Delayed light circuit using relay (5)

The delayed light circuit using relays is shown in Figure 7]. S131 and SB2 are both light-on buttons.
They can operate the light F even if they are installed in different places. The light-emitting diodes LED l and LFr)2 should be installed at SB1 and SB2
. The indicating switch position is convenient for use.
    When you need to turn on the light, just
press any one of SB1 and SB7
, and the lamp E will light up.
LEDI , LED2 goes out. At
the same time, the alternating current at both ends of the lamp 1
passes through a
simple capacitor
step-down rectification and voltage stabilizing circuit composed of (j, c, VS, VD1, etc., and
the output at both ends is about 12V Stable
DC voltage. Since
the resistance value of the ruler is much smaller than the RP ten Torr, VT1 is cut off and VT2 is turned on, so the relay K suctions
the stage and the moving stage gets an electric shock. Kl closes the stage, making the circuit self-locking. At the same time, the moving breaking contact k2 jumps On, since the voltage at both ends of the capacitor G cannot change suddenly,
VTI still remains in the cut-off state, so the lamp F can continue to emit light. Then, the 12V DC current flows through RP and R to '
, so that (1. The voltage at both ends is constantly high, When it rises to 3×0 65V, VD2, VD3 and VT1 are all turned
on, the VT2 cut-off relay K loses power and is released, its contacts kl and k2 are reset, the light F is turned off, and
LED1 and LED 2 light up to indicate the switch position. The trimming resistor RP can be used to change the delay
time when the light turns on. K is made of small electromagnetic relays such as JRX-13F and DClZV . It has two sets of switching contacts and can meet the requirements
of the circuit .