Pages: [1]   Go Down
Author Topic: dimming leds with tip122 and voltage variable  (Read 833 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 5
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Im trying to dimming two LEDs in parallel with a power supply of 3-48V variable and 1.4A constants with a TIP122. If I use a 3.7V battery I have no problems, but the supply give me 48V and tip begins heating extremely, but leds only needs 3V. This is like transistor demands all power capacity. Im using a 2k2 resistor on the base.
any idea? thanks
Logged

Offline Offline
Faraday Member
**
Karma: 65
Posts: 2529
Now, More Than Ever
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Schematic?

[Draw it out on a sheet of paper, take a picture of that and include it as an attachment.]
Logged

"Hello, I must be going..."
"You gotta fight -- for your right -- to party!"
Don't react - Read.
"Who is like unto the beast? who is able to make war with him?"

Pages: [1]   Go Up
Jump to: