This TTL circuit was found in a 1978 technical documentation. The power must be supplied with 5 V. It converts ASCII characters to hexadecimal.
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...
Using only one general purpose transistor this circuit is powered by batteries. The lamp of the...
Can be used as a shield, this old American documentation circuit offers digitally selected...