We found this sophisticated meter circuit in an article in Radio Electronics magazine from June 1959. The article taught how to assemble it. Transistors are common types at the time.
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...
June 2016 - It can be purchased from Mouser Electronics the TAS5720x the evaluation module from...
This circuit was found in a National Semiconductor manual from the 1970s, appearing in articles and on...