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.

High Voltage Regulator (CB16679E)
This circuit is based on an integrated TIPL62 from Texas Instruments, uncommon today and an...
3 Tone Oscillator (CB4187E)
This circuit appears in other articles and suggestions for circuits in this section from other...
Precision PWM Generator (CB21335E)
This circuit was obtained from an Electronic Design from the 90's. The circuit generates signals at a...