This TTL circuit was found in a 1978 technical documentation. The power must be supplied with 5 V. It converts ASCII characters to hexadecimal.
I found this circuit in an English publication from 1989. This configuration can be mounted with...
This circuit can be used to amplify signals up to 150MHz. The JFET can be MPF102 or BF245 and the...
In this circuit of 1987 the player has to briefly press one of the keys trying to hit which LED...