Small DC Motor

[johnJ123]

Hi I am working with a small DC Motor and would like to know if it is possible to use something small to make the motor pulse on & off when connected to the battery. Thanks very much!

 

[mramos1]

Hi I am working with a small DC Motor and would like to know if it is possible to use something small to make the motor pulse on & off when connected to the battery. Thanks very much!

Can you give more details? Voltage and current of the motor? Duration of the on and off.

 

[johnJ123]

Yes and thanks very much for showing interest. The motor is 1.5 to 3volts. The on and off could be every 1 or 2 seconds. My problem is I would need something small if it is possible at all. I have been reading up on electric components but am a real amateur at this. The motor runs on a AAA batery. Do you think anything exists which could do this. Thanks very much!

 

[maddog7]

So basically you need it when you power it to work 2 seconds, stop 2 seconds and so on?

 

[Sicarii]

what is the purpose of the on and off cycle? Typically Pulse Width Modulation (PWM)is used in DC motors as a speed control aswell as providing more effeciency. This is usually done at a much higher frequency then what your listing though, 10-30k cycles per second off the top of my head for a small DC motor.

If that is your goal a 555 timer circuit is probably what your looking for. A clear discription of what you intend to do with this motor is really needed to be of much more help though.

 

[Hero999]

You haven't said how much current the motor uses.

An astable multivibrator with a booster transistor will work.

The resistor values will depend on the frequency, duty cycle and current required by the motor.

Multivibrator - Wikipedia, the free encyclopedia

The values listed in Wikipedia are only good for about 0.5Hz and even with the booster transistor the maximum current will be too small for a motor, 3mA.

• R1, R4 = 10K
• R2, R3 = 150K
• C1, C2 = 10μF

For a 150mA motor divide the resistor values by 50 and multiply the capacitor values by 50.

 

[Dean Huster]

If the motor is low-powered enough, try putting one of those "blinker" lamps from miniature Christmas tree lights in series with it. But it'll have to be really low-powered, such as one of the motors used for the vibrate function of an old pager or cellular phone.

Dean

 

[johnJ123]

Hi Guys,
First, I am really appreciative of the reponses. Second, I am not too bright when it comes to all of this. I tried to draw a diagram and add a link. I am hoping that it makes things more clearer. I am amazed of the reponses I am getting and so thanks very much.

 

[johnJ123]

Hi sorry for the above message error. I am trying to insert an image. I am trying to find out if there is a component I can use to make a small DC motor turn on & off every 1 or 2 seconds.

 

[blueroomelectronics]

Of those choices the 2N5062 should work. You'll also need a flyback diode across the motor terminals or you'll eventually damage the transistor.

 

[johnJ123]

HI Blue, thanks very much for the advice. So would you say something like this would work to make the motor turn on and off every 1,2 or 3 seconds.

 

[blueroomelectronics]

Something like that, you'll also need a resistor on the base to whatever you're using to pulse the motor.
Another problem will be the voltage drop on the transistor will be around 0.7V
Won't work so well with a single AA battery.

 

[Hero999]

I posted a circuit which should do what you want, the following component values should work.

• R1, R4 = 180R
• R2, R3 = 2k7
• C1, C2 = 470μF

Here it is again.

 

[johnJ123]

HI Hero, thanks very much for the circuit. I tried my best to figure out your diagram. Is this anywhere close to what you mean. I hope you dont laugh too hard! hah.

 

[blueroomelectronics]

You're circuit won't work, you'll need some basic electronic skills to assemble Hero999's version.