25-09-2012, 11:59 AM
Mosquito repeller power saver
Mosquito repeller power saver.pdf (Size: 25.16 KB / Downloads: 35)
Description:
Almost all liquidator type mosquito repellers are rated 5Watts. It is a pretty energy
consuming game when these repellers are operated
throughout the night. Even though these liquidators are switched ON and OFF in discrete intervals
there will be no considerable loss in the effectiveness and more over there will be a great saving of
energy.
Power supply:
230V AC supply is given to the center tapped transformer and then given to the diode D2 and
D3 which is acting as a half wave rectifier. The rectified output is now given to the capacitor C1
which will filter out the ripples.
Timer:
Timer which is nothing but a astable multivibrator. Resistor R2 is connected between VCC and
the discharge pin (pin 7) and another resistor (R1) is connected between the discharge pin (pin 7),
and the trigger (pin 2) and threshold (pin 6) pins that share a common node. Hence the capacitor (C
2) is charged through R1 and R2, and discharged only through R1, since pin 7 has low impedance
to ground during output low intervals of the cycle, therefore discharging the capacitor.
Relay:
When the power is switched on the output of the IC goes high. This makes Q1 to conducts and
the relay connects the mains supply to the repeller plugged in the socket shown. After the set time
the output of the IC goes low and now the repeller is removed from mains by the relay. This cycle
repeats and the repellent will be switched ON and OFF in frequent intervals, saving a lot of power.