Let's Make Robots!

DC

Can take simple Forward, backwards, stop commands.
Using a
My robot is a hacked RC car controled by an Arduino Duemilanove.   It has no sensors,  but I have left room on my chasis so I can add some more later when I feel … Read more

2 DC motors = 1 Power source = Two different Voltage and speed ?

So hey guys,

My twin-motor gearbox does not work good anymore.

First it was perfect, both had same speed, but now one DC works slower with higher Voltage ??

 

Motor A runs faster than motor B while motor B uses more voltage

MOTOR A backwards: 2.22V

MOTOR A forwards: 2.30V

 

MOTOR B backwards: 2.36V

MOTOR B forwards: 2.48V 

 

What might be the problem?

 

 

Questions about my Arduino Motor Controller

hi guys I have bought an Arduino and the Arduino Motor Shield from adafruit. The tutorial on Ladyada says that I can power a motor which has a capacity up to 36V. So i programmed my arduino to run a motor on M2 and then when I check the voltage supply over there its just 3.17 V. So how do I power a 5V motor. Also the amperage on the pin is only 0.49A whereas Ladyada says that I can power a motor upto 0.6A and 1.2A peak.Is everything correct with my shield. I have also read that I can power it from an external supply-How do I do that? How will it help me?

Thanks in advance.

Control DC motors with an ULN2803

I live in argentina and getting thing shipped here is a mess, so I try to use whatever is available here (which is rather limited) whenever I can.

So I was wondering since I haven't found any of the typical H-bridges ...is it possible to control DC motors (speed + direction) with a ULN2803? These I can buy here. 

If so then how would that setup be? Do I need any additional components? If so then which (transistors, resistors, diodes etc)?

DC motors from DAGU

I'm putting together an order at DAGU. But I need to be sure about one thing. The DC motors (items 12 and 13 in the LMR price list), are they GEARED motors? I presumed they were, but then I mailed Claudia and I asked: "Item 13 (dc motor) in the list: Are these motors WITH gears?" and got this answer: "The DC motor will not come with gears". However I think she may have misunderstood my question cause they do look like geared motors....

DC motor control with Arduino

Ok, so i had this running just a few days ago, but then when i tried to assamble it didnt work out for me. Now I cant even get this simple DC motor running from the arduino, or to be more precise; the motor will run at a very low speed. Connecting it directly to my two 1.5 batteries it will run at full speed, but when trying to control it from the Arduino it wont work for me.

 Here is my setup:

simple_dc_motor_sch.jpg

and the code is dead simple: