Micro metronome (CB20743E)

This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light sources.

12 W Amplifier (CB13679E)
The integrated circuit of this amplifier is not very common today. The output transistors can be...
Coded Switch using Reed Switches (CB3974E)
This circuit is from a1970 documentation. R1 may have 10k and P1 47k. The transistors can be BC558...
TTL Logic Probe (CB1461E )
This circuit is from a 1977 documentation. It is powered by the power supply of the circuit under...