PDA

View Full Version : switch around 4A current through a transistor(NPN type) is it possible?



godslayer
03-18-2010, 06:25 PM
one small question... i want to switch around 4A current through a transistor(NPN type) is it possible?
i don't think 547 will be able to handle it.. any mosfets that i can safely use to fit into the same circuit without much modifications?
Please give me the number... and price...

vikas
03-18-2010, 07:02 PM
My fav is 2n3055 which goes for about Rs 3 a piece.

2n3055 - Bipolar Power NPN, 15 A, 60 V

akshay66
03-18-2010, 07:29 PM
Not sure but maybe some of them can do the work......

BDY20
BD121
BD123
Ad161
PNP3055
BDX18
OC26
AD149
AD162

Try and read the datasheet & 2N3055 would work fine.

akshay66
03-18-2010, 08:02 PM
One thing more why don't you buy a LED Driver.Maxim has a great range.LED drivers will make your work really easy search on google.I think you'll be needing 2Mhz of switching output of 20W to 35W as per your requirment & PWM or linear dimming is a must for dimming effect.Search on GOOGLE

godslayer
03-18-2010, 10:15 PM
thanks for the list people.. i already have a lot of complications in my hand.. i dont want to complicate it anymore.. try to understand akshay.. right now.. let me work on it.. (its a secret and it is planned to use ARP) i will post the details after the project is finished OR i am unable to fix it...:-P

godslayer
03-18-2010, 10:26 PM
@vikas.. are you sure it can be substituted for switching higher CURRENT in place of bc 547?well i have to make sum modifications like removing the resistors etc lower power voltage.. etc etc... I JUST WANT TO ADD MORE LEDS IN THE SINGLE ARRAY... LET ME KNOW if i am on the right path!

akshay66
03-19-2010, 12:01 AM
Yes, on the right path..........2N3055 would work well.Why do you need a 470 ohm resistor when you are supplying 3v??

How many LED arrays are you planning??

Which controller are you using for switching??

godslayer
03-19-2010, 10:37 AM
LED arrays=6
No of LEDS in an array around 40
Controller used=ATMEGA8
IF I NEED 470 ohm resistor?
please check my previous post.. i already said "well i have to make sum modifications like removing the resistors etc lower power voltage.. etc etc..."

akshay66
03-19-2010, 01:03 PM
Ok Sorry my fault.

godslayer
03-22-2010, 04:16 PM
My fav is 2n3055 which goes for about Rs 3 a piece.

2n3055 - Bipolar Power NPN, 15 A, 60 V
3Rs ones are chinese heard they get blown off easily... bell one costs around 13...

vikas
03-22-2010, 06:07 PM
Rs 3 ones powered my Amp through 3 years of engg :) ... so i bet they are good enough.

godslayer
03-22-2010, 06:10 PM
well might be.. lets see how the cheap ones perform on the use i am trying to put it in.. hope i dont have to run behind the BELL ones later on... :-)