looking for transistor

Comments

• upand_at_them Posts: 61

  2005-02-28 01:13 edited 2005-02-28 01:13

  You're just switching a current?· Check out the transistors section of Glitchbuster (http://glitchbuster.com/#xstrs).· I'm using the IRL520N MOSFET to switch 1.5 amps, but it can handle up to 10A.· Depending on your demands you might need a heatsink.
  
  Mike
• Matthew Posts: 200

  2005-02-28 04:01 edited 2005-02-28 04:01

  Mike, thanks for the tip. What was your application?
• upand_at_them Posts: 61

  2005-02-28 22:57 edited 2005-02-28 22:57

  I use the IRL520N to switch current to a nichrome wire.· It's a weather balloon cutdown to jettison the balloon remains once it bursts.· With 1.5 amps the MOSFET doesn't even get hot, but I'm only using it·for the 10-15 seconds.· And the gate is logic level; you can hook it right up to a Stamp I/O pin.· The only other component I have on it is a 47K pulldown resistor, to keep it switched off when there's no input at the gate.
  
  Mike
  
  ·
• Beau Schwabe Posts: 6,547

  2005-02-28 23:05 edited 2005-02-28 23:05

  Matthew,
  
  Just out of curiosity, where are you getting a 9V supply of 2A? ....Sounds odd
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔

  ---

  Beau Schwabe - Mask Designer III
  
  National Semiconductor Corporation
  (Communication Interface Division)
  500 Pinnacle Court, Suite 525
  Mail Stop GA1
  Norcross,GA 30071

  ---
• Charles Posts: 3

  2005-03-01 01:56 edited 2005-03-01 01:56

  How about the old standby pass transistor, 2n3055? It ought to handle that current quite well without a heat sink even.
• Matthew Posts: 200

  2005-03-01 05:53 edited 2005-03-01 05:53

  Mike, that sounds cool. I'm using it to ignite ematches for an ejection charge in a rocket! It should take less than half a second to burst.
  
  Beau, I'm getting the power from a Panasonic 9v N-6PT.
• Matthew Posts: 200

  2005-03-01 05:53 edited 2005-03-01 05:53

  Charles, I have noo idea. I'm just a newbe!
• upand_at_them Posts: 61

  2005-03-01 15:54 edited 2005-03-01 15:54

  If you're only switching on for a few seconds you can get away with the IRL520N without a heatsink.· Actually, any TO-220 case device is going to be able to handle the load.· The 2N3055 is a TO-3 case, which is a bit bigger, but it will still do the job.· The small plastic TO-92 case devices are only good for a couple hundred milliamps.· And the small metal can TO-18 devices are good up to about 800mA.
  
  Mike
• Jonathan Allison Posts: 96

  2005-03-01 16:56 edited 2005-03-01 16:56

  What about a TIP-120?
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  Johnny
• Matthew Posts: 200

  2005-03-07 03:00 edited 2005-03-07 03:00

  Mike, may you explain the schematics you used for that IRL520N MOSFET?
  
  Thanks,
  Matthew
• upand_at_them Posts: 61

  2005-03-07 03:09 edited 2005-03-07 03:09

  There's nothing to know about the IRL520.· Gate goes to the Stamp or PIC I/O pin, Drain to the current source that you want to control, and Source to ground.· And to keep the Gate from floating use a pulldown resistor, about 47K will do.
  
  Mike
• KenM Posts: 657

  2005-03-07 03:24 edited 2005-03-07 03:24

  Is this what you are looking for?

  

  

  IRL520.JPG

  352 x 305 - 28K

  IRL520.JPG 28.2K
• Matthew Posts: 200

  2005-03-07 04:19 edited 2005-03-07 04:19

  Okay! Thanks a bunch guys!
• upand_at_them Posts: 61

  2005-03-07 14:15 edited 2005-03-07 14:15

  Thanks for posting that schematic, Ken.· I don't have any drawing tools on my PC.· What did you use?
  
  Mike
• KenM Posts: 657

  2005-03-07 15:42 edited 2005-03-07 15:42

  Free pcb layout software and schematic drawing can be found at www.expresspcb.com
  
  k