This counter was found in the November 19983 issue of Radio Electronics magazine. The power supply can be between 3 and 12 V typically. The counting speed depends on C1.
This amplifier was found in an English publication from the 60's. The transistors are germanium of the...
We found this configuration in a 1974 technical documentation. It can test both TTL logic circuits and...
This circuit for 12 V x 2.2 W lamps was found in a documentation from the 70's. The circuit uses...