Vibration Motor queston

I Have to calculate a resister for Vibration motor, is it calculated differently than LED's? Thanks!

Like LEDs, rumble motors have an operational voltage and current range where the rumble intensity varies depending on the amount of current you give it. The calculation is the same (BatteryV - motorV) / I

Using the example values of 2.5v - 3.5v @ 60mA max for the rumble motor and a battery voltage of 3.7v and limiting the current to ~80% of max to be "safe".

(3.7 - 2.5) / 0.05 = 24ohm
(3.7 - 3.5) / 0.05 = 4ohm

This gives a resistor range of 24ohm to 4ohm where the 24ohm will be provide a fairly weak (if anything at all) rumble and 4ohm should be fairly intense.

Ideally you would use a regulated power supply and multimeter to determine the actual voltage the motor needs for the given current. Alternatively you can experiment with different resistors within the rumble motors operational range. Avoid getting to close to the maximum range to be safe.

-Denzil

Quote:

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Originally Posted by Denz

Like LEDs, rumble motors have an operational voltage and current range where the rumble intensity varies depending on the amount of current you give it. The calculation is the same (BatteryV - motorV) / I

Using the example values of 2.5v - 3.5v @ 60mA max for the rumble motor and a battery voltage of 3.7v and limiting the current to ~80% of max to be "safe".

(3.7 - 2.5) / 50 = 24ohm
(3.7 - 3.5) / 50 = 4ohm

This gives a resistor range of 24ohm to 4ohm where the 24ohm will be provide a fairly weak (if anything at all) rumble and 4ohm should be fairly intense.

Ideally you would use a regulated power supply and multimeter to determine the actual voltage the motor needs for the given current. Alternatively you can experiment with different resistors within the rumble motors operational range. Avoid getting to close to the maximum range to be safe.

-Denzil

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Battery is 4.7
Motor is 3.0 volts
4.7 - 3.0 = 1.7 / 50 = 34 ohm
it is 95mA max
the online calculator says 47ohm, 1W

What battery are you running that is 4.7v? Li-ions are 3.7v each.

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Originally Posted by Silver Serpent

What battery are you running that is 4.7v? Li-ions are 3.7v each.

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Sorry typed it in wrong here, but did the math right on the calculator, 7.4V Li ion 2600 18650 PCB

Battery is 7.4
Motor is 3.0 volts
7.4 - 3.0 = 4.7 / 50 = .094 ohm
it is 95mA max
the online calculator says 47ohm, 1W

Keep in mind that you may not want the motor to run at full speed. I've found that it can cause too much vibration and sound. A potentiometer or multiple resistors may come in handy to find the sweet spot you are looking for.

Also, try to get a motor that's fully enclosed... The last thing you want is a spinning weight catching a wire and ripping things to shreds! ;-)

Quote:

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Originally Posted by setelf3of5

Battery is 4.7
Motor is 3.0 volts
4.7 - 3.0 = 1.7 / 50 = 34 ohm
it is 95mA max
the online calculator says 47ohm, 1W

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Correction for my my values the "50" would be in milliamps so you need to divide by 0.05

Quote:

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Originally Posted by Denz

Correction for my my values the "50" would be in milliamps so you need to divide by 0.05

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Quote:

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Originally Posted by TrypWyr

Keep in mind that you may not want the motor to run at full speed. I've found that it can cause too much vibration and sound. A potentiometer or multiple resistors may come in handy to find the sweet spot you are looking for.

Also, try to get a motor that's fully enclosed... The last thing you want is a spinning weight catching a wire and ripping things to shreds! ;-)

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Thank you Trypwyr, and Denz for your help.

Battery is 7.4
Motor is 3.0 volts
7.4 - 3.0 = 4.7 / 0.05 = 94 ohm
it is 95mA max

the online calculator says 47ohm, 1W

Trypwyr what would you suggest for two resistors? Forum says I can always use a higher resistor. So higher on the ohms, or higher on the Watts? or both?