TTL Counter (CB21360E)

This counter from 0 to 9999 was found in English documentation. The power source must be 5V with at least 1A.

24 V supply with 12 V regulator (CB12089E)
With this circuit it is possible to obtain a voltage of 24 V using a 12 V regulator. The maximum...
Precision tachometer (CB9347E)
We found this circuit in a 1965 publication by General Electric. The zener is 8.2 V x 1 W and the...
Telephone in use warning button (CB9465E)
This circuit was found in a Hands On Electronics from the 90s. It turns on an LED to indicate that...