Potentiometer Advice

Thread Starter

Flam

Joined Apr 14, 2022
5
Hi Folks,

I got a cheap product with a dud potentiometer, the potentiometer is the speed control for a lathe. I am not an electronics person but I did (at the time when it failed) look at the rear of it and it's a 2w 4K7 unit. I searched online and could see 5ohm potentiometer versions, and I checked (via google) that the 5ohm part could be used and it seemed to be OK. Sometime passed (to today) and I bought a part having forgotten the previous research ( I suffer with some memory issues). Everything is the same on the part I ordered today except it's 10ohm. My questions are;

1. Will the 10ohm part work where previously a 4K7 part was used?
2. Do I need to add a component to make the 10 ohm part work? or,
3. Do I need to discard the part bought today for a different part?

Here's a link to the potentiometer I purchased today: https://au.rs-online.com/web/p/potentiometers/7377650

Or...
Should I just fit the potentiometer that I bought today and see if it works?

Thanks

Flam
 

Ya’akov

Joined Jan 27, 2019
5,666
Welcome to AAC.

Just to clarify up some confusion 10Ω and 10kΩ are not the same thing. A "4k7" resistor is 4.7kΩ or 4700Ω, 100x more than a 47Ω resistor. The one you bought is 10kΩ, not 10Ω. It is about twice the required resistance.

The closest thing RS seems to have in stock is this one which is 5kΩ only 300Ω too large. It has a good chance of working. You should not try to adapt the 10kΩ part, it brings all sorts of potential complications.
 

Thread Starter

Flam

Joined Apr 14, 2022
5
No it won't work, the old potentiometer is 4700 ohms, and your new one is too high 10,000

What else is controlling the lathe , can you take pictures?
Thanks for the reply.
I am not sure what you mean when you've asked its there anything else controlling the lathe. I have sourced an alternate, hopefully correct part here. https://au.element14.com/honeywell/...0798|&CMP=KNC-GAU-GEN-SHOPPING-SMART-MID-ROAS

But I'm not 100% sure.

If necessity is the mother of invention
The desperation is the father of destruction.
 

Thread Starter

Flam

Joined Apr 14, 2022
5
Welcome to AAC.

Just to clarify up some confusion 10Ω and 10kΩ are not the same thing. A "4k7" resistor is 4.7kΩ or 4700Ω, 100x more than a 47Ω resistor. The one you bought is 10kΩ, not 10Ω. It is about twice the required resistance.

The closest thing RS seems to have in stock is this one which is 5kΩ only 300Ω too large. It has a good chance of working. You should not try to adapt the 10kΩ part, it brings all sorts of potential complications.
Thanks you for the reply. I thought I'd found a better part in this https://au.element14.com/honeywell/...0798|&CMP=KNC-GAU-GEN-SHOPPING-SMART-MID-ROAS

The part you'd linked to kind of doesn't suit the application. I am looking for a panel mount 2W 4k7 single turn Potentiometer. With parts being listed in different formats it's hard (for me) to tell if a 5k part is the abbreviated version of the part I've provided the link for. Can you advise?

Thank You

Brendan

Harpo was my favourite.
 

sagor

Joined Mar 10, 2019
696
Thanks you for the reply. I thought I'd found a better part in this https://au.element14.com/honeywell/rv4naysd504a/conductive-plastic-potentiometer/dp/1020481?gclid=EAIaIQobChMIoLOH0cqU9wIVwRErCh0GvQCOEAQYBCABEgI22_D_BwE&mckv=_dc|pcrid|581351159199|pkw||pmt||slid||product|1020481|pgrid|133196505517|ptaid|pla-308179390798|&CMP=KNC-GAU-GEN-SHOPPING-SMART-MID-ROAS

The part you'd linked to kind of doesn't suit the application. I am looking for a panel mount 2W 4k7 single turn Potentiometer. With parts being listed in different formats it's hard (for me) to tell if a 5k part is the abbreviated version of the part I've provided the link for. Can you advise?

Thank You

Brendan

Harpo was my favourite.
Your link is the wrong part, it points to a 500k potentiometer. You want a 5k version. 5k vs 4.7k should make no real difference, both should work just fine.
 

Ya’akov

Joined Jan 27, 2019
5,666
Thanks you for the reply. I thought I'd found a better part in this https://au.element14.com/honeywell/rv4naysd504a/conductive-plastic-potentiometer/dp/1020481?gclid=EAIaIQobChMIoLOH0cqU9wIVwRErCh0GvQCOEAQYBCABEgI22_D_BwE&mckv=_dc|pcrid|581351159199|pkw||pmt||slid||product|1020481|pgrid|133196505517|ptaid|pla-308179390798|&CMP=KNC-GAU-GEN-SHOPPING-SMART-MID-ROAS

The part you'd linked to kind of doesn't suit the application. I am looking for a panel mount 2W 4k7 single turn Potentiometer. With parts being listed in different formats it's hard (for me) to tell if a 5k part is the abbreviated version of the part I've provided the link for. Can you advise?

Thank You

Brendan

Harpo was my favourite.
The part you've linked to is a 500kΩ potentiometer! That's 100x what you need!

Why do you think the part I linked to is not correct? It is a panel mount 5kΩ potentiometer. It is 3W because that's what they have in stock, but that doesn't cause any problem. The aluminum shaft can be cut to length.
 

Thread Starter

Flam

Joined Apr 14, 2022
5
The part you've linked to is a 500kΩ potentiometer! That's 100x what you need!

Why do you think the part I linked to is not correct? It is a panel mount 5kΩ potentiometer. It is 3W because that's what they have in stock, but that doesn't cause any problem. The aluminum shaft can be cut to length.
Yep I figured it was more than I needed but with some companies (I feel) you can't be sure, but it also speaks to my lack of knowledge around ohms labelling. The link you provided does suit insomuch that it fits the ohms requirement, but the shaft on the potentiometer is way different than the one I have, the kind I am replacing is the same form as the RS and Element14 potentiometers I previously linked to. I appreciate that might be considered a smallish thing, but I am genuinely surprised that I'm finding it as hard as I am to find a match, or a pretty close match.
 

Thread Starter

Flam

Joined Apr 14, 2022
5
Wow,

How in bloody hell did you find that our kid, I'm stoked. I'd scoured E14, RS components, and a few other resources and wasn't able to pin down a panel mount 2w 4k7 or 5ohm Potentiometer. Anything with the right spec was out of stock, as was anything that was the right spec on Amazon.

You're like the Columbo of the finding electronics stuff world and I'm very grateful for your efforts on my behalf.

Thanks

Flam
 

ThePanMan

Joined Mar 13, 2020
368
Hi @Flam. Good to have you on our website.

Perhaps a few terms need clarification:
K means "Thousand". So if something is marked 4K7 it means 4 thousand (and the next digit is the same as [point] 7). So 4K7 means 4.7K. Or as Yaakov said:
A "4k7" resistor is 4.7kΩ or 4700Ω
In electronics terms it's often easier to refer to something that may be in the thousands range to simply use the K to hold three zero's place. A 5KΩ pot is - and you've probably already gotten it - 5,000Ω.

Another thing NOT to be ignored is the 2W. W stands for Watts. If you get a device that is not rated for 2 watts, say it's only rated for 1 watt, it will burn up quite fast. On the opposite hand, if you went with a 3W device, it could handle "UP TO" 3 watts without burning out.

Sometimes people come to our website not fully understanding some of these things. If we point them out it's not that we think you're unintelligent, no. We just want to be sure you have the full picture. Also keep in mind some other NEWER person may come here and read your post and without a full understanding they could get hurt. None of us here at AAC want anyone to ever get hurt. So if you propose doing something that the rest of us see as dangerous - we'll speak up and speak up strongly. It's because we care. And don't want to be the ones responsible for someone hurting themselves with bad advice.

Like Dodgydave said; a 5KΩ (5,000Ω) pot will work very nicely. Very very close to the original spec, so you shouldn't notice any issues at all.
 
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