I'm working on a circuit to use a nano iot 33 to control power on and off of a 12v fan. The fan draws 1w and I have configured a 2n2222a transistor to switch the 12v power for the fan. The transistor base is connected to a digital pin (d13) w/ 1kohm resistor in line. When I first start everything up, it works and the fan starts when the digital pin is raised high (3.3v). However when the digital pin goes low, the fan continues (but at a lower speed/currrent). a 1N4007 flyback diode is connected between fan high and the transistor emitter as shown in the diagram. Where have I gone wrong with my circuit?
transfer the load to the collector
In your cartoon you show D2 grounded (pin 7) instead of pin 6 and that you are using D4 (pin 9) instead of D13 and that there is no power connection to the Arduino Micro. Is that the case?
Draw a schematic diagram of what you are trying to accomplish and label all the connections correctly. Post the code you are using.
This is a schematic diagram of what your cartoon depicts.
In your post, it's as if the police posted
"Have you seen this man?"
This may be more like what you want to try. Change D13 to D4 in your code.
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2N2222 ??? NOT NOT and NOT
Thanks @jim-p . Am I correct in reading your diagram that the diode is connected to the transistor collector? Currently I have the opposite (emitter).
Yes, basically the diode is across the Motor(fan) with the cathode (silver band) connected to the positive voltage and the anode connected to the collector.
You have the transistor in backwards. Notice how my transistor is turned around the other way
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thanks again for your help. It is working correctly now.
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Great!
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