The presented circuit uses a PNP transistor, which can be the BC558. Observe the polarity of the supply. The circuit is suggested by Texas Instruments opto-electronic documentation.
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...