Based on the TCA6600 or TCA5500 this circuit was found in a 90’s European documentation. The integrated circuit used is not very common today.
We find this circuit in a 1974 Motorola PUTs (Unijunction Programmable Transistors) documentation. The circuit...
This circuit releases a lock only if the correct 4-digit sequence is entered. The circuit uses...
This alternating flasher was found in a 1980s documentation. The transistors may be equivalent such...