12V motor running at 60 RPM

Hi Esteban,

I would go for a stepper motor. See here.

Precisely timed electrical bursts increment the shaft a fraction of a revolution at a time. Typical revolution increments are 1.8º, 3.6º, 7.5º.

Digi-Key has some.

Drivers are fairly easy to make or purchase.

Mike

Couldn't agree more.....

You could also have a look at a servo motor.

If this is for a hobby project I would look around for abandoned pen plotters. I have for example a HP A0 plotter in my garage with two servos and rather quiet gearboxes waiting for a project I planed for my retirement (At the rate I am going now it will have to wait for my second or third retirement)

There is also nice small steppers in a stiffie drive (floppy).

Is the motor on the picture a DC motor with brushes?

You could try using PWM(chopped DC) to drive a DC motor? you may adjust the duty cycle to control the average speed. But this could be noisy too.

You can't simply slow down Your 5300 RPM motor, even if You could it wouldn't have any force left to do any work, i.e. turning pump...

I was playing with one of My gearhead motors in Feb. while making a YouTube Video, and got about 60 RPM from it purely by accident. It is supposed to run on 24V DC but I hooked it up to a small power supply from an extinct adding machine which only puts out 6V DC @ about 400ma.

Feel free to look at the Video, see if it is quiet enough.

It is very strong too, by adding a spool made from a 5/8" Bolt drilled for the shaft size of the motor, I used the same setup as a winch to lift My Camera, & it's Tripod 25 feet into the air while shooting another Video.

DC motor with brushed rotor varies its speed by varying the voltage. If the stator is not a permanent magnet but it has windings then that is called the excitation and by increasing/ decreasing the excitation current you can vary the torque at a given RPM set by voltage.

So useful would be a DC brushed motor with two sets of windings(I have found some in old car window wiper). The stator and rotor windings are usually connected in series and they need to get separated. The voltage applied at the rotor will give the rpm as said and by varying the stator current it may be possible to get a pretty good torque(so you need a current source; and be careful not to burn down the stator winding). This modification is needed because by simply lowering the voltage will decrease the power output pretty much, and the stator could get very hot if there is one.

If is a PM DC motor, with good magnets, you should still have a pretty good power output, but the motor could get hot or even stop if required almost rated power.

Regards.

Try to find an integrated motor with gearbox. those are less niosy than a separate gear.

Try a ready-made PWM feedback controller as may be used on better quality model railways: Gaugemaster <usual disclaimer> do just the right thing in a number of formats off-the-shelf, though the no-longer-made ECM Compspeed CA can sometimes be obtained secondhand (the CA is arguably the best thing that was ever made for this job). If the low inertia of the motor and the mechanical system it is driving becomes an issue for the feedback circuits, simply connect a 75Ω 2W resistor in parallel across the motor terminals.

This sort of equipment is designed to be fed from a 16-18Vac supply and has built-in overload protection.

Dear All, I have reviewed all your post. Seems to me that one easy option is use a worm gear, they offer 1:50 reductions, Then the speed motor could be controlled by a PWM circuit.

I have found a circuit for the same purposes that I was looking for, the control of a peristalit head. The circuit is offered in OEM mode by the manufacturer Watson Marlow, and in the manufacturers datasheet also is present the circuit diagram, and a part list, all the components could be purchased in my country to RS-Components.

But I need help with three issues

1- The electronic diagram have an integrated circuit (LM324), I am not sure if this is a PIC that need to be programed, or is a simple chip that could be wired to the other components.

2- I am not a really expert in electronics, so it is difficult to me create the PCB pists to etch in a copper plate. I can build the plate, I have done this before with good results, but I need the printed circuit board scheme. Anybody can help me with this stuff?

3. If no one can help me with point 3, also will be helpful another PWM circuit, but with PCB diagram.

This is the circuit board

and the information of that circuit is in the PDF in this link http://www.biolabware.com/instruction_leaflets.pdf

thanks!

It is all relatively simple components, no PICs or chips that need programming....

But unless you speak Spanish, you may get problems as I could only find stuff in Spanish on that site....

There are many circuits around, even simpler than this, using say a 555 chip. If you want some from me, you need to send me your normal email address over the CR4 email system....

My few circuits have been sent to your email address.

Thanks Andy, but that is soooooo weird! I already have the files that you sent me!. thanks you so much, but as I told you before, they lack of the printed PCB, and the PCB diagrams that you sent me (and I already have) lack of components list..

:-(

thanks you again.

Most of them are so simple, you can use veroboard or stripboard, you do not need a PCB.

You can download a free (I believe!) Stripboard designer from here:-

http://www.freedownloadscenter.com/Multimedia_and_Graphics/Misc__Graphics_Tools/StripBoard_Designer.html

or here with pictures:-

http://wareseeker.com/screenshot/stripboard-designer-1.01.exe/11554

The components are all marked, you can surely make your own list!!!

If I can help further, just ask.

You indeed can use electronics to control the motor by using a sized potentiometer often called a Variac-which is a product from a manufacturer having the same name.

The motor use and current draw under max load must be known before ordering.

Guest,

"sized potentiometer often called a Variac"

That makes no sense to me. I would never confuse the two.

Variable Autotransformers made by Variac are called Variacs because Variac got the recognition. They con't make sized potentiometers.

Variable Autotransformers are also made by Staco and who knows who else and people call them Variacs too.

They do not work with DC

A potentiometer is a resistance device used by feeding current from one end to the other and drawing off a desired Voltage potential from the moveable tap.

If you apply an electrical source to one end and no connection at the other and draw current from the moveable tap it is a Rheostat.

The potentiometer and Rheostat function with AC and DC.

Do you remember if the motor in question is DC or AC?

Jon

is 12V, DC

Thanks Esteban.

I knew that but Guest may not have considered it.

Jon

12VDC? or what?

Hi

I am Bernard, how can I reduce the speed of the motor from 4000 rpm to 60 rpm?