The principle and production of controlling multiple groups of lights with a single switch

Using a single switch to control multiple groups of lights not only saves a lot of switches, but also adds fun to your DIY crafts.

As shown in the attached diagram, when the power switch K is turned on for the first time, the 1# lamp lights up immediately. Since the voltage on the capacitor C3 cannot change suddenly, the optocoupler G is only turned on at the moment the switch K is turned on (about 0.5 seconds), but soon G is turned off. In addition, at the moment K is turned on, the voltage on the capacitor C4 cannot change suddenly, so the thyristor S1 will not turn on (the voltage has not been established when the switch K is just turned on C1, and similarly S2 will not turn on). Therefore, the 2# and 3# lamps will not light up.

If you want to light up the 2# lamp, you only need to turn off the power switch K a few seconds after the 1# lamp is lit, and then turn it on immediately. Then both the 1# lamp and the 2# lamp will light up. The reason is that after the switch K is turned on for the first time, a stable DC voltage has been established on the capacitor C1, and this voltage is applied to the anodes of the thyristors S1 and S2. At this time, the photocoupler is turned on for a short time due to the coupling of C3 when the switch is turned on for the second time, and the thyristor S1 can be triggered to turn on. At this time, the relay J1 works, and its contact J1-1 is connected, and the 2# lamp lights up.
At the moment when the switch K is turned on for the second time, the thyristor S2 will not turn on, because there is an R5 and C5 integration circuit on the cathode of S1. At the moment when S1 is turned on, C5 cannot establish a gate voltage sufficient to trigger S2. When C5 establishes the trigger voltage required by S2, the photocoupler has been turned off.

If you want to light up the 3# lamp, you only need to open the switch again and then close it again, the thyristor S2 will be turned on, and the 3# lamp will light up. The working process is similar to the above. It can be seen that according to the above working mode, the circuit can increase the number of 4#, 5#, etc. lamps by adding the same circuit levels as S1 and S2. When operating, you only need to keep turning on and off the power switch to light up each lamp in turn. That is, a single switch can control multiple lamps.