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MickGeorge.
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November 9, 2006 at 9:52 am #22399
MickGeorge
ParticipantHi folks
Going to show my ingnorance here but you know what they say if you don’t ask then you don’t find out..
Noticed in a lot of fault codes and posts reference to a NTC and not sure what it means.. worked out thar pcb is printed circuit board but NTC has me baffled.. 😳
Thanks
November 9, 2006 at 10:13 am #194806gegsy
ParticipantRe: NTC – what is it and what does it do?
Hi Mick
Have a look here http://www.designinfo.com/cornerstone/ref/negtemp.html 😉Greg
November 9, 2006 at 5:16 pm #194807MickGeorge
ParticipantRe: NTC – what is it and what does it do?
Thanks gregsy
Quite a comprehensive article.. but basicaly a thermister that works negativly… presumably these are fitted to the tub or whatever like the ordenary themister and not part of the electronic board.
Mick
November 9, 2006 at 5:39 pm #194808gegsy
ParticipantRe: NTC – what is it and what does it do?
MickGeorge wrote:… like the ordenary themister and not part of the electronic board.
There are only two types of Thermister, namely negatve and positive.
1/ A Positive Temperature Coefficient (PTC) resistor is a resistor with a positive temperature coefficient. When the temperature rises the resistance of the PTC increases.
2/ A Negative Temperature Coefficient (NTC) resistor is also a temperature-dependent resistor, but with a negative temperature coefficient. When the temperature rises the resistance of the NTC drops.
HTH
GregNovember 9, 2006 at 6:04 pm #194809iadom
ModeratorRe: NTC – what is it and what does it do?
MickGeorge wrote:Thanks gregsy
Quite a comprehensive article.. but basicaly a thermister that works negativly… presumably these are fitted to the tub or whatever like the ordenary themister and not part of the electronic board.
Mick
The NTC is the ‘ordinary thermistor’ attached to the drum or more often these days slotted into the heater itself on washing machines.
Jim
November 9, 2006 at 9:07 pm #194810EFS
ParticipantRe: NTC – what is it and what does it do?
Look out for the temp sensor on Whirlpool ovens.
Described as NTC but if you test it it is PTC which may confuse diagnosis 😉Steve
November 9, 2006 at 10:41 pm #194811eastlmark
ModeratorRe: NTC – what is it and what does it do?
In this trade, NTC seems to be the universal term for any electronic temp sensing device whatever its operational function., these days.
November 10, 2006 at 12:14 am #194812Penguin45
ParticipantRe: NTC – what is it and what does it do?
eastlmark wrote:universal term for any electronic temp sensing device
They were called thermistors when I started………
Chris.
November 10, 2006 at 7:31 am #194813funkyboogy
ParticipantRe: NTC – what is it and what does it do?
does sound a bit more swav and sophisticated when you mention..
yes luv your main thermister is defo in a negative co-eficient situation and need replaced….that will be lots of money please…as oppossed to..ehhhh yes luv its your thermostat, oh is that all…
errr yeh…ps did they design them because it can talk to a digital board better than the old thermostst ????
allyNovember 10, 2006 at 8:14 am #194814Martin
ParticipantRe: NTC – what is it and what does it do?
funkyboogy wrote:ps did they design them because it can talk to a digital board better than the old thermostst ????
A thermostat has just one pre- set cut-off point whereas a thermistor’s (NTC) temperature coefficient (resistance) can provide a digital electronic control system dozens of temps from the same device!
November 10, 2006 at 9:07 am #194815Jackal
ParticipantRe: NTC – what is it and what does it do?
You guys need to get out more. 😀 😀 😀
Jackal
November 10, 2006 at 9:14 am #194816gegsy
ParticipantRe: NTC – what is it and what does it do?
Sssshhh…… the master doesn’t let us out 😥 😆
November 10, 2006 at 9:15 am #194817Martin
ParticipantRe: NTC – what is it and what does it do?
Jackal wrote:You guys need to get out more.
:rotl:
But it’s cold out there! (….or maybe my NTC is giving a false reading?) :hmm:
November 13, 2006 at 11:39 pm #194818andy2
ParticipantRe: NTC – what is it and what does it do?
Martin wrote:
funkyboogy wrote:
ps did they design them because it can talk to a digital board better than the old thermostst ????A thermostat has just one pre- set cut-off point whereas a thermistor’s (NTC) temperature coefficient (resistance) can provide a digital electronic control system dozens of temps from the same device!
Yep. The voltage value derived from the resistance is converted to an equivalent binary value in an analogue to digital converter on the microcontroller chip. This value can then be compared against a binary constant which is representative of the required temperature until the two values are approx equal.
The same technique is used on some program selector switches eg. GIAS
Each position of the switch selects various combinations of tiny on chip resistors which returns a unique value from which after A to D conversion the switch position can be determined by the microprocessor.
Andy 😀
November 13, 2006 at 11:47 pm #194819Penguin45
ParticipantRe: NTC – what is it and what does it do?
Gawd Andy………
What happened to the fixed value resistance comparator array? When the the thermistor value matched the fixed selected resistance value, off it went. I could get my head round that one.Chris.
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