This circuit was obtained in an 80s documentation on telephony. The components used are TTL, and the power must be made with 5 V.
This circuit was found in a 1967 Ferranti manual and can be applied to modern operating...
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...
We found this circuit in a publication from the 1970s. It produces intermittent clicks on a...