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.
We found this circuit in an American documentation from the 60's. The transistors are made of...
The accuracy of this circuit depends on adjustments made with capacitors of small tolerances of known...
The figure shows how to implement an OR function with two inputs, using a relay. The relay...