This circuit was obtained from the July 1970 issue of Radio Electronics magazine. Zeners are power types that can provide a good current to the circuit. Selection is made by rotary switch.
This circuit, which may have appeared elsewhere on this site, is from the integrated...
We found this circuit in a 90s Radio Electronics. The circuit uses a transconductance operational...
This circuit was obtained from an 80's documentation from General Electric. The circuit uses an...