This ultra-low noise amplifier and simple power supply was found in Analog Devices documentation from the 90's. The circuit can be implemented with modern equivalent components.
This circuit was found in a Electronics World of 1968. The integrated circuit is the MC1320P from...
The circuit presented is from the Linear Applications Handbook of the National Semiconductor of...
Using an LDR as a sensor and an operational amplifier this circuit was found in the Encyclopedia of...