Remote control influenced by Shop Vac

woodchucker

woodchucker

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I have a cheap remote control (actually multiple) 3 of these units 2 with 2 channels and one with a single channel. All have seemed to work fine, one is dedicated to my DC, and the same controls a small shop vac on the other channel .. it works fine.

The other is in the metal shop. I thought the problem was my tool boxes, but after some playing it appears the shop vac motor is the cause...
The unit will turn on fine, but not turn off. If I unplug the shop vac, everything is fine. If I plug it back in, it does not shut without a fight.
Is there any filtering I can put on the shop vac plug to prevent interference.
 
You could try a 0.1uF to 0.47uF 250 VAC ceramic or AC film capacitor across the AC terminals of the motor. (I'm assuming 120 VAC vacuum and an AC motor.) Keep the capacitor leads insulated from shorting on anything and keep them as short as possible, a couple of inches maximum if possible. If it is a brushed motor then it is probably brush noise.
 
Reddinr said:
You could try a 0.1uF to 0.47uF 250 VAC ceramic or AC film capacitor across the AC terminals of the motor. (I'm assuming 120 VAC vacuum and an AC motor.) Keep the capacitor leads insulated from shorting on anything and keep them as short as possible, a couple of inches maximum if possible. If it is a brushed motor then it is probably brush noise.
Click to expand...
which way would be better toward the .1 or .47 in your opinion? Or doesn't it matter?
 
Can’t answer your original question, but this would explain the issues I started having with the remote power plug I used to have installed on my ShopVac: turned on ok all the time , but was hit & miss turning it back off; I ended up replacing it with an inline toggle switch that I could reach easier that the switch on the vac.
 
Try snapping a common-mode filter on the power cord (the snap-on type is easy for testing,
you can do something less visible if it works). Place near the motor, not the plug, to keep the wire
from being an antenna for motor noise.
clamp-on ferrite
 
I have had good luck with these AC line filters:


Are these RF remotes? If so what frequency do they run on?
 
I would try any value capacitor in that range as long as it has the proper voltage rating. witmore's clamp-on ferrite solution could help too, or possibly the line filter... It comes down to if the noise is radiated or conducted (or both).

If it is radiated right there at the motor then the capacitor will probably help.

If it is conducted out the cord then the ferrite or line filter can be very helpful. What happens with conducted noise is that the line cord can act as an antenna to radiate the noise. The closer to the noise source the better for any of these approaches.
 
It wouldn't hurt to take a look at the brushes on the shop vacuum. If they are on the way out,
they can generate a lot of unwanted hash(sparks too) and eventually damage the commutator
on the motor. Once brushes wear to a certain point, they cock a little bit in their holder and the
slight angularity difference will cause accelerated wear due to the fact that the brush is contacting
more than one spot on the commutator simultaneously. This causes sparking and generates
hash which can be heard on an AM radio. The RF generated could easily affect your controls.
 
Thanks all. @Reddinr thank you very much.

@cathead, that's probably why the situation has gotten worse. I'll take it apart and check. Probably the best way out would be to get a dust collector with a induction motor, so that I don't have a universal. But I don't have room in my metal shop.

Just took my Rigid apart the other day to check it's brushes, as it made a lot of noise. It's in a sound proof cabinet, so it can get some heat in there. I should have put the baffle on the top to vent more of that heat. Lots of black in the cabinet I assume from the brushes. But they were healthy. I cleaned it up, since it was a mess and all is good. The Rigid is much better designed than the Shop Vac. 2 of my shop vacs are the stainless 12 or 16 gal type. But they suffer like the lower end models.. junk switch and motor design. Funny how the whisper quiet is really not much quieter than my Rigid or Craftsman.. Just marketing. They diffused the exhaust port and now it's a "WHISPER" series.. without the ability to use it as a blower.
 
IMHO, the Shop Vac brand vacuums are junk, Rigids are much better at nearly the same price point. The Festool vacuums are the best, expensive but worth it if you use it daily.
 
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