Author Options:

how to control a dc motor from a cd-rom with an h-bridge RX-2B ? Answered

hi,, i'm new here and i'm new using arduino,,,  i have an arduino uno, and i have to make a project for a class in my university.i would like to know how to use a dc motor form a cd-rom, i have an h.bridge RX-2B, and i need to know how to control the direction of the motor with those components, i've found some information around, but using another h-bridge, so i'm not sure about the configuration of my circuit, i jus t need tha for the moment,,,  thanks?


frollard has a terrific amount of info above on H bridges, which would solve your problem for a DC brushed motor, but generally CD-ROM motors are brushless, which means you need a 1/2 bridge on each pole, which you control independently. How many poles are there in your particular motor?
An RX-2B is an RC receiver decoder. Without the transmitter chip (TX-2B) it's not much use. Have you been assigned to use these parts specifically? Can you put up some more information? Interesting problem though!

hey thanks for response,, about motor, it has two poles, what i want is to change the polarity to change the direction of the motor, i saw i need an h-bridge l293 or something like that, but i don't have one.
RX-2B is an h-bridge that i borrowed ,, so, this bridge is not useful for my problem???
I put some new picture of motor and the h-bridge,, thanks again for answer to my post, i'm really new in this and i don't know how to make the circuitry for this,, so if you can help me with it, i'll really appreciate it


I'm betting the cd-rom had an h-bridge on it to control this tray motor.

Either way, a quick search here on ibles shows LOTS of h-bridge options, circuits, and integrated chips.

OH OK- it's a TRAY motor, not the one that spins the disc. So yeah, an Hbridge should work fine. However, I don't think the RX-2B is an Hbridge, rather, I think it's a 5 function receiver chip intended for something like RC cars- it'll give you signals, but not motor drive current.

An Hbridge would be something like:

and here's how to use it:

an h-bridge is a group of transistors that acts like a double pole double throw switch...

by controlling the transistors so that 2 are + connections, and 2 are - connections -- by reversing the poles you reverse the turn of the motor. You have to take VERY careful precautions to make sure you don't ever allow the transistors to directly connect + to - (since they are capable of it) The drawing I attached is a DPDT switch, and the 2 armatures are physically connected so they move at the same time...but imagine if you connected Btop to A and Bbottom to C (transistors can do that since there is no physical restriction on how you turn them on and off) -- you would have a direct short from B-A, A-C, C-B and it would asplode.


thanks for the info... i understand better now how works an h-bridge,, but i need help to know how to use it, and make the circuit... up there i put some pictures of the motor,, thanks again for your reply