TheGrovesy
- Dec 19, 2011
- 6
- Joined
- Dec 19, 2011
- Messages
- 6
Hi all, I am a software engineer by trade but have recently started playing with some basic electronics.
I am creating a fan controller for a 12v fan which is driven by a microcontroller (arduino) and a transistor.
I successfully got this working with a 5v supply passing through the transistor (I tested this with a multimeter and saw that it was reading 5v for half a second and 0v for half a second, as programmed).
Great i thought, now lets try it with 12v (without the fan) and with a puff of smoke the transistor was dead!
Now i assume this has happened because there was no resistor before the transistor causing all 1.7A to pass through the transistor, is this correct? Below is an illustration on my setup.
Flickr Link
Also, will there be an issue having two different power sources? This wont be true for the final pcb, but as a mock up the arduino is powered by the USB on the PC and the 12v is coming from a variable power supply.
Many thanks,
Chris
I am creating a fan controller for a 12v fan which is driven by a microcontroller (arduino) and a transistor.
I successfully got this working with a 5v supply passing through the transistor (I tested this with a multimeter and saw that it was reading 5v for half a second and 0v for half a second, as programmed).
Great i thought, now lets try it with 12v (without the fan) and with a puff of smoke the transistor was dead!
Now i assume this has happened because there was no resistor before the transistor causing all 1.7A to pass through the transistor, is this correct? Below is an illustration on my setup.
Flickr Link
Also, will there be an issue having two different power sources? This wont be true for the final pcb, but as a mock up the arduino is powered by the USB on the PC and the 12v is coming from a variable power supply.
Many thanks,
Chris
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