Switch 240V 10A with a >1V DC signal

I was talking with Oliver on the phone today about my project and he suggested I start a topic here in the forum to get some much needed help.
I have a CNC router that runs a 240V 1.5kW spindle which is controlled by a VFD. The signal to from the router to the VFD is 0-5V DC.

What I want to do is use that 0-5V signal to turn on a 1.2kW dust collector. There are some options to trigger a relay at 3V or 5V, but I can’t find anything that will work from say, 1V.

Oliver suggested something but it was entirely over my head. I can solder things and hack around but my electronics knowledge is almost zero.

So that’s my project, hopefully some of you can help me figure out what I need to get this done.


Hi Cam,

Your best bet in this case would be to use a DC-DC boost converter to pull your 1 V DC output to an output that’s high enough to be able to trigger the relay required for your router. A board such as that which I’ve linked below should be suitable for that particular application.


These will need some modification in order to connect to the relay, but should be suitable for that application.

Core Electronics | Support

Thank you for the reply Bryce.

So I would use one of those powered by USB to switch a SSR?

Hey Cam,

Yep exactly, when the input of the DC-DC boost converter is within the input voltage specs, it will output 5V, which should be more than plenty to trigger the relay to “close” (quotation marks are just because you’re using a Solid State Relay!)

Hope this clears things up!

Tks Owen.
If I made an enclosure to house everything, is there an uncomplicated way to power this with 240V?
It would be much better than running a USB cable from somewhere.

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Hey Cameron,

You could certainly do that, although given the dangers of working with that high voltage I wouldn’t attempt to perform that modification. The best recommendation for this one would be to follow the processes that were outlined in the video below by Ivan Miranda to set that up. If there’s anything else that we can do for you please let us know!

Core Electronics | Support