Results 1 to 15 of 15
Thread: variable resistor tool
-
22-01-2011, 09:22 PM #1
variable resistor tool
members,
I recently worked with a fella who produced out of a bag a variable resistor tool
in short it was used for replacing/tricking thermistors on AC systems.
he said after he found it in my pocket they were available on line, OK please give a clue where................................................................................
I have looked at making one as parts could be sourced from maplin RS ect but this box of tricks was just right for the job, croc clips/prongs and a twist selector for ohms
any clues on where to get one?
Paul
"KEEP IT COOL"
-
22-01-2011, 10:28 PM #2
Re: variable resistor tool
Variable resisitor tool?... is that the same as a 10k pot? If so they're available at RS, Farnells, and Maplins as you've seen. Does your mate sustitute the thermistors with a pot then trim the resisitance to match the thermistors design parameters, then measure the the setting value of the pot?
Last edited by chilliwilly; 22-01-2011 at 10:35 PM.
-
22-01-2011, 11:45 PM #3
Re: variable resistor tool
Hisuperswill.
I may have the wrong idea, but what I have is old fashioned by todays standards.
It is known as a decade box.
A search under that title may clarify?
GrizzlyLast edited by Grizzly; 22-01-2011 at 11:49 PM.
-
23-01-2011, 12:06 AM #4
-
23-01-2011, 12:08 AM #5
-
23-01-2011, 12:28 AM #6
Re: variable resistor tool
Hi superswill
the resistances I have come across are 10K, 8K, 5K, 3K and 2K for space temps and something like 180ohms on an oil temp. So best bet is to get one with a trim pot similar to what chilliwilly has suggested. That way with any sensor you can have control over the dead band of the switching too.
-
23-01-2011, 10:18 AM #7
Re: variable resistor tool
Hi Paul,
Is is something like these.
http://cpc.farnell.com/cebek/edu-005...box/dp/HK01092
http://cpc.farnell.com/tenma/72-7270...box/dp/IN04175The difference between genius and stupidity is that genius has its limits.
Marc
-
23-01-2011, 10:27 AM #8
Re: variable resistor tool
i made one from cpc catalogue if you need any help they have a good technical line
-
23-01-2011, 10:27 AM #9
-
23-01-2011, 10:30 AM #10
Re: variable resistor tool
Let me know if they work will you?
I was thinking of ordering one of them a few weeks back.The difference between genius and stupidity is that genius has its limits.
Marc
-
23-01-2011, 10:38 AM #11
-
23-01-2011, 12:25 PM #12
Re: variable resistor tool
Go for a 10 turn pot as a single turn pot will not give you the accuracy
-
23-01-2011, 02:33 PM #13
-
23-01-2011, 08:22 PM #14
Re: variable resistor tool
http://uk.rs-online.com/web/search/s...ubRange=Decade Boxes#breadCrumb
Not got one myself but got a mate who swears by his..
Ginge
-
05-02-2011, 08:34 PM #15
Re: variable resistor tool
Marc,
is working well, i went for the CPC one
a few extra "mods" later mind
see link:
https://www.yousendit.com/download/M...NmMyWGMwTVE9PQPaul
"KEEP IT COOL"
Similar Threads
-
Variable speed rotary compressor control
By NB34 in forum Air ConditioningReplies: 0Last Post: 04-01-2011, 03:07 AM -
Variable speed motor theory help
By Contactor in forum ElectricalReplies: 12Last Post: 17-05-2010, 05:24 PM -
Energy efficiency of air-source heat pumps with variable speed compressors
By BoardMan in forum FundamentalsReplies: 14Last Post: 27-01-2010, 02:32 AM -
Variable Speed Control
By O_E in forum Technical SpeculationsReplies: 12Last Post: 11-04-2008, 05:59 PM -
Variable Frequency Drive
By Samarjit Sen in forum Technical DiscussionsReplies: 13Last Post: 31-10-2007, 09:11 PM