Position: Index >

Dark-Activated Alarm With Pulsed Tone Output Circuit

2016-02-21 01:24  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.


NOR gates a and b form a low-frequency oscillator that is activated when the CDS cell, under dark conditions, causes NOR gate a to see a logic zero at one input. This low-frequency (10 Hz) gates a high-frequency oscillator (c and d) to oscillate at around 1000 Hz. Rl can be varied to change the pulse rate and R2 to change the tone.
Dark-Activated Alarm With Pulsed Tone Output Circuit

R3 sets the trigger point.



Reprinted Url Of This Article:
http://www.next.gr/sens-detectors/light/dark-activated-alarm-with-pulsed-tone-output-circuit-l14534.html