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.
Published in an old Popular Electronics, this circuit makes use of components that are still...
This high-power flasher for incandescent signaling lamps was found in a 1980s General Electric...
This circuit takes advantage of the LC constant of a capacitor and the coil of a relay to...