Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then disconnect the charger. The transistor may be a general purpose type.
This circuit works on analog I/O ports and was suggested by an Electronic Design from the 90s. It...
This circuit uses two sensors that are placed at the intersection of a miniature railroad, causing the LED...
Found in Radio Electronics from the 90s, this circuit uses a thermistor as a sensor that can have...