This circuit was found in 1967 Philips documentation. It uses transistors from that time. Transistors can be replaced with modern equivalents.
An OR gate can be implemented with an LM3900 transconductance operational amplifier. The circuit is...
This circuit was obtained in an old American documentation, remembering that the 566 is the double...
This circuit has a consumption of only 3.7 mA and can be installed in vehicles or objects for...