Since the 2N3904 is an NPN transistor, that means the base needs positive biasing (appropriate voltage levels and resistance) to turn on the collector emitter junction for proper current flow. Use of a load resistor (R1 above) is also important so there is not too much current being driven through the LED and transistor. a d v a n c e d s e m i c o n d u c t o r, i n c. rev.b 7525 ethel avenue • north hollywood, ca 91605 • (818) 982-1202 • fax (818) 765-3004 1/1
This is the Transistor Prototype PCB Design Kit with 2N3904 & 2N3906 Transistors.This kit is what you need to develop numerous different transistor circuits. It includes the extremely useful NightFire Prototype Transistor PCB along with some of the very popular 2N3904 NPN & 2N3906 PNP Transistors in the standard leaded TO-92 package. 2N2905 2N2907 GENERAL PURPOSE AMPLIFIERS AND SWITCHES DESCRIPTION The 2N2905 and 2N2907 are silicon planar epitaxial PNP transistors in Jedec TO-39 (for 2N2905) and in Jedec TO-18 (for 2N2907) metal case. Theyare designed for high speedsaturated switchingand generalpurposeapplication. INTERNAL SCHEMATIC DIAGRAM November 1997 ABSOLUTE MAXIMUM ... SparkFun is an online retail store that sells the bits and pieces to make your electronics projects possible.
– Information on datasheets The Transistor (NPN) • A current amplifier … – Makes small currents BIGGER • The 2N3904 Transistor β = 30-400 C= Collector B = Base E = Emitter Important 2N3904 Specifications from the datasheet Note high maximum ratings BUT 200mA maximum current 2N3904 Datasheet • Posted on the ME456 website