PMDX Forum

General Category => Parallel Port breakout boards, motherboards, and dedicated accessories => Topic started by: wbirnie13@gmail.com on January 19, 2019, 01:19:56 PM

Title: Max output current
Post by: wbirnie13@gmail.com on January 19, 2019, 01:19:56 PM

I would like to drive a LED with output 4. My LED has a max 20 mA rating. If I configure the resistor to allow close to this will the output be OK with this current.

Title: Re: Max output current
Post by: wbirnie13@gmail.com on January 20, 2019, 04:32:26 PM

I was thinking since I'm using a smoothstepper the max current for the output would be determined by the smoothstepper (32 mA). Would this be
the case?

Title: Re: Max output current
Post by: 12strings on January 21, 2019, 10:18:58 PM

I presume since you are posting on the PMDX forums that you are connecting a PMDX board to the SmoothStepper.  If so - which PMDX board?  If you look at the end of your PMDX users manual there is an electrical specs section.  Look for the "outputs" or "control outputs" lines.  That will tell you the max current that the boards can handle.  For example, the PMDX-126 can source or sink 16mA.

If you are connecting the LED directly to the SmoothStepper, then you need to ask the SS people.

Title: Re: Max output current
Post by: wbirnie13@gmail.com on January 22, 2019, 12:45:16 AM

Sorry I didn't mention I was using a PMDX-126. I also didn't realize the 126 was buffering the output. So 16 mA it is. Thanks for the reply.