Flasher CA3130 (CB22004E)

Found in an English documentation from 1977, this flasher or pulser circuit drives an LED. The frequency depends on C2.

PC address decoder (CB20536E)
This TTL decoder circuit for PC ports was found in a document from 1992. The power supply can be...
Reversible sequential for LED (CB6945E)
This circuit is from an old Popular Electronics, but it can be easily implemented nowadays, even...
Peak indicator with hysteresis (CB21973E)
The basis of this circuit is a CA3130 operational amplifier. The transistor can be BC548, and the...