Purpose Transistors
A42 TO-92 General Purpose NPN Bipolar Transistors 100 Pcs 
20 Pcs 2N5551 General Purpose DIP NPN Bipolar Transistors 
Through Hole Bipolar General Purpose Transistors S8050D 100 Pcs 
S8050D NPN TO-92 General Purpose Transistors 100 Pcs 
50 Pcs NPN General Purpose Bipolar Silicon Transistors 
A42 TO-92 General Purpose NPN Bipolar Transistors 50 Pcs 
2N5551 DIP General Purpose NPN Bipolar Transistors 50 Pcs 
TO-92 General Purpose DIP NPN Transistors 2N3904 100 Pcs 
100 Pcs A92 General Purpose DIP PNP Bipolar Transistors 
Through Hole Bipolar General Purpose Transistors S8050D 100 Pcs 
100 Pcs Transistor S9012 STS9012, General Purpose PNP 
2N5551 DIP General Purpose NPN Bipolar Transistors 50 Pcs 
TO-92 General Purpose DIP NPN Transistors 2N3904 100 Pcs 
10 x 2N5087 PNP General Purpose Transistor 
2N5551 DIP General Purpose NPN Transistors 100 Pcs 
50 x S9012 40V 500mA 0.625W General Purpose Transistors 
SILICON TRANSISTOR-EG&G-PNP-GENERAL PURPOSE 
30x 2N3906 PNP General Purpose Transistor 3906 40V 0.2A TO-92 
50x 2N3906 PNP General Purpose Transistor 3906 40V 0.2A TO-92 
3 x BC109 BC109B NPN General Purpose Transistor – USA SELLER – Free Shipping 
(10) 2N6288 40-Watt Power TRANSISTOR 
50 Pcs A92 General Purpose DIP PNP Bipolar Transistors 
2N3906 National Semiconductor PNP General Purpose Transistors, Quantity 2000 
2N3904 National Semiconductor NPN General Purpose Transistors, Quantity 2000 
S8050D TO-92 General Purpose NPN Transistors 20 Pcs 
MPS2907A General Purpose PNP Switching Transistors 50 Pcs 
2N3906 3 Pins General Purpose PNP Bipolar Transistors 50 Pcs 
A92 Through Hole General Purpose PNP Bipolar Transistors 100 Pcs 
2N3906 General Purpose 3 Terminals PNP Bipolar Transistors 100 Pcs 
2N5551 DIP General Purpose NPN Bipolar Transistors 50 Pcs 
20 Pcs General Purpose DIP PNP Bipolar Transistors A92 
25 – 2N3904 NPN GENERAL PURPOSE .2A/40V TRANSISTOR 
S8050D NPN TO-92 General Purpose Transistors 100 Pcs 
20 Pcs 2N5551 General Purpose DIP NPN Bipolar Transistors 
20 Pcs General Purpose DIP PNP Bipolar Transistors A92 
2N5551 DIP General Purpose NPN Bipolar Transistors 50 Pcs 
20 Pcs A42 TO-92 General Purpose NPN Bipolar Transistors 
2N3906 3 Pins General Purpose PNP Bipolar Transistors 50 Pcs 
100 pcs. BC817-25 BC817 General Purpose NPN Transistor 
100 pcs 2N3904 NPN General Purpose Transistor 
100 pcs 2N3906 TO92 PNP General Purpose Transistors 
100 Pcs General Purpose Transistor SS8050 SS8050D TO-92 
100 Pcs General Purpose Transistor SS8550 PNP 
3 x 2N5087 PNP General Purpose Transistor 
30 Pcs Transistor S9012 STS9012, General Purpose PNP 
10 pcs. 2N3906 PNP General Purpose Transistor Ham Kit 
50 pcs. 2N3906 PNP General Purpose Transistor Ham Kit 
200 pcs. 2N3906 PNP General Purpose Transistor Ham Kit 
100 Pcs A92 General Purpose DIP PNP Bipolar Transistors 
50 x S9012 40V 500mA 0.625W General Purpose Transistors 
20 Pcs General Purpose DIP NPN Bipolar Transistors 2N3904 
A42 TO-92 General Purpose NPN Bipolar Transistors 100 Pcs 
20 Pcs 2N5551 General Purpose DIP NPN Bipolar Transistors 
50 Pcs General Purpose Transistor SS8050 SS8050D TO-92 
50 Pcs General Purpose Transistor SS8550 PNP 
100 Pcs General Purpose High Voltage Switch Transistor 60V 
20 Pcs General Purpose DIP NPN Bipolar Transistors 2N3904 
NEW 50 X 2N5401 PNP General Purpose Transistor TO-92 
NEW 50 X 2N5551 NPN General Purpose Transistor TO-92 
A92 Through Hole General Purpose PNP Bipolar Transistors 100 Pcs 
2N3904 General Purpose TO-92 NPN Bipolar Transistors 50 Pcs 
2N3904 General Purpose TO-92 NPN Bipolar Transistors 50 Pcs 
2N5551 DIP General Purpose NPN Transistors 100 Pcs 
A92 Through Hole General Purpose PNP Bipolar Transistors 100 Pcs 
20 Pcs MPS2907A General Purpose DIP PNP Switch Transistors 60V 
20 Pcs A42 TO-92 General Purpose NPN Bipolar Transistors 
A42 TO-92 General Purpose NPN Bipolar Transistors 100 Pcs 
A92 Through Hole General Purpose PNP Bipolar Transistors 100 Pcs 
2SD837-Q general purpose transistors- 100 lot- Panasonic- New 
50 pcs NPN General-Purpose Transistors 100mA 30V 300mW 
30x 2N3906 PNP General Purpose Transistor 3906 40V 0.2A TO-92 
2N5551 DIP General Purpose NPN Transistors 100 Pcs 
SALE New 10 pcs X 2N5088 NPN General Purpose Transistor TO-92 Free Shipping 
BC547C NPN general purpose transistors x 25PCS 
2N5551 DIP General Purpose NPN Transistors 100 Pcs 
2N3906 3 Terminals General Purpose PNP Bipolar Transistors 20 Pcs 
50 x S9012 40V 500mA 0.625W General Purpose Transistors 
MPS2907A General Purpose PNP Switching Transistors 50 Pcs 
50 pcs. BC849C BC849 General Purpose NPN Transistor 
10 x BC857B BC857 General Purpose PNP Transistor – Free Shipping 
100 x BC857B BC857 General Purpose PNP Transistor – Free Shipping 
A42 TO-92 General Purpose NPN Bipolar Transistors 50 Pcs 
50 x S9012 40V 500mA 0.625W General Purpose Transistors 
20 Pcs MPS2907A General Purpose DIP PNP Switch Transistors 60V 
500pair Transistor 2SCA1015 2SC1815 ( C1815 A1015 ) GR General Purpose Toshiba 
TO-92 General Purpose DIP NPN Transistors 2N3904 100 Pcs 
MPS2907A General Purpose PNP Switching Transistors 50 Pcs 
S8050D TO-92 General Purpose NPN Transistors 20 Pcs 
100 pcs 2N3904 NPN General Purpose Transistor 
100 pcs 2N3906 TO92 PNP General Purpose Transistors 
2N3906 3 Pins General Purpose PNP Bipolar Transistors 50 Pcs 
100 Pcs General Purpose Transistor SS8050 SS8050D TO-92 
100 Pcs General Purpose Transistor SS8550 PNP 
NSC 2N4238 Switching and General Purpose Transistor in TO- 39 Metal Can, 25 pcs 
A42 TO-92 General Purpose NPN Bipolar Transistors 100 Pcs 
S8050D NPN TO-92 General Purpose Transistors 100 Pcs 
50 Pcs NPN General Purpose Bipolar Silicon Transistors 
2N3906 General Purpose 3 Terminals PNP Bipolar Transistors 100 Pcs 
A42 TO-92 General Purpose NPN Bipolar Transistors 100 Pcs 
20 Pcs General Purpose DIP PNP Bipolar Transistors A92 
What is the exact purpose of a transistor and how does it work?
Please explain simply.
Thanx in advance.
The purpose of a transistor is to control the flow of current.
How it works is a bit more complicated and different kinds of transistors work in different ways. Transistors belong to a family of materials called semiconductors. That is, they are neither conductors nor insulators. Conveniently, their properties can be altered electrically to allow more or less current to flow through them.
The two main types of transistors are bipolar junction transistors and field effect transistors. In each case, though, there are three leads. Two of the leads are for the current that is being controlled. The third lead provides a variable voltage or current that determines the current flow through the other two leads. A small change in the control current (or voltage) can produce a large change in the amount of current carried by the transistor.
Some transistors are designed to produce a change in output current that is in direct relation to the control current (or voltage). This type of transistor is used for amplification.
Other transistors are designed to produce a sudden change from non-conducting to strongly conducting within a very small range of the control current (or voltage). These transistors are used for digital circuits. That is, they go from a 0 (non-conducting state) to a 1 (conducting state) with essentially nothing in between. They are either on or off.