., that is, under load. We rotate the resistor knob - the voltage changes smoothly.

Regulators assembled according to some of the diagrams given here will already have indicator lights. They can be used to determine whether the device is working. For others, the simplest test is to connect an incandescent light bulb to the power regulator. The change in brightness will clearly reflect the level of the supplied voltage.

Regulators where the LED is in series with a resistor (as in the circuit with a low-power thyristor) can be adjusted. If the indicator does not light, you need to select the resistor value - take one with lower resistance until the brightness is acceptable. You cannot achieve too much brightness - the indicator will burn out.

As a rule, adjustment is not required if the circuit is correctly assembled. With the power of a conventional soldering iron (up to 100 W, average power - 40 W), none of the regulators assembled according to the above diagrams require additional cooling. If the soldering iron is very powerful (from 100 W), then a thyristor or triac must be installed on the radiator to avoid overheating.

The heatsink will prevent the device from overheating

You can assemble a power regulator for a soldering iron with your own hands, focusing on your own capabilities and needs. There are many options for regulator circuits with different power limiters and different controls. Here are some of the simplest ones. A short overview of the housings in which parts can be mounted will help you choose the format of the device.

A selection of circuits and a description of the operation of a power regulator using triacs and more. Triac power regulator circuits are well suited for extending the life of incandescent lamps and for adjusting their brightness. Or for powering non-standard equipment, for example, 110 volts.

The figure shows a circuit of a triac power regulator, which can be changed by changing the total number of network half-cycles passed by the triac over a certain time interval. The elements of the DD1.1.DD1.3 microcircuit are made with an oscillation period of about 15-25 network half-cycles.

The duty cycle of the pulses is regulated by resistor R3. Transistor VT1 together with diodes VD5-VD8 is designed to bind the moment the triac is turned on during the transition of the mains voltage through zero. Basically, this transistor is open, respectively, a “1” is sent to the input DD1.4 and transistor VT2 with triac VS1 are closed. At the moment of crossing zero, transistor VT1 closes and opens almost immediately. In this case, if the output DD1.3 was 1, then the state of the elements DD1.1.DD1.6 will not change, and if the output DD1.3 was “zero”, then the elements DD1.4.DD1.6 will generate a short pulse, which will be amplified by transistor VT2 and open the triac.

As long as there is a logical zero at the output of the generator, the process will proceed cyclically after each transition of the mains voltage through the zero point.

The basis of the circuit is a foreign triac mac97a8, which allows you to switch high-power connected loads, and to regulate it I used an old Soviet variable resistor, and used a regular LED as an indication.

The triac power regulator uses the principle of phase control. The operation of the power regulator circuit is based on changing the moment the triac is turned on relative to the transition of the mains voltage through zero. At the initial moment of the positive half-cycle, the triac is in the closed state. As the mains voltage increases, capacitor C1 is charged through a divider.

The increasing voltage on the capacitor is shifted in phase from the mains voltage by an amount depending on the total resistance of both resistors and the capacitance of the capacitor. The capacitor is charged until the voltage across it reaches the “breakdown” level of the dinistor, approximately 32 V.

At the moment the dinistor opens, the triac will also open, and a current will flow through the load connected to the output, depending on the total resistance of the open triac and the load. The triac will be open until the end of the half-cycle. With resistor VR1 we set the opening voltage of the dinistor and triac, thereby regulating the power. At the time of the negative half-cycle, the circuit operation algorithm is similar.

Option of the circuit with minor modifications for 3.5 kW

The controller circuit is simple, the load power at the output of the device is 3.5 kW. With this homemade amateur radio you can adjust lighting, heating elements and much more. The only significant drawback of this circuit is that you cannot connect an inductive load to it under any circumstances, because the triac will burn out!

Radio components used in the design: Triac T1 - BTB16-600BW or similar (KU 208 or VTA, VT). Dinistor T - type DB3 or DB4. Capacitor 0.1 µF ceramic.

Resistance R2 510 Ohm limits the maximum volts on the capacitor to 0.1 μF; if you put the regulator slider in the 0 Ohm position, the circuit resistance will be about 510 Ohms. The capacitance is charged through resistors R2 510 Ohm and variable resistance R1 420 kOhm, after U on the capacitor reaches the opening level of dinistor DB3, the latter will generate a pulse that unlocks the triac, after which, with further passage of the sinusoid, the triac is locked. The opening and closing frequency of T1 depends on the level of U on the 0.1 μF capacitor, which depends on the resistance of the variable resistor. That is, by interrupting the current (at a high frequency) the circuit thereby regulates the output power.

With each positive half-wave of the input alternating voltage, capacitance C1 is charged through a chain of resistors R3, R4, when the voltage on capacitor C1 becomes equal to the opening voltage of dinistor VD7, its breakdown will occur and the capacitance will be discharged through the diode bridge VD1-VD4, as well as resistance R1 and control electrode VS1. To open the triac, an electrical chain of diodes VD5, VD6, capacitor C2 and resistance R5 is used.

It is necessary to select the value of resistor R2 so that at both half-waves of the mains voltage, the regulator triac operates reliably, and it is also necessary to select the values of resistances R3 and R4 so that when the variable resistance knob R4 is rotated, the voltage on the load smoothly changes from minimum to maximum values. Instead of the TC 2-80 triac, you can use TC2-50 or TC2-25, although there will be a slight loss in the permissible power in the load.

KU208G, TS106-10-4, TS 112-10-4 and their analogs were used as a triac. At the moment when the triac is closed, capacitor C1 is charged through the connected load and resistors R1 and R2. The charging speed is changed by resistor R2, resistor R1 is designed to limit the maximum value of the charge current

When the threshold voltage value is reached on the capacitor plates, the switch opens, capacitor C1 is quickly discharged to the control electrode and switches the triac from the closed state to the open state; in the open state, the triac bypasses the circuit R1, R2, C1. At the moment the mains voltage passes through zero, the triac closes, then capacitor C1 is charged again, but with a negative voltage.

Capacitor C1 from 0.1...1.0 µF. Resistor R2 1.0...0.1 MOhm. The triac is switched on by a positive current pulse to the control electrode with a positive voltage at the conventional anode terminal and by a negative current pulse to the control electrode with a negative voltage at the conventional cathode. Thus, the key element for the regulator must be bidirectional. You can use a bidirectional dinistor as a key.

Diodes D5-D6 are used to protect the thyristor from possible breakdown by reverse voltage. The transistor operates in avalanche breakdown mode. Its breakdown voltage is about 18-25 volts. If you don’t find P416B, then you can try to find a replacement for it.

The pulse transformer is wound on a ferrite ring with a diameter of 15 mm, grade N2000. The thyristor can be replaced with KU201

The circuit of this power regulator is similar to the circuits described above, only the interference suppression circuit C2, R3 is introduced, and the switch SW makes it possible to break the charging circuit of the control capacitor, which leads to instant locking of the triac and disconnecting the load.

C1, C2 - 0.1 MKF, R1-4k7, R2-2 mOhm, R3-220 Ohm, VR1-500 kOhm, DB3 - dinistor, BTA26-600B - triac, 1N4148/16 V - diode, any LED.

The regulator is used to regulate load power in circuits up to 2000 W, incandescent lamps, heating devices, soldering iron, asynchronous motors, car charger, and if you replace the triac with a more powerful one, it can be used in the current regulation circuit in welding transformers.

The principle of operation of this power regulator circuit is that the load receives a half-cycle of the mains voltage after a selected number of skipped half-cycles.

The diode bridge rectifies alternating voltage. Resistor R1 and zener diode VD2, together with the filter capacitor, form a 10 V power source to power the K561IE8 microcircuit and the KT315 transistor. The rectified positive half-cycles of the voltage passing through capacitor C1 are stabilized by the zener diode VD3 at a level of 10 V. Thus, pulses with a frequency of 100 Hz follow to the counting input C of the K561IE8 counter. If switch SA1 is connected to output 2, then a logical one level will be constantly present at the base of the transistor. Because the microcircuit reset pulse is very short and the counter manages to restart from the same pulse.

Pin 3 will be set to a logical one level. The thyristor will be open. All power will be released at the load. In all subsequent positions of SA1 at pin 3 of the counter, one pulse will pass through 2-9 pulses.

The K561IE8 chip is a decimal counter with a positional decoder at the output, so the logical one level will be periodic at all outputs. However, if the switch is installed on output 5 (pin 1), then counting will only occur up to 5. When the pulse passes through output 5, the microcircuit will be reset to zero. Counting will begin from zero, and a logical one level will appear at pin 3 for the duration of one half-cycle. During this time, the transistor and thyristor open, one half-cycle passes to the load. To make it clearer, I present vector diagrams of the circuit operation.

If you need to reduce the load power, you can add another counter chip by connecting pin 12 of the previous chip to pin 14 of the next one. By installing another switch, you can adjust the power up to 99 missed pulses. Those. you can get about a hundredth of the total power.

The KR1182PM1 microcircuit has two thyristors and a control unit for them. The maximum input voltage of the KR1182PM1 microcircuit is about 270 Volts, and the maximum load can reach 150 Watts without the use of an external triac and up to 2000 W with the use, and also taking into account the fact that the triac will be installed on the radiator.

To reduce the level of external noise, capacitor C1 and inductor L1 are used, and capacitance C4 is required for smooth switching on of the load. The adjustment is carried out using resistance R3.

A selection of fairly simple regulator circuits for a soldering iron will make life easier for a radio amateur.

Combination consists in combining the convenience of using a digital regulator and the flexibility of adjusting a simple one.

The considered power regulator circuit works on the principle of changing the number of periods of the input alternating voltage going to the load. This means that the device cannot be used to adjust the brightness of incandescent lamps due to visible blinking. The circuit makes it possible to regulate power within eight preset values.

There are a huge number of classic thyristor and triac regulator circuits, but this regulator is made on a modern element base and, in addition, was phase-based, i.e. does not transmit the entire half-wave of the mains voltage, but only a certain part of it, thereby limiting the power, since the triac opens only at the required phase angle.

In almost any radio-electronic device, in most cases there is power adjustment. You don’t have to look far for examples: these are electric stoves, boilers, soldering stations, various motor rotation controllers in devices.

The Internet is full of ways to assemble a 220 V voltage regulator with your own hands. In most cases, these are circuits based on triacs or thyristors. The thyristor, unlike the triac, is a more common radio element, and circuits based on it are much more common. Let's look at different design options based on both semiconductor elements.

Triac, by and large, is a special case of a thyristor that passes current in both directions, provided that it is higher than the holding current. One of its disadvantages is its poor performance at high frequencies. Therefore, it is often used in low-frequency networks. It is quite suitable for building a power regulator based on a regular 220 V, 50 Hz network.

The voltage regulator on the triac is used in ordinary household appliances where adjustment is needed. Power regulator circuit on the triac looks like this.

Etc. 1 - fuse (selected depending on the required power).
R3 is a current-limiting resistor - it serves to ensure that when the potentiometer resistance is zero, the remaining elements do not burn out.
R2 is a potentiometer, a trimming resistor, which is used for adjustment.
C1 is the main capacitor, the charge of which unlocks the dinistor to a certain level, together with R2 and R3 it forms an RC circuit
VD3 is a dinistor, the opening of which controls the triac.
VD4 - triac - the main element that performs switching and, accordingly, adjustment.

The main work is assigned to the dinistor and triac. The mains voltage is supplied to an RC circuit in which a potentiometer is installed, which ultimately regulates the power. By adjusting the resistance, we change the charging time of the capacitor and thereby the threshold for turning on the dinistor, which, in turn, turns on the triac. An RC damper circuit connected in parallel with the triac serves to smooth out noise at the output, and also protects the triac from surges of high reverse voltage in case of a reactive load (motor or inductance).

The triac turns on when the current passing through the dynistor exceeds the holding current (reference parameter). It turns off accordingly when the current becomes less than the holding current. Conductivity in both directions allows for smoother adjustment than is possible, for example, with a single thyristor, while using a minimum of elements.

The power adjustment oscillogram is shown below. It shows that after turning on triac, the remaining half-wave is supplied to the load and when it reaches 0, when the holding current decreases to such an extent that the triac turns off. In the second “negative” half-cycle, the same process occurs, since the triac has conductivity in both directions.

Thyristor voltage

First, let's figure out how a thyristor differs from a triac. A thyristor contains 3 p-n junctions, and a triac contains 5 p-n junctions. Without going into details, in simple terms, a triac conducts in both directions, while a thyristor conducts only in one. Graphic designations of the elements are shown in the figure. This is clearly visible from the graphics..

The operating principle is absolutely the same. This is what power regulation is based on in any circuit. Let's look at several thyristor-based regulator circuits. The first is the simplest circuit, which basically repeats the triac circuit described above. The second and third - using logic, circuits that better dampen the interference created in the network by switching thyristors.

Simple scheme

A simple phase control circuit on a thyristor is presented below.

Its only difference from the triac circuit is that only the positive half-wave of the mains voltage is adjusted. The timing RC circuit, by adjusting the resistance value of the potentiometer, regulates the trigger value, thereby setting the output power supplied to the load. On the oscillogram it looks like this.

From the oscillogram it can be seen that power regulation occurs by limiting the voltage supplied to the load. Figuratively speaking, the regulation consists of limiting the flow of mains voltage to the output. By adjusting the charging time of the capacitor by changing the variable resistance (potentiometer). The higher the resistance, the longer it takes to charge the capacitor and the less power will be transferred to the load. The physics of the process is described in detail in the previous diagram. In this case, it is no different.

With logic based generator

The second option is more complicated. Due to the fact that switching processes on thyristors cause large noise in the network, this has a bad effect on elements installed on the load. Especially if the load is a complex device with fine settings and a large number of microcircuits.

This DIY implementation of a thyristor power regulator is suitable for active loads, for example, a soldering iron or any heating devices. There is a rectifier bridge at the input, so both waves of the mains voltage will be positive. Please note that with such a circuit, an additional +9 V DC voltage source will be needed to power the microcircuits. Due to the presence of a rectifier bridge, the oscillogram will look like this.

Both half-waves will now be positive due to the influence of the rectifier bridge. If for reactive loads (motors and other inductive loads) the presence of oppositely polar signals is preferable, then for active ones a positive power value is extremely important. The thyristor also turns off when the half-wave approaches zero, the holding current is supplied to a certain value and the thyristor is turned off.

Based on transistor KT117

The presence of an additional constant voltage source can cause difficulties; if it is not there, you will have to install an additional circuit. If you do not have an additional source, then you can use the following circuit, in which the signal generator to the control output of the thyristor is assembled using a conventional transistor. There are circuits based on generators built on complementary pairs, but they are more complex, and we will not consider them here.

In this circuit, the generator is built on a dual-base transistor KT117, which, when used in this way, will generate control pulses with a frequency set by trimming resistor R6. The diagram also includes an indication system based on the HL1 LED.

VD1-VD4 is a diode bridge that rectifies both half-waves and allows for smoother power adjustment.
EL1 - incandescent lamp - is represented as a load, but it can be any other device.
FU1 is a fuse, in this case it is 10 A.
R3, R4 - current-limiting resistors - are needed so as not to burn the control circuit.
VD5, VD6 - zener diodes - perform the role of stabilizing the voltage at a certain level at the emitter of the transistor.
VT1 - transistor KT117 - must be installed with exactly this location of base No. 1 and base No. 2, otherwise the circuit will not work.
R6 is a tuning resistor that determines the moment when a pulse arrives at the control output of the thyristor.
VS1 - thyristor - element that provides switching.
C2 is a timing capacitor that determines the period of appearance of the control signal.

The remaining elements play a minor role and mainly serve to limit current and smooth out pulses. HL1 provides an indication and signals only that the device is connected to the network and is energized.