This circuit is from an old American documentation and its use in motorcycles with 12 V is suggested to power 6V radios. The transistor can be the BD136 and BC548.
Using the ULN-3784B this circuit typically supplies 5 W at 24 W. However, it can operate from 9 V....
S-meter is a signal strength meter used in radio transmission. Also known as Strength meter, in this...
This dual circuit was found in an 80s Siliconix documentation. The power source must be...