We found this circuit in a 1996 publication. Equivalent components can be tried, especially in the case of the photodiode. The circuit is powered by a 12 V source.
We found this multiple thermostat circuit in July 1980 Radio Electronics magazine. It uses...
Other operational amplifiers can be used on this unit gain amplifier. The circuit is from the 1993...
This interesting circuit with an indicator tube powered by a transistor inverter was found in...