Temperature Controlled Fan Circuit.AVI

Using a 741 op-amp I'm testing the voltage drop across A 1k Ohm thermistor, TDC05C210 [RSR-21T1K]. Using a 1K Potentiometer and its wiper arm to set the threshold or temperature that were detecting for. I got it set to trigger off the red light and turn on a fan at around 80 degrees Fahrenheit or 26.66 degrees Celsius. The output turns on a NPN transistor which then allows power to be supplied to the 12 fan.

Category:

Education

Tags:

• Temperature
• Controlled
• Fan
• Circuit
• detector
• Led
• driver

[novax10]

if i use the 12V relay, it just on and off the fan but not controlling the speed of the fan right? do i need to use triac for this circuit??

[Howard10Howie]

@novax10

Ok, there are two ways of solving this that I see. The analog way would be to use three of these circuits, each one detecting for a different threshold preferably in incremental order. Each level would trigger a different relay adding more current to the motor and spinning it faster, faster, and faster. The second would be to use a programing logic and reading in an actual value off a sensor such as a LM34. Take a look at the Dragon Board videos I have posted.

[novax10]

how to control the the temperature using and 230V AC motor??can u give me some advice??

[Howard10Howie]

Yes, use this simple circuit, but on the out put use a 12Volt relay that can help you switch the power ON/OFF 230V AC, also take a look at the current ratings of the relay and make sure to use a back-draining diode. That would be the simplest way, let me know how it goes.

[Zues731]

Yes i would really appreciate it if you emailed me your schematic to this circuit. My email address is armandobargas54@yahoo.com Thank you very much

[coolguinithin]

can u please sent me the circuit diagram and the details of the components required to my mail...

my e-mail: nithin2sebastian@gmail.com

tanq in advnc..

[ysravani1]

please can u send me circuit diagram of this please....(srvn177@gmail.com)

[ninjatsu08]

i need its circuit diagram plz mail me...(fahad.tanveer8@gmail.com­)

[wakklaxons]

it is a good circuit..

may i hav the schematic and info if u dont mind??

really needs it..tq

wakklaxons@yahoo.com

[vivaishah]

hai, did u use 8051 ic ?