transistor selection question

Hi,

I have a standard 2N4401 transistor.

a low voltage input on the Base pin.
Emitter pin to ground.
and a 15~20V input on the Collector pin with a load.

I have a 500mA draw from this circuit.

upon removing the transistor and applying the 15~20V directly to the load, I have 2A draw.

I want as much current as possible to my load. What kind of transistor can I use?
I need a transistor that can take high voltage input
(up to 100-200V and let up to 5A pass)

Alez87 said:

a low voltage input on the Base pin.

Click to expand...

More data!

Go to digikey.com or anyone that has parts.
In the search window "transistor". Results=more or less millions of options.
Click on "BJT single" =21,000 parts
Click on NPN hit Apply = 10,000 parts
Select 5 to 6A = 711 parts
Select 100 to 200 volts = 118 parts
Active only parts = 59 parts
"more filters" Choose gain 100 to 200 so we only see higher gain parts. =29 parts.

You might start out with "transistor Darlington". That will give you transistors with much higher gain.