Found in the May 1971 Radio Electronics magazine, this is the circuit for a commercial high-impedance instrument. The circuit uses 4 transistors and is powered by 2 9 V batteries.
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...