This circuit for testing old analog lines was published in April 1986 Radio Electronics magazine. The circuit uses only passive components.
September 2017 - The new LDOs of STMIcroelectrinics LDLN025 for currents up to 250 mA and 1.5 to...
We found this circuit, which should only be used with incandescent lamps. In the Motorola Linear...
This version operates in the opposite way to the previous one, triggering when light falls on the...