This circuit is based on the light comparison of two LDR sensors. We found it in a 90s Popular Electronics. The transistor must be according to the indicator or load being driven.
This circuit was found in documentation from the 80s. The circuit did not include resistors from...
This circuit used in instrumentation is suggested by National Semiconductor, now Texas Instruments and...
The source shown in the figure provides output voltages in the range of 1.2 to 25 V with currents up...