Snubber for polarity switching motor drive

Thread Starter


Joined Apr 11, 2020
I have a door, opened and closed using a windscreen wiper motor. The polarity of the motor is switched with a relay. The problem I have is that the switches and connections fail frequently. I now realise this is almost certainly due to arcing.
I'm therefore looking at introducing a snubber to prevent this, only I'm not sure where and which way round to connect it, as the polarity changes.
The motor draws 6A at 12V.
Advice on the C value and R value would be appreciated too.UP-DOWN_CIRCUIT.png


Joined Mar 14, 2008
Thank you, I assume then that this works regardless of the motor polarity?
The diodes are always reversed-biased (or have zero bias) for either motor polarity, but will conduct for either reverse polarity transient when the motor is stopped.
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