Found in the February 1983 Radio Electronics magazine, this circuit uses a FET and has good gain at the frequencies determined by the components. The FET is any general-purpose FET.
The charging current of this circuit is controlled by the temperature of the accumulators, which is...
This circuit was found in a 1987 magazine. It measures the resistance of the skin using a...
This circuit shuts off and locks the power to a load in the event of a failure. The circuit is from...