Offer simple triac controller, which operate more than year. It can be used, for example, to control a flow heater, powerful brushed electric motor, welding machine, electric furnace. Scheme the regulator shown in Fig. 1. As the power key is used VS1 triac TS-50-6, capable of switching load capacity of up to 8 kW.
The management node contains a triac the pulse generator on a unijunction transistor VT1. With the help of variable resistor R3 regulate the pulse delay since the transition of the mains voltage through zero, than change the angle the inclusion of the triac and given to the load capacity. Transistor VT2 is power amplifier pulse that opens the triac. Transformer T1 is made on the annular magnetic core size K20x12x6 ferrite 2000NM. It the primary winding (I) contains 60 turns of wire PELSHO 0,1, secondary (II) - 40 turns of wire PELSHO 0.2. Winding must be reliably insulated from each other. Insulation shall be rated for a voltage of less than 300 V. the Node control is fed from the mains via the quenching resistors R1. R2 and diode bridge VD1. The rectified bridge voltage stabilized by the Zener diodes VD2 and VD3.
The triac should be placed on the heat sink area of not less than 300 cm2, other the elements of the device do not require cooling.
Instead of the triac TS-50-6 you can set two SCR T-50-11. combining their anti-parallel, as shown in Fig. 2. The transformer T1 in this case should have two identical secondary windings.
Since triac (trinistorny) controller generates radio interference, it recommended well screened and included in the network through the filter (see diagram on Fig. 3).
The magnetic circuit of the inductor L1 ø 12x15 ferrite 2000NM. Coils contain 15...20 turns of wire, whose cross section is selected on the basis of power load, and the insulation must withstand the full voltage. For best noise suppression both windings simultaneously harassed folded in half wire. Capacitors C1-C3 - MBGP or other type calculated voltage at least 400 V.
Author: V. Sorokov, Sergiev Posad, Moscow region.