This is the receiver from the previous alarm system. The circuit is from Radio Electronics, April 1989, and has an LDR as the sensor. Optical devices should be used to improve performance.
Found in a1969’s neon lamp documentation, this circuit uses a high voltage transistor. The output...
This circuit is intended to match impedances for observing signals on an oscilloscope. The FET...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...