Using an operational amplifier, this circuit from a 90s Popular Electronics, is characterized by its high sensitivity. R5 can be added to control the gain.
This circuit provides a signal of higher frequency the greater the intensity of the light incident on...
This circuit was obtained from a 1978 Practical Wireless. It generates a low frequency, low...
This circuit can be used as a lockable shield. A pulse activates the relay that remains on even...