Telephone-Operated Ac Power Switch


Posted on Jan 4, 2013

Tones (from the DTMF) on the telephone line are detected by Ul. When a valid tone is received, pin 14 (D


Telephone-Operated Ac Power Switch
Click here to download the full size of the above Circuit.

AV) of Ul produces a positive pulse that is used to drive NAND gates U2A and U2B and then to latch binary data from Ul into Quad-D flip-flop U3 (Ul could be decoded into 16 bits, if required). The Q outputs of U3 drive optoisolators that control triacs TR1, TR2, and TR3. PS1 is a 6-V 150-mA dc adapter that operates from 120 Vac.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

FAST CHARGER controlled by a 68HC11
Diode feedback comparator
Car Battery Tester For Cranking Amps Circuit
10w audio amplifier
progosc
9V DC Adapter With Battery Backup
Modification of a telescope motor controller for autoguiding
Driving a fluorescent tube
Speaker Microphone Circuit
The interface circuit of dot matrix LCD display



Top