Written by: Newton C. Braga

In figure 1 we have the complete circuit of the time light. The maximum interval is of the order of a few minutes and depends on C1.

 


 

 

 

Utilities:

• Lighting of hallway lights and elevator halls

• Timed activation of various loads such as fans and heating elements.

• Timing of industrial automations where high accuracy is not required.

 

Constructive Details:

The printed circuit board for mounting the time light is shown in figure 2.

 

Figure 2
Figure 2

 

 

The capacitor C1 is a high voltage electrolytic, for 200 V if the grid is 110 V and 400 V if the grid is 220 V. The SCR must be mounted on a heat radiator. The values in parentheses are for the 220 V network.

The load must be resistive and the control is half wave.

 

Semiconductors:

SCR - TIC106B or D - SCR for 110 V or 220 V according to the local network

D1 - 1N4004 (110 V) or 1N4007 (220 V) - silicon diode

 

Resistors: (1/8 W, 5%)

R1 - 100k ohm

R2 - 47 k ohm

 

Capacitor:

C1 - 2 uF at 16 uF x 200 or 400 V - high voltage electrolytic - see text

 

Several:

X1 - incandescent lamp up to 100 W

Printed circuit board, heat radiator for SCR, wires, solder, etc.