To control the switching on and off loads of different places a device shown in the figure.
When you click on one of the buttons SB1 SBn...through the resistor R1 to the control electrode thyristor VS1 receives a positive pulse. The thyristor VS1 opens and includes a magnetic switch KM1, who their contacts KM1.1...KM1.3 includes load, and the contacts 1.4 km prepares the circuit of the thyristor VS1. If you press any of the buttons SB1 SBn...voltage with the charged capacitor C2 is supplied to the thyristor VS1 in reverse polarity, which is closed and turns off the magnetic contactor. Touching one of the buttons SB1 SBn...the starter again and turn on the load.
This device can be used for motor control and for lighting control.
Resistor R2 type sew-7,5 200 Ohms, you can use two resistors MLT-2 430 Ohm, connected in parallel.
The C1 capacitor 20 UF 450 V, C2 -0,1 UF 400V.
Author: V. Yakovlev, UT5WK, Shostka