We found this circuit in an American documentation from the 1990s. The circuit is based on the LM3909, a low power oscillator from National Semiconductor.
This circuit uses a LM3900 Norton amplifier and a 2.7 V zener diode to supply a current of 1 mA to...
This simple circuit turns on a small lamp (or LED) when the light stops shining on the sensor for...
The LM123 series (223 and 333) is manufactured by several semiconductor companies. The circuit below...