This circuit uses an HA2400 consisting of 4 digitally controlled operational amplifiers. The circuit is from a Radio Electronics magazine from March 1980. The power supply must be symmetrical.
We found this ionizer circuit in a Radio Electronics magazine from May 1971. The high voltage...
This well-designed bistable configuration is for educational purposes. We found it in the...
This high input impedance circuit makes use of two operational ones that are still common. The...