Looking for suggestions regarding an arduino pin controlled 12 vibemotor circuit.
I have 12 vibe motors (https://www.sparkfun.com/products/8449), controlled by 6 arduino pins, so 2 motors on 1 pin. each motor has a Pn 2222 npn transistor for switching on the motor. 1k r between arduino pin and transistor a #104 capacitor and 1N4001 Diode in parallel between the vibe motor leads and the transistor collector and +. this circuit x12 -http://www.learningaboutelectronics.com … ircuit.php
the ground and power portions of the circuit are in parallel for all 12 transistors.
I had this circuit running on a breadboard for a good long while maybe a month i transferred it to some perf board and put it into the project . it has since moved from one country to another and no longer works. the transistors seem to be fried. I am unsure how it was powered before. it is possible that it was powered off the arduino’s vin pin which would have delivered 12v. might this have fried the transistors?
it is meant to be run off of a separate 5 v 3.3 amp ac to dc converter w ground connected to the arduino for the arduino pins. Might replacing the transistors in this circuit return it to its former functionality?
Are there better ways to ensure the stability of a circuit controlling 12 vibe motors from 6 pwm arduino pins?
Thanks
It depends on your specific transistors. I would suggest reading through their datasheets to check for Maximum voltage. Although if it was working before, I don’t think that was the problem.
However, I’m confused as to why you’re using 12V if the motors can only handle 2.3V - 6V. How do you have them wired? I would imagine that they’re in parallel and that means they’re all getting 12V to the circuit’s source voltage. That would cause larger issues.
Someone else was demoing the project while i was out of town and i didnt have the 5v 3.3 amp power supply set up so i am guessing that they powered it via the arduino. That’s my only guess as to why some of the transistors have shorted
and yes all the transistors are in parallel.
I’ve since discovered some loose connections and after resoldering those most of the circuit is working however there are still a few shorted transistors. I am replacing those but I am curious about the stability of the circuit and i f there are more stable set ups? any advice re stability and possible causes of transistor shorting would be much appreciated
and the transistors are pn2222a. They can switch up to 40V at 1a so seems like if anything were going to go wrong it would be my motors getting fried? The motors are triggered by a sensor and scaled to that input so they are not on all the time and they are never getting the max power