This circuit emits a warning sound when night falls. The circuit is from a Hands On Electronics from the 90s. The Sensor is a common LDR and R6 adjusts the trigger point.
The operational amplifier used in this circuit is not common today, but it can be implemented with...
This circuit is used to test triacs. It can be connected in series with a resistive load such as...
In the figure we have the configuration of a transistor as a temperature sensor. The circuit is...