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 source for common, non-high-power car radios can be used on the bench. It was found in a...
This circuit was found in Maxim's documentation from the 80's. The integrated circuit is from that...
) We found this circuit in a 1988 documentation, but it uses components that are still common...