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

12-Bit dac with variable step size
Add-on-telephone-hold-button
High-accuracy ultrasonic range measurement system because of ߀?s C OS and ARM processor
laser asc
Audio AmplifierCircuit - 30 Watts
External audio spectrum display circuit diagram
Field scanning circuit circuit and sawtooth waveforms



Top