Variable resistor ID. and sourcing.

[wombweller]

Hi all

I'm undergoing a restoration projects on a distribution panel used to distribute the time from a master to wherever is required The panel should have 4 variable resistors but three are missing and the one remaining is shot (not be me)

I'm not sure of the type so I include a photo of your ID. I am looking at purchasing the four resistors but I'm also unsure of where to obtain these so help required.

View attachment 63016

The only numbering on the one remaining resistor is 150 not sure if this is OHMS or not?

looking forward to the advice

 

[ericgibbs]

hi Mark,
Looks like a high wattage potentiometer, like these.

Isolate one end from the wiring and measure the resistance across the outer tags of the pot.

https://uk.farnell.com/jsp/search/b...arametricAttributeId=&prevNValues=2031+204281

 

[wombweller]

hi Mark,
Looks like a high wattage potentiometer, like these.

Isolate one end from the wiring and measure the resistance across the outer tags of the pot.

https://uk.farnell.com/jsp/search/b...arametricAttributeId=&prevNValues=2031+204281

Hi Eric

Gulp at the price of those!! Wonder where I might find secondhand ones that might match the orginal?

Cheers!!

 

[KeepItSimpleStupid]

You should be able to clean the area where the wiper wipes. With two leads disconnected, you can cleck the overall resistance of the reostat and see if it's damaged. Put a probe on one end of the reostat and follow the wiper. Once you know a portion of the value, you can determine the entire value.

The wiper sometimes lifts and/or the wiper gets less springy because it overheated.

 

[ericgibbs]

You should be able to clean the area where the wiper wipes. With two leads disconnected, you can cleck the overall resistance of the reostat and see if it's damaged. Put a probe on one end of the reostat and follow the wiper. Once you know a portion of the value, you can determine the entire value.

The wiper sometimes lifts and/or the wiper gets less springy because it overheated.

hi kiss,
The OP wants to replace 3 missing pots.

E.

 

[wombweller]

hi kiss,
The OP wants to replace 3 missing pots.

E.

Hi Eric
At least that's what I'm trying to do!! I actually need four.
There must be someone with a shed full of these exactly the same as I require.
See it's a restoration project and not just a repair.I will take some photos later to show.

 

[wombweller]

More photos of the Distribution panel

View attachment 63052View attachment 63053
View attachment 63054View attachment 63055
View attachment 63056View attachment 63057

You can see that someone tried putting too much juice through this.Where the plastic terminal blocks are there should be the same resistors as the one remaining damaged one.

This panel dates from around the 1950/60's so I would like to get it running as it used to.

Just need to find the same pots..

 

[ericgibbs]

hi Mark,
You could try winding your own, using nichrome wire on a ceramic former.

Does it need to be adjustable once you now the required value.?

 

[wombweller]

Now your asking!!

hi Mark,
You could try winding your own, using nichrome wire on a ceramic former.

Does it need to be adjustable once you now the required value.?

Hi Eric

Seems a long shot but if that is the way then why not try!!!

The idea behind the panel is to distribute the time throughout a building.The panel gets it's time base from the master clock through 'home loop 1' the remaining loops can have nay number of slave wired up in series to them.

The slaves that connect to this work on approx 330ma at 3v ish. The pot's are used to regulate this within each loop. There is an amp meter on the front panel and a plug that goes into each loop when setting up the pot's for correct milliampage .

Hope this explains... but please explain making these pots!!

 

[jpanhalt]

Those pots are a little more reasonably priced here, if you can find the value you need: https://www.ebay.com/sch/i.html?_fr...ramic+potentiometer&_sacat=See-All-Categories

In the US, several surplus stores also carry those pots. Where are you?

John

 

[wombweller]

Those pots are a little more reasonably priced here, if you can find the value you need: https://www.ebay.com/sch/i.html?_fr...ramic+potentiometer&_sacat=See-All-Categories

In the US, several surplus stores also carry those pots. Where are you?

John

Hi John

I'm in the UK.. I will search those thanks

 

[wombweller]

Those pots are a little more reasonably priced here, if you can find the value you need: https://www.ebay.com/sch/i.html?_fr...ramic+potentiometer&_sacat=See-All-Categories

In the US, several surplus stores also carry those pots. Where are you?

John

Thing is with this being a restoration project rather than a repair I want the pots to fit in to the original fixing holes on the panel.

 

[KeepItSimpleStupid]

The potentiometer mounting standard was a real standard for many any years. See: https://www.guitarpartsresource.com/electrical_pothardware.htm

 

[wombweller]

hi Mark,
You could try winding your own, using nichrome wire on a ceramic former.

Does it need to be adjustable once you now the required value.?

Hi Eric
Upon further investigation from people who have similar panels when the POT say '150' or '200' then they do measure at that in OHMS.