The timer with 555 timers integral is supplied without a transformer from the mains voltage of the circuit. However, it is necessary to pay close attention to working with such connections, since there will be high danger. Materials R1, C1, C2, D1, D2 and D3 are materials that form the actual feed circuit. The working voltage of the C1 and C2 condenser units should be 25v D3 12V zener and R1 resistor power will be 1W 1U condenser should reduce the mains voltage by 220V.
It is the D3 zeneri that determines how many volts the output of the Beseleme circuit will be. The U1 555 integrator is the integrated timer that is built by different companies such as NE555, LM555 and so on. varieties are all the same. In the circuit, the duration of the timer can be determined by changing the resistance of R4, or instead of this resistance, the trimpot may be used.
OPERATION OF THE CIRCUIT;
When the circuit is first energized, the capacitor C4 will start to charge through the resistor R4. The R4 resistor determines the charging time of the capacitor C4 and during this time the contact of the RL1 is in the open position because the output Q of the U1 connector is in position 1. The C4 capacitor will be fully charged after a period of time and when it reaches 12V, output Q of the U1 connector will be pulled to 0V. Thus, relay RL1 will close the contact and D4 LED will take the ten position.