The figure shows how to drive a load up to 300 mA with an LM3900. The transistor can be a BD136. We found this setting in the 1994 National Semiconductor Linear Applications Handbook.
This dual adjustable power supply was found in the June 1990 issue of Radio Electronics magazine....
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
This circuit, from a 1973 documentation, can be made with BC549 transistors. The frequency depends on...