Temperature controlled fan regulator
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.
You may also like:
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?
how to make it for 230v, 50hz, ac supply? also give its circuit digram
What modification required for 220V AC fan motor?
can anyone help me,what are the modifications that are needed to run a 230v,1.2A single phase motor.
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.
i have joined the circuit but the fan is working slow why?in the sheet there is no description of the voltages of fan
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
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.
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
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.
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.
thnx Seetharaman
should we modify inductor value for 230v ckt
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.
for what does PTC and NTC stands for?
and can we connect our fan directly without altering its wndg connection and capacitor
diuble all the values given for resisters and c3 capasitor u will get the circut for 230v regulator
what modifications are required for a 230v motor.,??., please reply ASAP.,
thanks in advance.
Is it an embeded system.any software needed?if want 2 b make this project in embeded system what software l b needed???
The circuit works well for a 110V fan can you please advice me What modification wii be required for 230V AC fan motor
What modification required for 230V AC fan motor
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
what is the rating of the motor???
What modification required for 230V AC fan motor
what modification have to be done to reduce 110 v power to a less value to make a mini model of this circuit