Triac controller for inductive loads. Thyristor voltage regulator for transformer. Feedback in triac control circuits

Triac power regulator

The triac power regulator is designed to adjust the power of heating and lighting devices whose power does not exceed 1000 watts.

Specifications:
Working voltage; 160-300V
Power adjustment range 10-90%
Load current: up to 5 A

The device consists of a triac and a timing chain. The principle of power adjustment is to change the duration of the open state of the triac (Figure 1). The more time the triac is open, the more power is given to the load. And since the triac turns off at the moment when the current flowing through the triac is zero, then we will set the duration of the triac opening within half the period.

At the beginning of the positive half-cycle, the triac is closed. As the mains voltage increases, the capacitor C1 is charged through the divider R1, R2. The charge of the capacitor continues until the voltage across it reaches the "breakdown" threshold of the dinistor (about 32 V). The dinistor will close the circuit Dl, Cl, D3 and open the triac U1. The triac remains open until the end of the half cycle. The capacitor charging time is set by the chain parameters R1, R2, C1. With resistor R2, we set the charging time of the capacitor, and, accordingly, the moment of opening the dinistor and triac. Those. This resistor controls the power. Under the action of a negative half-wave, the principle of operation is similar. The LED light indicates the operating mode of the power controller.

Used radio elements:
R1 - 3.9...10K
R2-500K
C1 - 0.22uF
D1-1N4148
D2 - LED
D3-DB4
U1-BT06-600
P1,P2 terminal blocks
R3 - 22K 2W
C2 - 0.22uF 400V

A properly assembled setup does not require.

When using a load with a power of more than 300 W, the triac must be installed on a radiator with a surface area of ​​at least 20 cm 2
A handle made of insulated material must be installed on the variable resistor.

When the circuit is supplemented with only two elements (marked in red on the diagram), it becomes possible to control the inductive load. Those. you can connect a transformer to the output of the triac power controller.

ATTENTION! The device is not galvanically isolated from the mains! It is forbidden to touch the elements of the included circuit!

Watch the training video on the topic "Triac power controller"

The thyristor charging unit by Krasimir Rilchev is intended for charging the batteries of trucks and tractors. It provides a smoothly adjustable (by resistor RP1) charging current up to 30 A. The principle of regulation is phase-pulse based on thyristors, which provides maximum efficiency, minimum power dissipation and does not require powerful rectifier diodes. The network transformer is made on a magnetic circuit with a cross section of 40 cm2, the primary winding contains 280 turns of PEL-1.6, the secondary 2x28 turns of PEL-3.0. The thyristors are mounted on 120x120 mm radiators. ...

For the scheme "SIMPLE TEMPERATURE CONTROL OF THE SOLDERING TIP"

Consumer Electronics 3. This circuit is not my own design. I saw her for the first time in Radio magazine. I think it will interest many radio amateurs with its simplicity. The device allows you to adjust the power of the soldering iron from half to maximum. With the elements indicated in the diagram, the power loads should not exceed 50 W, but within an hour the circuit can transfer a load of 100 W without any special consequences. The regulator circuit is shown in the figure. If the VD2 thyristor is replaced by KU201, and the VD1 diode by KD203V, the connected power can be significantly increased. The output power is minimal in the extreme left (according to the diagram) position of the R2 engine. In my version, it is mounted in a table lamp stand using the hinged mounting method. At the same time, one network outlet is saved, which, as you know, is always in short supply. This one has been working for me for 14 years without any complaints. Literature 1. Radio, 1975, N6, C.53....

For the scheme "POWER REGULATOR WITH FEEDBACK"

For the scheme "VOLTAGE CONVERTER PN-32"

Power supply VOLTAGE CONVERTER PN-32(S) RINTELsay Oleg, (RA3XBJ). The converter is designed to power equipment with a rated voltage of 12 V (SV radio stations, radio tape recorders, TVs, etc.) from the on-board network of cars with a voltage of 24 V. Maximum current loads converter up to 3A for a short time and 2-2.5 A for a long time (determined by the area of ​​\u200b\u200bthe radiator of the output transistor). Efficiency 75-90% depending on the load current. The converter circuit does not contain scarce parts. The inductor is wound on a ferrite ring with a diameter of 32 mm and has 50 turns of PETV-0.63 wire. Converter dimensions 65x90x40 mm. Questions on the design can be asked to the author [email protected]

Power supply "SOFT" LOAD IN THE MAINS MAINS When connecting and disconnecting loads interference often occurs in the electrical network, which disrupts the normal operation of sensitive electronic devices and electrical systems. The device, the scheme of which is shown in Fig. 1, realizes "soft" connection and disconnection of the load. \u003d SOFT LOAD IN THE ELECTRICAL NETWORKPuc.1 When the contacts of the switch SA1 are closed during the charging of the capacitor C1 (through the resistor R1), the transistor VT1 gradually opens and the collector current gradually increases to a value determined by the ratio of the resistances of the resistors R1 and R2. Accordingly, the current in the load also gradually increases. When turned off, the capacitor discharges through resistor R2 and the base-emitter junction of the transistor. The current gradually decreases to zero. With the values ​​\u200b\u200bof the elements and power of 200 W indicated on the diagram, the duration of the on-time process is 0.1 s, off - 0.5 s. T160 current regulator circuit The voltage losses in this device are relatively small, they are determined by the sum of the direct drop on the two diodes and the collector-emitter section of the operating transistor, which is approximately: Uce (B) \u003d 0.7 + R1 * In / h21e Depending on the current loads and the current transfer coefficient of the base of the transistor, resistor R) should be selected in such a way that the voltage drop across the transistor and the power dissipation on it would be maintained at an acceptable level in the on state. =SOFT LOAD IN THE POWER MAINSPuc.2In the device variant shown in fig. 2, armor against overloads and short circuits is provided. When the current exceeds the set value, the drop ...

For the scheme "Load connection indicator"

Looking for a light switch or an outlet in the dark is not a pleasant thing. Household lighting switches appeared on sale, equipped with indicators that highlight their location. By slightly improving the circuit, such an indicator can be turned into a load connection indicator. Connection indicator loads(IPN) is a device built into the socket and indicating the presence of contact between the inserted mains plug from any household appliance and the socket. The indicator is especially convenient if the connected devices do not have their own network indicator. The PSU is also useful for electronic products that have power indicators located in the secondary power circuit, as it allows you to check their input circuits. The PPI consists of: - current sensor loads on diodes VD2...VD6; - L-shaped filter R1-C1; - key field effect transistor VT1; - an indication unit on the elements VD9, VD10, R2, HL1. If no load is connected to the XS1 socket, then no current flows through the diodes VD1 ... VD6, the storage capacitor C1 is discharged and the field effect transistor VT1 is closed. Power regulator on tc122 25 The drain current VT1 is zero, the HL1 indicator is off. When connected loads to socket XS1 current loads flows through the opposite-parallel connected diode VD1 and a chain of diodes VD2...VD6. Negative half-waves of the mains voltage pass through VD1. and positive - through VD2.. .VD6. The voltage drop across the diodes VD2 ... VD6 through the resistor R1 is fed to the storage capacitor C1 and charges it to a value exceeding the cutoff voltage of the field-effect transistor VT1. Transistor VT1 opens, and current flows through its source-drain channel, resistor R2, LED HL1 and diode VD9. LED HL1 dazzlingly glows, signaling the connection of the load. Resistor R2 is current-limiting, diode VD9 prohibits the flow of current through the load during reverse half-cycles of the mains voltage. Diode VD10 protects HL1 from reverse voltage....

For the scheme "Simple power regulator"

The inductive load in the power regulator circuit imposes strict requirements on the triac management circuits - the management system synchronization must be carried out directly from the mains, the signal must have a duration equal to the triac conduction interval. The figure shows a diagram of a regulator that meets these requirements, which uses a combination of a dinistor and a triac. The time constant (R4 + R5) C3 determines the opening delay angle of the dinistor VS1 and hence the triac VS2. Moving the slider of the variable resistor R5 regulates the power consumed by the load. Capacitor C2 and resistor R2 are used to synchronize and maintain the duration of the management signal. Capacitor C3 is recharged from C2 after switching, since at the end of each half cycle it has a reverse polarity voltage. To protect against interference created by the regulator, two Filters R1C1 are introduced - into the power circuit and R7C4 - into the load circuit. To establish the device, you need to set the resistor R5 to the position of maximum resistance and set the minimum power to the load with the resistor R3 Capacitors C1 and C4 of the K40P-2B type for 400 V Capacitors C2 and SZ of the K73-17 type for 250 V designed for a current of at least 5 A. VF Yakovlev, Shostka, Sumy region. ...

For "Telephone line holding device" scheme

Telephony Telephone line holding device The proposed device performs the function of holding a telephone line ("HOLD"), which allows you to put the handset on the hook during a conversation and go to a parallel telephone set. The device does not overload the telephone line (TL) and does not interfere with it. At the time of the trigger, the caller hears a background music. The diagram of the telephone line holding device is shown in the figure. The rectifier bridge on diodes VD1-VD4 provides the necessary polarity of the power supply of the device, regardless of the polarity of its connection to the TL. The SF1 switch is connected to the lever of the telephone set (TA) and closes when the handset is picked up (ie, it blocks the SB1 button when the handset is on-hook). If you need to switch to a parallel SLT during a conversation, press the SB1 button for a short time. In this case, relay K1 is activated (contacts K1.1 close, and contacts K1.2 open), an equivalent is connected to the TL loads(circuit R1R2K1) and the TA from which the conversation was conducted is turned off. T160 current regulator circuit Now you can put the handset on the lever and go to the parallel SLT. The voltage drop on the equivalent is 17 V. When the tube is picked up on the parallel SLT, the voltage in the TL drops to 10 V, relay K1 turns off and the equivalent is disconnected from the TL. Transistor VT1 must have a transfer coefficient of at least 100, while the amplitude of the audio frequency AC voltage output in TL reaches 40 mV. As a musical synthesizer (DD1), a UMC8 chip was used, in which two melodies and an alarm signal are "hardwired". Therefore, pin 6 ("melody selection") is connected to pin 5. In this case, the first melody is played once, and then the second indefinitely. As SF1 m...

For the circuit "STABLE CURRENT GENERATOR"

For a radio amateur-designer STABLE CURRENT GENERATOR It is customary to call devices stable current generators. whose output current is practically independent of the load resistance. It can be used, for example, in ohmmeters with a linear scale. On fig. 1 shows a schematic diagram of a stable current generator based on two silicon transistors. The value of the collector current of the transistor V2 is determined by the ratio Ik \u003d 0.66 / R2.Puc.1 For example, with R2 equal to 2.2 k0m. the collector current of the transistor V2 will be equal to 0.3 mA and remains almost constant when the resistance of the resistor Rx changes from 0 to 30 k0m. If necessary, the value of the direct current can be increased to 3 mA, for this the resistance of the resistor R2 must be reduced to 180 ohms. A further increase in current while maintaining high stability of its value both with a change in load and with an increase in temperature can only be possible when using a three-transistor generator shown in Fig. 2. In this case, transistors V2 and V3 should be of medium power, and the voltage of the second power source should be 2 ... 3 times the supply voltage of transistors V1, V2. The resistance of the resistor R3 is calculated using the above formula, but is additionally adjusted to take into account the variation in the characteristics of the transistors. Puc.2 "Elektrotehnicar" (SFRY), 1976, N 7-8 Editorial. Transistors BC 108 can be replaced by KT315G. VS107 -KT312B, BD137 - KT602B or KT605B, 2N3055 - KT803A....

For the circuit "TRANSISTOR UMZCH ON THE WAY TO PERFECTION"

AUDIO technique TRANSISTOR UMZCH ON THE WAY TO PERFECTION A. PETROV, Mogilev. Usually, considering the operation of UMZCH, it is assumed that its load is purely active. However, a loudspeaker, and even with smoothing filters, is a complex complex load. When operating on a complex load, the resulting phase shift between voltage and current at the output of the amplifier leads to the fact that with sinusoidal input signals, the load straight line turns into an ellipse. Operating point positions (load curve) for reactive loads on the output characteristics of a triode and a transistor when amplifying a harmonic signal are shown in Fig. 1 and 2, respectively. As can be seen from Fig. 1, the output characteristics of a triode are almost ideal for a complex load, which is the AC. A favorable range of harmonics (not higher than the fifth) and high linearity largely determine the "softness" of the sound of tube amplifiers. Ham radio converter circuits At the same time, a single-ended transistor amplifier is completely unsuitable for working on a loudspeaker, because the line enters, on the one hand, into the region of limitation in terms of the allowable power dissipation on the collector (shaded area, above the hyperbola), on the other hand, into nonlinear regions at small Uke. The transverse size of the ellipse of the load curve depends on inductive component of the load, and the longitudinal - from the active. When amplifying impulse signals, for example, the "meander" type, the line loads is a parallelogram, which further exacerbates the situation. The amplitude of the voltage jump at the moment of switching (due to self-induction EMF) depends on the ratio of the time constant of the signal To to the time constant loads T=L/R...

A selection of circuits and a description of the operation of the power regulator on triacs and not only. Triac power control circuits are well suited for extending the life of incandescent lamps and for adjusting their brightness. Or for powering non-standard equipment, for example, at 110 volts.

The figure shows a circuit of a triac power controller, which can be changed by changing the total number of network half-cycles skipped by the triac for a certain time interval. On the elements of the DD1.1.DD1.3 chip, the oscillation period of which is about 15-25 network half-cycles.

The duty cycle of the pulses is regulated by the 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, "1" is supplied to the input DD1.4 and the transistor VT2 with the triac VS1 is closed. At the moment of zero crossing, transistor VT1 closes and opens almost immediately. In this case, if the output of DD1.3 was 1, then the state of the elements DD1.1.DD1.6 will not change, and if the output of DD1.3 was "zero", then the elements DD1.4.DD1.6 will generate a short pulse, which will be amplified by the transistor VT2 and open the triac.

As long as the generator output is a logical zero, the process will go 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 used an old Soviet variable resistor to adjust it, and used a regular LED as an indication.

The triac power controller uses the principle of phase control. The operation of the power regulator circuit is based on a change in 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. With increasing mains voltage, capacitor C1 is charged through the divider.

The increasing voltage on the capacitor is phase shifted from the mains 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 is opened, the triac will also open, 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. Resistor VR1 sets the opening voltage of the dinistor and triac, thereby adjusting the power. At the moment of action of the negative half-cycle, the algorithm of the circuit is similar.

Circuit variant with minor modifications for 3.5 kW

The regulator circuit is simple, the load power at the output of the device is 3.5 kW. With this DIY ham radio you can control lights, heating elements and more. The only significant drawback of this circuit is that it is impossible to connect an inductive load to it in any case, because the triac will burn out!

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

Resistance R2 510 Ohm limits the maximum volts on the capacitor to 0.1 uF, if you put the regulator slider in the 0 Ohm position, then the circuit resistance will be about 510 Ohms. The capacitance is charged through resistors R2 510Ω and variable resistance R1 420kΩ, after U on the capacitor reaches the opening level of the DB3 dinistor, the latter will generate a pulse that unlocks the triac, after which, with a further passage of the sinusoid, the triac is locked. The opening-closing frequency T1 depends on the level U on the 0.1uF 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 AC voltage, capacitance C1 is charged through a chain of resistors R3, R4, when the voltage across capacitor C1 becomes equal to the opening voltage of the dinistor VD7, it will breakdown and discharge the capacitance through the diode bridge VD1-VD4, as well as resistance R1 and control electrode VS1. To open the triac, an electrical circuit of diodes VD5, VD6 of capacitor C2 and resistance R5 is used.

It is required to select the value of the resistor R2 so that at both half-waves of the mains voltage, the triac of the regulator operates reliably, and it is also required to select the values ​​of the resistances R3 and R4 so that when the variable resistance knob R4 is rotated, the voltage at the load changes smoothly from minimum to maximum values. Instead of the triac TS 2-80, you can use TS2-50 or TS2-25, although there will be a slight loss in allowable power in the load.

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

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

Capacitor C1 from 0.1 ... 1.0 uF. Resistor R2 1.0 ... 0.1 MΩ. The triac is switched on by a positive current pulse to the control electrode at a positive voltage at the conditional anode output and a negative current pulse to the control electrode at a negative voltage of the conditional cathode. So the key element for the regulator is to be bidirectional. You can use a bidirectional dinistor as a key.

Diodes D5-D6 are used to protect the thyristor from possible reverse voltage breakdown. The transistor operates in the avalanche breakdown mode. Its breakdown voltage is about 18-25 volts. If you do not 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 H2000. The thyristor can be replaced with KU201

The circuit of this power regulator is similar to the circuits described above, only an 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 blocking of the triac and disconnection of the load.

C1, C2 - 0.1 uF, 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 adjust the load power in circuits up to 2000 W, incandescent lamps, heaters, a soldering iron, asynchronous motors, a car charger, and if you replace the triac with a more powerful one, you can use it 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 mains voltage after a selected number of missed half-cycles.

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

Pin 3 will be set to logic 1. The thyristor will be open. All power will be allocated to 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 unit level will be periodically at all outputs. However, if the switch is set to output 5 (vyv.1), then the count will only occur up to 5. When the pulse passes output 5, the microcircuit will be reset. The count will start from zero, and a logical one level will appear at pin 3 for the duration of one half-cycle. At this time, the transistor and thyristor open, one half-cycle passes into the load. In order to make it clearer, I give vector diagrams of the operation of the circuit.

If you want 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, it will be possible to 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 in its internal composition. The maximum input voltage of the KR1182PM1 chip is about 270 volts, and the maximum load can reach 150 watts without using an external triac and up to 2000 watts using, and also taking into account that the triac will be installed on a radiator.

To reduce the level of external interference, capacitor C1 and inductor L1 are used, and capacitance C4 is required to smoothly turn on the load. Adjustment is carried out using the 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 the blinking visible to the eye. The circuit makes it possible to adjust the power within eight preset values.

There are a huge number of classic thyristor and triac controller circuits, but this controller is made on a modern element base and, moreover, was a phase one, i.e. it does not pass the entire half-wave of the mains voltage, but only some of it, thereby limiting the power, because the opening of the triac occurs only at the desired phase angle.

POWER REGULATION

Most often, power regulators of devices are made on trinistors, using it as a powerful output key. But the trinistor in the AC circuit is inconvenient in that it requires power through a rectifier bridge, which, with a high load power, must be installed on a radiator. In this regard, a triac is more convenient for a key element. The main difference is the possibility of switching not only direct, but also alternating current, which can flow in any direction - both from the anode to the cathode, and in the opposite direction.

For reference: triacs with a positive voltage at the anode can be switched on by pulses of any polarity applied to the control electrode relative to the cathode, and with a negative voltage at the anode - by pulses of only negative polarity. Controlling a triac with direct current requires a lot of power, and pulse control requires a shaper that provides short pulses when the mains voltage passes through zero, which reduces the level of interference compared to regulators that use the phase-pulse control method.

The power control device contains a triac, a time (phase) delay unit, a compensating circuit and a power source. Compensating circuit R8 C2 to the voltage of the zener diode VD3 adds a voltage value proportional to the supply voltage. This amount is the interbase voltage of the unijunction transistor KT117. Reducing the supply voltage reduces the supply voltage of the transistor and causes a decrease in the time delay. From the well-known circuit of a triac power regulator on the BT136-600 and the DB-3 dinistor, this one differs in the stabilization of control pulses and, accordingly, greater accuracy and invariability of the output voltage.

When setting up a power control device, it is necessary to connect it to the network with a load through, and install a voltmeter in parallel with the load. By changing the voltage with a variable resistor R8 at the input of the regulator, we achieve the minimum voltage at the load. The transformer is made on a Sh5x6 core, the primary winding is 40 turns, the secondary is 50 turns PEL-0.2 - 0.3. In my version of the power control device, I installed a transformer on a K20x10x6 ferrite ring with two identical windings of 40 turns each - everything worked fine. For visual control of the voltage (power) at the load, I installed a small AC voltmeter assembled from the recording level indicator of a reel-to-reel Soviet tape recorder. We connect it naturally in parallel with the load. red glow indicates that the power control device is connected to the network and the scale is illuminated.

An active load with a power of up to two kilowatts can be connected to this regulator - electric stoves, electric kettles, electric fireplaces, irons, etc., and when replacing the triac with a more powerful one, for example TS132-50, up to 10 kW. A real use case: a neighbor is constantly knocking out plugs with 16 A automatic machines when operating an electric kettle Tefal 2 kW. Replacing them is impossible, since he does not live in his apartment. The problem was solved by this adjustment device, set at 80% power.

Useful improvements: when working with an inductive load, an RC circuit must be connected in parallel with the triac of the power regulator to limit the rate of rise of the anode voltage. Any triac regulator is a source of radio interference, so it is desirable to equip the power regulator with a radio interference filter. The LC radio noise filter is a conventional G-filter with a coil and a capacitor. As a choke L, a coil of 100 turns of wire wound on a ferrite rod with a diameter of 8 mm and a length of 50 mm is used. A wire diameter of 1 mm corresponds to a maximum load power of approximately 700 W. The fuse for the rated load current protects the triac from a short circuit in the load. When setting up, observe safety measures, since all elements of the power control device are galvanically connected to a 220 V network.

Questions and comments on the scheme - on

SEVERAL PRINCIPAL DIAGRAM OF POWER CONTROLLERS

POWER REGULATOR ON TRIAC

The features of the proposed device are the use of a D-trigger to build a generator synchronized with the mains voltage, and a method for controlling the triac using a single pulse, the duration of which is automatically controlled. Unlike other methods of triac pulse control, this method is not critical to the presence of an inductive component in the load. The generator pulses follow with a period of approximately 1.3 s.
The DD 1 microcircuit is powered by a current flowing through a protective diode located inside the microcircuit between its terminals 3 and 14. It flows when the voltage at this terminal, connected to the network through a resistor R 4 and a diode VD 5, exceeds the stabilization voltage of the zener diode VD 4 .

K. GAVRILOV, Radio, 2011, No. 2, p. 41

TWO-CHANNEL POWER CONTROLLER FOR HEATING DEVICES

The regulator contains two independent channels and allows you to maintain the required temperature for various loads: the temperature of the soldering iron tip, electric iron, electric heater, electric stove, etc. The regulation depth is 5...95% of the power supply network. The regulator circuit is powered by a rectified voltage of 9 ... 11 V with transformer isolation from a 220 V network with a low current consumption.

V.G. Nikitenko, O.V. Nikitenko, Radioamator, 2011, No. 4, p. 35

TRIAC POWER CONTROLLER

A feature of this triac controller is that the number of mains voltage half-cycles applied to the load at any position of the control element turns out to be even. As a result, the constant component of the consumed current is not formed and, consequently, there is no magnetization of the magnetic circuits of the transformers and electric motors connected to the regulator. Power is regulated by changing the number of periods of alternating voltage applied to the load in a certain time interval. The regulator is designed to regulate the power of devices with significant inertia (heaters, etc.).
It is not suitable for adjusting the brightness of lighting, because the lamps will flash strongly.

V. KALASHNIK, N. CHEREMISINOVA, V. CHERNIKOV, Radiomir, 2011, No. 5, p. 17 - 18

INTERFERENCE-FREE VOLTAGE REGULATOR

Most voltage (power) regulators are made on thyristors according to a phase-pulse control circuit. As you know, such devices create a noticeable level of radio interference. The proposed controller is free from this shortcoming. A feature of the proposed regulator is the control of the amplitude of the alternating voltage, in which the shape of the output signal is not distorted, in contrast to the phase-pulse control.
The regulating element is a powerful transistor VT1 in the diagonal of the diode bridge VD1-VD4, connected in series with the load. The main disadvantage of the device is its low efficiency. When the transistor is closed, no current flows through the rectifier and the load. If a control voltage is applied to the base of the transistor, it opens, a current begins to flow through its collector-emitter section, the diode bridge and the load. The voltage at the output of the regulator (at the load) increases. When the transistor is open and in saturation mode, almost the entire mains (input) voltage is applied to the load. The control signal forms a low-power power supply, assembled on a transformer T1, a rectifier VD5 and a smoothing capacitor C1.
The variable resistor R1 regulates the base current of the transistor, and hence the amplitude of the output voltage. When the variable resistor slider is moved to the upper position according to the scheme, the output voltage decreases, and to the lower position it increases. Resistor R2 limits the maximum value of the control current. Diode VD6 protects the control unit in the event of a breakdown of the collector junction of the transistor. The voltage regulator is mounted on a 2.5 mm thick foil fiberglass board. Transistor VT1 should be installed on a heat sink with an area of ​​at least 200 cm2. If necessary, the VD1-VD4 diodes are replaced with more powerful ones, for example D245A, and are also placed on the heat sink.

If the device is assembled without errors, it starts working immediately and requires little to no adjustment. It is only necessary to choose the resistor R2.
With a regulating transistor KT840B, the load power should not exceed 60 W. It can be replaced by devices: KT812B, KT824A, KT824B, KT828A, KT828B with a permissible power dissipation of 50 W .; KT856A -75 W.; KT834A, KT834B - 100 W; KT847A-125 W. It is permissible to increase the load power if the control transistors of the same type are connected in parallel: connect the collectors and emitters to each other, and connect the bases through separate diodes and resistors to the variable resistor engine.
The device uses a small-sized transformer with a voltage on the secondary winding of 5 ... 8 V. The KTs405E rectifier unit can be replaced by any other or assembled from individual diodes with a permissible forward current not less than the required base current of the regulating transistor. The same requirements apply to the VD6 diode. Capacitor C1 - oxide, for example, K50-6, K50-16, etc., for a rated voltage of at least 15 V. Variable resistor R1 - any with a rated dissipation power of 2 watts. When installing and setting up the device, precautions should be taken: the regulator elements are under mains voltage. Note: To reduce the distortion of the sinusoidal output voltage, try to eliminate the capacitor C1. A. Chekarov

MOSFET voltage regulator - transistors (IRF540, IRF840)

Oleg Belousov, Electrician, 201 2 , No. 12 , p. 64 - 66

Since the physical principle of operation of a field-effect transistor with an insulated gate differs from the operation of a thyristor and a triac, it can be repeatedly turned on and off during a period of mains voltage. The switching frequency of powerful transistors in this circuit is 1 kHz. The advantage of this scheme is its simplicity and the ability to change the duty cycle of the pulses, while slightly changing the pulse repetition rate.

In the author's design, the following pulse durations were obtained: 0.08 ms, with a repetition period of 1 ms and 0.8 ms, with a repetition period of 0.9 ms, depending on the position of the resistor R2 slider.
You can turn off the voltage at the load by closing the switch S 1, while the gates of the MOSFET transistors are set to a voltage close to the voltage at pin 7 of the microcircuit. With the toggle switch open, the voltage at the load in the author's copy of the device could be changed by resistor R 2 within 18 ... 214 V (measured by a device of the TES 2712 type).
A schematic diagram of such a regulator is shown in the figure below. The regulator uses a domestic K561LN2 microcircuit, two elements of which are used to assemble an alternator with adjustable swagger, and four elements are used as current amplifiers.

To eliminate interference on the network 220, it is recommended to connect a choke wound on a ferrite ring with a diameter of 20 ... 30 mm in series with the load until it is filled with 1 mm wire.

Load current generator on bipolar transistors (KT817, 2SC3987)

Butov A. L., Radio designer, 201 2 , No. 7 , p. 11 - 12

To check the performance and configure power supplies, it is convenient to use a load simulator in the form of an adjustable current generator. Using such a device, you can not only quickly set up a power supply, voltage stabilizer, but also, for example, use it as a stable current generator for charging and discharging batteries, electrolysis devices, for electrochemical etching of printed circuit boards, as a power supply current stabilizer for electric lamps, for "soft" start-up of collector electric motors.
The device is a two-terminal device, does not require an additional power source and can be included in the power circuit break of various devices and actuators.
Current adjustment range from 0...0, 16 to 3 A, maximum power consumption (dissipation) 40 W, supply voltage range 3...30 VDC. The current consumption is regulated by a variable resistor R 6. The more to the left in the diagram the slider of the resistor R6, the more current the device consumes. With open contacts of switch SA 1, resistor R6 can set the current consumption from 0.16 to 0.8 A. With the contacts of this switch closed, the current is regulated in the range of 0.7 ... 3 A.

Drawing of the printed circuit board of the current generator

Car Battery Simulator (KT827)

V. MELNICHUK, Radiomir, 201 2 , No. 1 2 , p. 7 - 8

When reworking computer switching power supplies (UPS), recharging devices (chargers) for car batteries, finished products must be loaded with something during the setup process. Therefore, I decided to make an analogue of a powerful zener diode with an adjustable stabilization voltage, circuit a of which is shown in fig. one . Resistor R 6 can adjust the stabilization voltage from 6 to 16 V. In total, two such devices were made. In the first variant, KT 803 was used as transistors VT 1 and VT 2.
The internal resistance of such a zener diode turned out to be too high. So, at a current of 2 A, the stabilization voltage was 12 V, and at 8 A - 16 V. In the second variant, composite transistors KT827 were used. Here, at a current of 2 A, the stabilization voltage was 12 V, and at 10 A - 12.4 V.

However, when regulating more powerful consumers, such as electric boilers, triac power controllers become unsuitable - they will create too much interference on the network. To solve this problem, it is better to use regulators with a longer period of ON-OFF modes, which clearly eliminates the occurrence of interference. One of the variants of the scheme is shown.