It works perfectly, however, it is very quiet when listening. This makes no real difference over 10 meters or 100.
Is there a simple way I can increase the volume perhaps by increase voltage or changing the resistor? I know our local telephone network actually runs on 12v - I am just nervous to try and break the phones.
You found an extremely simple circuit. Most extremely simple circuits work poorly.
In Canada, the phone network runs off 48V to 50V, not 12V. A phone draws enough current to drop it to about 8V. If the circuit does not limit the current then the phones might burn up. A phone line does not use resistors that reduce the levels, instead it uses transformers that pass audio without loss and pass DC to the phones.
Telephone speaker vol increase
Posted - Apr 15 2010 : 10:20:06 AM
