This circuit was found in the December 1992 issue of Radio Electronics magazine. The current is a few mA and the maximum input voltage is around 12 V.
This circuit can measure frequencies up to just over 1 MHz and uses CMOS technology. The circuit is...
This variable oscillator was found in a Mullard transistors manual from 1960. The resistor R5 is...
This circuit, from a 1988 documentation, consists of an automatic temperature control using an NTC...