Following the American FCC rules, this 90s Radio Electronics circuit shows how to use a transformer to isolate the telephone line from an amplifier circuit.
This transmitter was sent by contributing reader Adriano Muniz Moura from Pirapora – MG. It is in...
This circuit indicates whether the voltage to be measured is higher or lower than the zener diode...
An interesting application that can be implemented with the LM139 is the pulse width modulator. This is...