Telephone handset tone dial encoder


Posted on Jan 1, 2013

This encoder uses a single contact per key keyboard and provides all other switching function electronically. The diode between terminals 8 and 15 prevents the output going more than 1 volt negative with respect to the negative supply V-


Telephone handset tone dial encoder
Click here to download the full size of the above Circuit.

The circuit operates over the supply voltage range from 3 volts to 15 volts.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Heartbeat monitor
Electronic crowbar for AC or DC lines
Temperature-to-Frequency Converter: Enabling Simple Telemetry
2 x 22W-BTL Car Audio Amplifier DA1553CQ Schematic Diagram
Argon/Krypton Ion Lasers
stabilizer circuit
mic 702 mictronics schematic diagram
Discrete Voltage Inverter
Step-Down Converter Controller
Remote Control On/Off Switch
Wolfstone Pyrotechnics
ZN414 portable Receiver
OCL AC negative feedback amplifier analysis
Auxiliary power supply circuit using variable speed
External circuit configuration CPU clock circuit



Top