Diode, Transistor identification.. - Electronic Circuits Projects Diagrams Free

sonaiko · 9th December 2004, 06:54 PM

hello guys..
i have a diode and a transistor in my hands..
how would i know that this is the Anode side and that is the kathode side of the diode? the current flows from A to K right?

how would i know which is the base and which is the emitter and the collector in the transistor?

TheOne · 9th December 2004, 07:48 PM

Current will start to flow when the anode is more +ve than the cathode by about 0.7v for a silicon diode.

Transistors junctions will test like 2 diodes using a ohm-meter on the diode test function. The common terminal will be the base, and from here you should get 2 diode readings, one to the emitter, and one to the collector. The one with the lowest reading (look carefully on the digital readout) will be the base-collector junction. You should get high resistance between collector-emitter. For NPN the "anode" side of the virtual diodes will be on the base and for PNP it will be the cathode.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

9th December 2004, 06:54 PM	(permalink)
sonaiko	Diode, Transistor identification.. hello guys.. i have a diode and a transistor in my hands.. how would i know that this is the Anode side and that is the kathode side of the diode? the current flows from A to K right? how would i know which is the base and which is the emitter and the collector in the transistor? __________________ subzero... wins..

9th December 2004, 07:48 PM	(permalink)
TheOne	Current will start to flow when the anode is more +ve than the cathode by about 0.7v for a silicon diode. Transistors junctions will test like 2 diodes using a ohm-meter on the diode test function. The common terminal will be the base, and from here you should get 2 diode readings, one to the emitter, and one to the collector. The one with the lowest reading (look carefully on the digital readout) will be the base-collector junction. You should get high resistance between collector-emitter. For NPN the "anode" side of the virtual diodes will be on the base and for PNP it will be the cathode.