This circuit was found in a 90s Popular Electronics. The circuit uses 4 bicolor LEDs to indicate signals of both TTL and CMOS logic. The circuit is powered by the source of the circuit under test.
This Radio Electronics circuit, in an 80's edition, decodes the 67 kHz signal used at the time to...
This circuit was found in a 1966 General Electric documentation. The circuit makes use of PUTs...
This circuit was found in an old Electronic Design. It makes use of sidacs and operational not very...