The problem is that the microprocessor is only capable of supplying a small amount of current (amps). Why use a Transistor?įor microprocessors to control a load (in other posts), a program runs in the microprocessor, and based on conditions in the program, the microprocessor will decide to turn on or off a load. Remember, the Emitter is connected to + in a PNP transistor, and to – in an NPN transistor. A resistor limits the amount of current flow through the base, and current will flow from the emitter to the collector (the other two leads in a PNP transistor), then through the load to ground. The PNP transistor interrupts the positive side of a load (+), and when the base sinks to ground (again through a resistor), the transistor will conduct to energize the load. With a PNP transistor, the opposite occurs. With an NPN transistor, the load is interrupted on the negative (-) side of the load, and when a voltage (such as 5v) is placed on the base (the center conductor) through a resistor, the transistor will conduct and turn the load on. There are two main types of transistors: NPN and PNP.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |