This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
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...