Found in old documentation, this source uses an integrated circuit from that time, which is uncommon nowadays. The power source has a ripple below 1 mV.
This circuit is from the 1960 Mullard transistor manual. The transistors are germanium from the...
This circuit, which may have other applications, trips a load if the voltage on the telephone line...
This circuit was found in a 1986 documentation and can use any operational amplifier like the 741...