2N2222 TIP122 PWM and Outputs

superchargingmachine · Mon Jul 10, 2006 1:57 pm

In order to run PWM idle we have to use the more powerful TIP122 to handle to current draw. If I need to run a more powerful device on one of the output channels could I also swap out the 2N2222 for a TIP122 to accomplish this or is this too much current for the MS to handle? If yes, is this an issue for PWM idle?

Post by **jsmcortina** » Mon Jul 10, 2006 3:27 pm

The TIP122 is a power darlington transistor and will not draw any more power from the CPU. You can safely use it in place of a 2N2222A as a cheap upgrade. I find it easiest to screw to the endplate of the case and run three short jumper wires. The tab will need insulating.

James

superchargingmachine · Mon Jul 10, 2006 4:46 pm

So there is no risk grounding too much amprage through the board either? Sorry I only know enough to be dangerous!!

defiance · Post by **defiance** » Tue Jul 11, 2006 7:29 am

That's definitely a consideration... If you set up several outputs with tip122s and have them all controlling 5A continous loads, you'll start putting a strain on the ground wires and board traces...

Even then, though, you could just run a dedicated ground wire to the tips and you'd only be limited by the ground wire size.

superchargingmachine · Tue Jul 11, 2006 7:38 am

I think since jsmcortina is mounting his TIP122's remotely it makes sense to run a dedicated ground line and not run the ground for multiple high draw devices through the board. I hadn't thought of doing this but it makes a lot of sense.

Jon k · Post by **Jon k** » Wed Jul 12, 2006 11:47 am

I ran dedicated grounds for my VB921s and TIP122