Temperature controlled fan regulator

john July 8, 2009 34 Comments

Description.
This fan regulator circuit will automatically control the speed of your fan according to the temperature. Two thermistors (R1 and R2) are used to sense the temperature. The circuit works almost like the published here previously. Here the potentiometer is replaced by the thermistors. When the temperature is increasing the resistance of NTC thermistor ( R1) decreases and at the same time the resistance of PTC thermistor (R2) increases. At the same time, rate of change of the resistance will be different for R1 and R2.This action is similar to a potentiometer used in a conventional Triac based fan regulator. When the resistance is varied the firing angle of the triac changes and so do the speed of the fan.

Circuit diagram.

Notes.

The circuit can be assembled on a Vero board.
L1 can be a 70uH inductor.
C1 and C2 must be rated at least 200V.
C3 must be rated at least 600V.
Triac BT136 can safely handle up to 4A load current.
The two thermistors must be mounted as close as possible.

Categories:

Power Controller Circuits

Comments

sanjeev
March 16, 2016

anyone plz tell me whether using 5k PTC is necessary? can i use NTC instead of 5k PTC?

siddhu
March 12, 2015

i didn’t find 100k ptc,5k ptc where are they available and does the circuit work for 220v or any modification is needed

Ali
March 14, 2014

I didn’t find diac db2 is it possible to use other part (an alternative) and what is it ??

- pankaj
  September 9, 2014
  
  we can use db3 instead of db2 .
  it will work
  
ALI AMIR
March 14, 2014

I’m looking for diac db2 but I didn’t find itIs it possible to use an alternative and what is it..

- raag nilim
  June 14, 2014
  
  db3,db4 etc. Can be used or a mein bulb will work good
  
marco
March 12, 2014

May I know what is the use of C2 capacitor and the inductor? Thanks!

MEGHASYAM
September 30, 2013

could you please give the circuit of ceiling fan voltage regulator that used in our home appliances.our suppy is 230v,50hz.we will be very benifited and thankful to you if yo do this help.

ANAND DANDGAL
September 20, 2013

Why this type regulator not use in market.

thomas george
February 3, 2013

hi,
what is the use of the l1 and c3?
and in some websites it says db2 is schottky diode…
and how much the NTC and PTC cost in india?

ABHI
September 27, 2012

how to make it for 230v, 50hz, ac supply? also give its circuit digram

- Namle
  June 13, 2014
  
  Dear CT,
  I think that your circuit is very usefull, but in my area electric supply is 220V-50Hz, so what part I shoud change in the circuit? Pls inform me more data.
  
  Thanks in advance.
  
waqar
May 19, 2012

What modification required for 220V AC fan motor?

kabo mosenene
December 13, 2011

can anyone help me,what are the modifications that are needed to run a 230v,1.2A single phase motor.

seetharaman
December 1, 2011

Hi Akshay the fan should be rated for 110volt 60Hz.
Hi Zunair and kumar this is a simple speed regulator for the fan. The sensing thermisters should be in the air flow path to sense the air temperature. If the room is already quite hot the fan will be always running at high speed. if the temperature of the room reduces then the speed of the fan will reduce.

akshay
November 30, 2011

i have joined the circuit but the fan is working slow why?in the sheet there is no description of the voltages of fan

zunair sahhid
October 14, 2011

please can some one describe whole of this circuit .em quite new to these things so i cant really get that which bit is doing what…can some one help me out please.
regards,
zunair shahid

kumar
May 30, 2011

I have tried this circuit,I observed effect of with 10W lamp. It dims when we put cold object over thermistor and brightens when we remove it.But when i connect it to fan the change in speed effect is not much observable.I measured the resistance of thermistor in morning and at high ambient temp. it varies by 26K ohm to 65 K ohm. But it is found that fan kept on for overnight and due to self heating property of thermistor the fan speed remain high throughout.

diego
May 11, 2011

hola puedo cambiar los valores de los termistores por valores de 1k y colocar un potenciómetro de 150 k en vez de la resistencia de 6.8k. como se comportaria el circuito. no venden los termistores de los valores del plano. gracias

diego
May 11, 2011

buenas tardes en cali colombia se consiguen termistores máximo de 1000 ohmios ptc o ntc. pregunto si coloco un resistor variable de 150 kiloohmios en vez de la resistencia de 6.8 K puedo obtener un función similar? cual es su consejo. gracias.

Seetharaman
March 10, 2011

IHi Swapni lt is only a line noise filter it can be left as it is. Increase R3 to 22K or more till you get the min imum required speed.

swapnil
March 9, 2011

thnx Seetharaman
should we modify inductor value for 230v ckt

Seetharaman
March 8, 2011

hi swapnil PTC is a positive temperature coefficient component. NTC is negative temperature coefficient component. PTC The resistance will increase as the temperature increases. NTC is vice versa. You need not carry out any modification to the fan, in the place of existing regulator you can use the above circuit.

swapnil
March 7, 2011

for what does PTC and NTC stands for?
and can we connect our fan directly without altering its wndg connection and capacitor

SEBIN
October 21, 2010

diuble all the values given for resisters and c3 capasitor u will get the circut for 230v regulator

sameer
September 3, 2010

what modifications are required for a 230v motor.,??., please reply ASAP.,
thanks in advance.

Aasiya khan
August 6, 2010

Is it an embeded system.any software needed?if want 2 b make this project in embeded system what software l b needed???

madhavan
April 10, 2010

The circuit works well for a 110V fan can you please advice me What modification wii be required for 230V AC fan motor

- david ochoa
  December 31, 2013
  
  It’s the same I think, one for each phase.
  210 V to 254 V are actually two wire with two phases an inverse wave and are 105 to 127v (if this is mono-phasic, tri-phasic would be otherwise).
  Maybe you can install two circuits immediately after thermistors, one for each phase.
  There must be another more simple, but that it occurs quickly.
  
sethu madhavan
March 8, 2010

What modification required for 230V AC fan motor

john
January 9, 2010

hi,

I did try this circuit, but seems there is some problem in it. I double checked if all the parts are working…I don’t get any voltage variation in the output voltage.

Can you please halp me with this circuit.

Thanks in advance
john

amit
October 25, 2009

what is the rating of the motor???

Iftikhar Ahmad
July 25, 2009

What modification required for 230V AC fan motor

- SUHAIL GULZAR
  February 4, 2013
  
  what modification have to be done to reduce 110 v power to a less value to make a mini model of this circuit

Temperature controlled fan regulator

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