ello world,
I have a 12V 600RPM DC motor that I am going to connect to a breadboard. Can someone advise me what size(in ohms) potentiometer will suffice this motor? Also, need help with a power source.
Please advise,
Bull Engineer
(deleted)
Is there an Arduino?
Pots are low-power devices.
Typically, you'd connect the pot to an Arduino analog input. (See the [u]Analog Read Serial Example[/u].) Almost any value pot can work but I'd use something between 1K and 10K. Make sure you are using a regular (linear) pot, not an "audio taper pot".
The Arduino puts-out 5V, at 40mA (0.040 Amps) or less, so it can't directly drive a motor.
If you have a [u]motor driver circuit[/u] or an H-bridge motor driver you can adjust the speed with [u]analogWrite[/u].
You can use [u]map()[/u] to convert the 10-bit (0-1023) ADC reading to 8-bits (0-255) for PWM to control the motor speed.
Also, need help with a power source.
Check the current rating on the motor (Amps or milliamps). You'll need a 12V power supply (or battery) rated for at least the current required for the motor.
The voltage should be (approximately) constant, and the motor will only "take" the current it needs ([u]Ohm's Law[/u]).
If you use a battery, note that the mAH or AH (milliamp-hours or Amp-hours) is a battery life rating and it's only a rough guide to how much maximum current you can draw. i.e. A 1 Amp-hour battery will last (about) 1 hour at 1A or 10 hours at 100mA. ….You probably shouldn't pull 1 Amp out of a 1 AH battery, and it would only last one hour anyway so you'd probably want a bigger battery.
spycatcher2k:
I would say NONE, use a proper motor controller.
Thanks for your input, but why? is it not safe?
DVDdoug:
Is there an Arduino?Pots are low-power devices.
No arduino yet. I have one, but I plan on using it later in the project. I just want to use a pot to control the speed of my 12V motor.
(deleted)
And actually you can if the motor has brushes you can use a 5 watt rheostat(pot) to limit the current to the motor.
Paul
Paul_KD7HB:
And actually you can if the motor has brushes you can use a 5 watt rheostat(pot) to limit the current to the motor.Paul
Paul
I bought these motors. Are they able to be controlled without an arduino for testing phase?
bullengineer
it's a microcontroller, not a mega power source. Arduino > motor controller > motor
the microcontroller controls the motor controller which controls the motor
here's a hint: if the leads on the microcontroller are skinnier than the fuse for the motor, don't run the motor power through the microcontroller
BullEngineer:
PaulI bought these motors. Are they able to be controlled without an arduino for testing phase?
bullengineer
IF you can believe the question and answers from your link, then you indeed can control the speed without a controller. You just need the rheostat, as I suggested.
Paul
You could try this 10 Ohm 25 Watt rheostat.
The no load motor current is likely to be an Ampere or so.
The critical point there is “no load” (as a guess)
If you run it at 12V x 1A - we can guess roughly 12 Watts
A 5W resistor isnt going to last long... wirewound- a little longer.
Under load/stall conditions that curren will rise to maybe 3A
12 x 3A.... = xx watts
You do the maths.
Motor power stage, or Arduino & driver (capable of xx Watts)
I bought 4 of these motors and 4 of these potentiometers! any suggestions on power supplies/ how I should go about using the power supply? should I get a seperate power supply for each motor or should I use one power supply for all motors?
Please advise,
Bull Engineer
A single supply is fine so long as it can provide enough current for all 4 motors.
Steve
Lets put this in perspetive
You have a 200 hp motor in your car that you Will run at full power
What size brakes do you use to control the speed?
slipstick:
A single supply is fine so long as it can provide enough current for all 4 motors.Steve
Yes thats what my plan initially was. I want to supply enough current for all 4 motors using one power supply. Is splicing the wire into 4 outlets that lead to each (eventually)potentiometer a feasible solution? or will that mess with the current going to each motor?
Steve we have talked in other forums, youre always of great help(Karma incoming)
Bull Engineer
Draw a diagram of how you plan on connecting everything (a simple paper and pen picture is fine) and say exactly what power supply you are using and then you can get an accurate answer. Unfortunately phrases like "splicing the wire into 4 outlets" are way too open to interpretation.
In many ways it would be a lot easier with an Arduino. You're basically messing about using ancient technology for no real purpose that I can see.
Steve
slipstick:
Draw a diagram of how you plan on connecting everything (a simple paper and pen picture is fine) and say exactly what power supply you are using and then you can get an accurate answer. Unfortunately phrases like "splicing the wire into 4 outlets" are way too open to interpretation.In many ways it would be a lot easier with an Arduino. You're basically messing about using ancient technology for no real purpose that I can see.
Steve
Here is my basic schematic, Does this make a little bit more sense now?
Do your motors have only one wire?
Which pins of the pots are you using? (They usually have three.)
how to do that in that link