Universal timing controller circuit

The universal timer in Figure 1-1 can be set for 5 minutes to 18 hours at a time; the cycle time is from 5 minutes to 20 hours; the total time of timed on and timed off is 18 hours. The control power is below 500W, and the power consumption of this circuit is less than 1W.

The time base circuit NE555 and C3, W, R1, and R2 form a time base pulse generating circuit. Adjusting W can change the pulse period from 5 minutes to 2 hours. R2 plays the role of extending the pulse period. Without R2, the longest pulse period is 1 hour. The counter CD4017 and D2-D10, K1-K10, etc. form a delay multiplication circuit. This circuit extends the pulse period by 10 times in total. K1-K10 controls the multiplication multiple, which is a product relationship with the output pulse period of NE555. BG and bidirectional thyristor form an AC power supply control circuit. When the BG base is high, it is turned on, the SCR is triggered to turn on, and the controlled circuit works. When the BG base is low, it is turned off, the SCR is turned off, and the controlled circuit stops working. C1, DW, D11, and C2 form a simple DC supply circuit to provide 12V DC power for the timing circuit.

In one-time timing, K12 is set to "1" and K1 is open. After NE555 outputs 10 pulses, EN of CD4017 is high level and stops counting. At this time, press AN, CD4017 counts again, and the maximum time for one-time timing is 18 hours.

When the cycle is timed, K12 is set to "2" and CD4017 counts the cycle. The maximum time for each cycle is 20 hours.

The timed opening and closing are controlled by K1-K10.