Centroid Community CNC Support Forum

I'm not an electrical guy meaning that isn't what I do. I do understand why you should suppress coils, especially the larger ones, and I understand how the voltage spikes occur.

So, my question is how do I choose the proper suppressor when there are so many types. My contactor has a 24vdc coil, and I was going to purchase varistor for it, but now I am second guessing myself as to what I need. (paralysis of analysis)

So how do you choose a suppressor without getting into the weeds?

Clay

A typical DC coil "snubber will consist of a diode in parallel with a series-connected resistor and capacitor. There are purpose-made parts that contain all three. One of these is sold by Centroid in their web store. Using those would probably be your best option. Otherwise, Google "coil snubber", and spend a few hours reading how and why they work, and how to design one.

Regards,
Ray L.

RayL wrote: ↑Sat Jan 13, 2018 12:58 pm A typical DC coil "snubber will consist of a diode in parallel with a series-connected resistor and capacitor.

There are actually at least 3 different circuit methods for DC coils that I am aware of.

RayL wrote: ↑Sat Jan 13, 2018 12:58 pm One of these is sold by Centroid in their web store.

I've seen it. That one doesn't have a diode as you mentioned above, and how did Centroid choose that from the hundreds of thousands of other versions?

What I was really looking for a was Cliff notes discussion about why you choose one type over another. It seems google information is written by people that know nothing about electricity, or are PHD's and feel you need to understand the structure of an electron before you can discuss snubbers and their practicality.

Not trying to sound like an ass, although that is how I come across sometimes. <<<I think I will add this to my signature.

Clay

There is no simple answer. The snubber, ideally, matches the characteristics of the coil it's acting on. In most cases, a generic one will work just fine. It's only in extreme cases you should have to resort to custom designing one. In many cases, a simple reverse diode is all you really need.

Regards,
Ray L.

RayL wrote: ↑Sat Jan 13, 2018 11:35 pm In most cases, a generic one will work just fine. It's only in extreme cases you should have to resort to custom designing one. In many cases, a simple reverse diode is all you really need.

Regards,
Ray L.

Thanks, that's what I was looking for!

Clay