Author Topic: PMDX-407 Impeadance  (Read 97 times)

KenWurtzel

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PMDX-407 Impeadance
« on: July 15, 2021, 01:07:51 PM »
I am having an issue with the PMDX-407 controlling the spindle motor speed. I am using a  DC Motor speed controller to drive a small 24V DC motor. The controller is supplied with a 100k pot and all works well with the pot supplied. When I connect the 407 across the reference voltage it drops from +11V to +6V.
I believe the PMDX-407 has a relatively low impedance for the Aref input. When I measure with an ohm meter between Aref and and Agnd it shows about 2.2k ohms.  Can someone verify this?