The 38 kHz infrared rays generated by the remote control are received by IR receiver. Pin 2 of IR is connected to ground, pin 3 is connected to the power supply through R1 and the output is taken from pin 1. The output pulse is set to pin 2 of 555 timers.
Then in pin 2 if the voltage is less than one third of Vcc, a trigger pulse is active.The pulse signal is fed to clock pin 4 of counter IC 74109. Pin 8 of 74109 IC is grounded, pin 16 is connected to Vcc and pin 3 is grounded. The output of 74109 IC is taken from its pin 7. Q1 connected to pin 7 through R3 of IC 74109 drives the relay RL.
The relay is connected through a fan and a regulator. It gets connected to live terminal of AC mains via normally opened (N/O) contact when the relay energizes. If we want to operate a DC 12 volt relay then we have to use a regulated DC 12 volt power supply for DC 12 volt Relay and we have to remember that the circuit voltage not be exceeded more than DC 5 volts.
Fig: Layout
of Remote control regulated Ceiling Fan
JK flipflop/IC 74109:
The 74109 are dual positive-edge triggered, JK flip-flops with individual J, K inputs, clock (CP) inputs, set (SD) and reset (RD) inputs; also complementary Q and Q outputs.The set and reset are asynchronous active LOW inputs and operate independently of the clock input. The J and K inputs control the state changes of the flip-flops as described in the mode select function table. The JK design allows operation as a T-type flip-flop by tying the J and K inputs together. In the T Flip-flop sequentially if the i/p is 1, the o/p is 1, then o/p is 0 and again 1.