After the IC fan controller burned out by a voltage error I pulled it out to see what the motor coils were like.

They are so I think:

4 series coils, but I'm not sure if it's the 4 coils in series.

enter image description here Coils

enter image description here PCB

enter image description here Coils and fan

enter image description here Where the coils are not found, so I think the 4 are in series.

I was sad because I had burned out the PWM IC of the fan.

I analyzed the 4 coils well, only two filaments are soldered on the PCB, soldered two wires as you can see in the image and plugged in a common 12v 1a power supply, it turned and stopped, so I was making contact and removed quickly it spun a few seconds and stopped.

I try use PWM pulse with the Arduino and a transistor, I can see the pulse in the scope that uses the sound card in my desktop PC but the nothing happens if I connect directly in a source of 12v 1a simply tries to spin and stop.


In the Arduino I tried different intervals for the pulse from 50ms to 2000ms. Possible to use IC 555?

I need help because I do not understand much about electric motors, both dc and ac.


closed as off-topic by Chris Stratton, Voltage Spike, Finbarr, Lior Bilia, Sparky256 Jan 2 at 22:39

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – Chris Stratton, Voltage Spike, Finbarr, Lior Bilia, Sparky256
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  • \$\begingroup\$ include fan datasheet \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Dec 30 '18 at 17:41
  • \$\begingroup\$ Dc brushless model ksb0705hb, do not find datasheet. Sorry! \$\endgroup\$ – Gabriel L S Saraiva Dec 30 '18 at 17:59
  • \$\begingroup\$ What are you trying to do here? Figure out if it is damaged? Use a replacement without damaging it? Repair this? Run the bare motor with new electronics? \$\endgroup\$ – Chris Stratton Dec 30 '18 at 18:05
  • \$\begingroup\$ Methinks he was trying to fix a 5V fan that burnt out with 12V. Nice try but not a good question. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Dec 30 '18 at 18:14
  • \$\begingroup\$ It works in 12v without problems with a 220r 3w resistor but I inverted polarity and chemo ic, and I want to take advantage of the bearing that makes up the fan. Making it work again using injected pwm, in this case I used the arduino but nothing working. \$\endgroup\$ – Gabriel L S Saraiva Dec 30 '18 at 18:18

You need two H-bridges to do what you want to do. Wire the opposite coils together, and program an Arduino to switch the polarities at an adjustable speed, then give the fan a spin and try to adjust the switching speed to the point when it starts working. Look at the following schematic, voltage sources represent ends of H-bridges.

However, the Arduino controlled fan won't work nearly as well as the original one, as it needs to have some sort of speed feedback, which it doesn't, so spinning up is dumb luck. That's why you need to start it by hand and then the coils will pick up.


simulate this circuit – Schematic created using CircuitLab

  • \$\begingroup\$ I had not thought of that, great. \$\endgroup\$ – Gabriel L S Saraiva Dec 30 '18 at 18:26
  • \$\begingroup\$ But there are only 2 power wires and hidden circuits \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Dec 31 '18 at 6:41

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