With this circuit it is possible to receive and send audio signals simultaneously over the same telephone line. The circuit was found in an Elektor from the 90s. The power supply is symmetrical.
This circuit obtains phase-inverted signals from a single signal. The circuit uses two LM741...
This circuit was found in a 1963 magazine. The magazine no longer exists, but the circuit can be...
a This circuit was obtained from a 1978 Practical Wireless. It causes a low-power 1.5V lamp to...