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Topic: Have Arduino uno got enough current for vibration motor ? (Read 13353 times) previous topic - next topic

jeolex

I have a vibration motor which is run with 2.5-3.5V, max current is 120 mA and motor resistor is 29 ± 6 ?.

So I have a project which contains LCD, phototransistor, IR LED, some buttons, potantiometer and vibration motor. I dont have a idea about that arduino uno's electric current is enough for this project. I know that digital pin max. current is 40 mA, is it also valid for 3.3V pin and 5V pin ?

Thanks.


JimboZA


Is 120mA more then 40mA?



Read the OP's question again....

is it [40mA] also valid for 3.3V pin and 5V pin ?
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steinie44

Quote

is it [40mA] also valid for 3.3V pin and 5V pin ?

So.........

JimboZA

So? He knows 120 is too much for an i/o pin, but is asking if it's too much for the power supply pins.
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
Dr Perry Cox: "Help me to help you, help me to help you...."
Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

fungus


I have a vibration motor which is run with 2.5-3.5V, max current is 120 mA and motor resistor is 29 ± 6 ?.

So I have a project which contains LCD, phototransistor, IR LED, some buttons, potantiometer and vibration motor. I dont have a idea about that arduino uno's electric current is enough for this project. I know that digital pin max. current is 40 mA, is it also valid for 3.3V pin and 5V pin ?

Thanks.


The 3.3V regulator on an Arduino Unu is one of these:

http://www.ti.com/lit/ds/slvs522n/slvs522n.pdf

Max current is 150mA
Advanced Arduino

fungus


So? He knows 120 is too much for an i/o pin, but is asking if it's too much for the power supply pins.


Hopefully he's not going to power his 3.5V motor from a 5V pin...

Advanced Arduino

steinie44

NO.
Not with all the rest of that stuff connected.

jeolex



Max current is 150mA



This answer what I have asked. Thank you. I guess 150 mA will not enough for my project. And I am new with arduino and electronic things. I research from websites and if I am wrong please correct me,

Can capacitor use for strengthen the current ? For example if my arduino's current is not enough for motor, so I use capacitor which is suitable for circle (I am not know yet). Am I right ?

JimboZA

What you need to do is power the vibrator externally to the Arduino, but probably control it from the Arduino via a transistor.

Have a look here for example.
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Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

jeolex

I have looked example. But I don't want to use external power. I just want to connect arduino to adapter and use my device. Is it possible ?

JimboZA


I just want to connect arduino to adapter and use my device. Is it possible ?


Seems you've already had a "no" to that question.
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
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Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

jeolex


JimboZA

The Arduino's a controller remember, not a power supply  8)
Johannesburg hams call me: ZS6JMB on Highveld rep 145.7875 (-600 & 88.5 tone)
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Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0

wes000000

#14
Aug 01, 2014, 09:39 pm Last Edit: Aug 01, 2014, 09:42 pm by wes000000 Reason: 1
Quote
The Arduino's a controller remember, not a power supply


This is true, but he specified his motor only used 120mA and the 3.3V regulator can source 150mA max. So why is that a no exactly?

I know it is not good to get close to your current capacity like that, but I would expect it to still work. And considering likely the rest of his circuity is using 5V regulator. And USB can source 500mA so he has no problem there (more current capacity yet if using an external supply).

And there is minimal harm in trying it. The worst thing that happens is the current draw is high enough to reset the Arduino. in which case it will become immediately obvious that motor will not work from Arduino 3.3V pin.

Quote
Can capacitor use for strengthen the current ?


Not to strengthen it, but it could be used as like a helping hand, so when the motor first starts to spin its initial current surge will come from capacitor not all from the 3V3 regulator. You would want a pretty large capacity capacitor though and it would need to be rated for the appropriate voltage.
"I have not failed. I've just found 10,000 ways that won't work." - Thomas A. Edison

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