Motorola suggests this circuit in an 80's documentation. The circuit uses an inverter to produce a higher voltage for 9 V battery charge from a single cell.
This immobilizer circuit for vehicles was found in a 80’s Hands On Electronics. The circuit...
This circuit can be used as a clok in digital applications. Power supply is 5-V and the pins for...
With this preamplifier it is possible to use a small speaker as a microphone. The circuit is also...