Simple circuit times bathroom fan


Posted on Apr 15, 2012

Forget to turn off the ceiling fan in your bathroom? Install the simple timer in Figure 1. It`s located out-of-sight in the fan unit, and you turn it on via the wall switch. The circuit costs virtually nothing, using `junk` parts. When ac power appears, a simple rectifier develops approximately 7V across filter capacitor C. This voltage powers the LM2905 analog timer and simultaneously triggers it via trigger-input Pin 1; output Pin 7 then goes low, turning on the solid-state relay and fan.






Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Graphical Waveform Synthesiser
amplitude modulator
Audio booster
PC Fan Speed Controller - For a Low-Noise PC
connecting voltmeter and ammeter
door loock circuit
Water Sensor Alarm Circuit
Low-Power Car/Bike USB Charger
PIC Projects
Tuned-base Armstrong oscillator
Open Source USB Generic HID devices based on the PIC18F and Windows



Top