This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The power supply does not have to be symmetrical.
Found in a 90s Popular Electronics, this circuit is interspersed between the filter and the...
This circuit is from an 80's documentation. The integrated circuit is from the time and the...
This circuit was found in a 80s American documentation. The zener diodes determine the points of...