Thread: ground isolation on VRM and PCM
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Unread 30-01-2015, 15:52
phestnes phestnes is offline
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Re: ground isolation on VRM and PCM
Quote:
Originally Posted by ozrien View Post
You cannot measure the DC resistance between the input ground and output ground, and expect a useful measurement, it will be high-z. The reverse battery protection will not allow this. This is true for both PCM and VRM.

The input ground and output ground of the PCM and VRM are not isolated.

Is there a problem that's preventing your robot from functioning?
It's just something I noticed while trying to connect a sensor. The sensor was being powered by the VRM, and read by the RS-232 port on the RoboRio (which ultimately wasn't working). That is what led me to wonder if perhaps the isolated ground reference would be at fault. Out of curiosity - why is there high impedance between the input and output grounds on the PCM and VRM? Is there a technical reason to do this?
Last edited by phestnes : 30-01-2015 at 15:56.