Low battery indicator 555 (CB9551E)

This circuit can operate with different voltages, depending on the zener used. We found it in a 90s American documentation.

Current Amplifier (CB6136E)
This circuit was found in a British documentation from 1969. It can be implemented with modern...
Voltage Controlled Oscillator (VCO) (CIR103E)
A simple VCO using two inverters in a ring configuration is shown here. A VCO is a circuit in...
Complementary Tourch Switch (CB3852E)
The four gates of a 40111 IC are used in thes two-out circuit. The output chages their state in a...