The circuit presented was suggested by Texas Instruments in an opto-electronics manual. The transistor can be the BC548 and the supply voltage depends on the application.
The current of this charger is determined by Rs. The circuit is from the 1982 SGS linear...
This circuit is used to connect an additional capacitor to a tuned circuit of a VFO. The circuit...
This alarm does not interrupt its operation when the power is cut. A battery is kept at a constant...