This circuit was found in an American documentation from the 70s. The operational amplifier is from that time. Modern equivalents can be used.
This circuit was found in Linear Circuits Applications of Texas Instruments, originally using the...
This circuit, from a 1988 publication, consists of a timer that activates a relay at the end of a...
This configuration was found in the Texas Instruments optoelectronics manual. PNP transistors...