Hi guys,
I am running a few small motors via arduino mega 2560 (using mosfet with diode circuit as a driver for each motor), and using 9 v battery via Vin pin to power motors and arduino. Everything works fine, just the problem is that the processor/microcontroller of the arduino heats up very quickly and it worries me a bit. What would be your opinions on this ?
Best,
h.
It is more likely the voltage regulator overheating. Show us how it is wired. Where exactly do the motors get their power from?
The chips are all OK up to about 125C, which is hot enough to burn you but fine for the electronics.
Sorry for late reply.
So this is how I patched it up (using 10k pot, 10k resistor, 1N4001 diode, FQP30N06L N channel mosfet 60v 32a )
At the moment ir runs like this and inteds to heat up a bit. Want to run 12 same dc motor and pot sets on this one mega 260. What are you thoughts?
gate-drain-source is the order of pins on any power MOSFET... Your diagram suggests you assume the
order is source-gate-drain, if so you are shorting your Arduino pins into the drain, which would account
for the severe overheating of the ATmega2560.
The microcontroller should only be rising a few degrees above ambient in normal use.
The drain is the centre terminal because that's the substrate (underside of the chip), and power
MOSFETs are vertical current flow, so the drain has to be substrate.
0-9volt on the analogue pin :o
Pot power should be connected to 5volt and ground.
I hope you don't use a 9volt smoke alarm battery to power the Mega + motor.
Maybe it's better to post a real picture instead of a Fritzing mess.
And as MarkT said, check your mosfet connections.
Leo..
MarkT:
gate-drain-source is the order of pins on any power MOSFET... Your diagram suggests you assume the
order is source-gate-drain, if so you are shorting your Arduino pins into the drain, which would account
for the severe overheating of the ATmega2560.The microcontroller should only be rising a few degrees above ambient in normal use.
The drain is the centre terminal because that's the substrate (underside of the chip), and power
MOSFETs are vertical current flow, so the drain has to be substrate.
Mosfet order being gate-drain-source. Could you suggest wiring/patching of circuit ?
Also, is it possible to power up arduino and all of the 12 motor/ speed control motor, from one power supply ? 9v, or maybe 3AA (4.5v via 5v pin) would be enough ?
Any help will be appreciated.
hdxn:
Mosfet order being gate-drain-source. Could you suggest wiring/patching of circuit ?
Huh? Get the pin out right or it cannot work.
Also, is it possible to power up arduino and all of the 12 motor/ speed control motor, from one power supply ? 9v, or maybe 3AA (4.5v via 5v pin) would be enough ?
Its possible, but very ill-advised. Keep motor supplies away from delicate electronics if at all possible.
A 9V battery cannot provide anything like the current needed for motors.
Anyway the first thing you need to do is disconnect everything from your Arduino and check you have
not blown the pins that were on that pot or the MOSFET, as you may very well have fried them.
MarkT:
first thing you need to do is disconnect everything from your Arduino and check you have
not blown the pins that were on that pot or the MOSFET, as you may very well have fried them.
So yeah, already checked the pins. All seems working fine.
Would it be possible to get an advise/sketch on how would it be the best way to wire up this motor speed control circuit with mosfet and one 4.5 (3AA batteries) power supply for motors and arduino itself without frying pins?
Don't connect the pins wrongly? Don't connect the Arduino analog pin to a 9V potentiometer.
Don't connect the arduino pin to the drain of the MOSFET, connect it to the gate...
I suppose the key point is check everything carefully against the circuit diagram before applying power.
You must have had a circuit to work from the first time?
MarkT:
Don't connect the pins wrongly? Don't connect the Arduino analog pin to a 9V potentiometer.
Don't connect the arduino pin to the drain of the MOSFET, connect it to the gate...I suppose the key point is check everything carefully against the circuit diagram before applying power.
You must have had a circuit to work from the first time?
Cool, so I rewired it like that (instead 2aa it is 3, so 4.5v), seems working fine, tho still wanted to ask you take a look, and see if this looks alright ? Also, I am putting 12 sets like that in parallel and all of them only powered with one 2aa power supply, bad idea or will it be ok ?
