DC Motor Problem - motor automatically reverses direction then twitches back and forth

Thread Starter

pckroeger

Joined Jan 16, 2018
1
Hello everyone,

I have next to no knowledge and this is my first post so please excuse the ignorance and if this is not posted in the right section please let me know and I will move it.
I bought two cheap ripple effect party light off ebay for my girlfriends ocean themed party. It is basically a circuit board with a RGB led light, a dc motor which spins a plastic light diffusing disc to ripple the light via a small gearbox, cooling fan, IR receiver, and mode switch.
One light works perfectly, the motor spins the disc in one direction without stopping as it should. However, the other light has an issue with the motor direction. The motor will spin the disk but at the end of every rotation it will reverse direction for about 1 second, then the motor twitches back and forth for about half a second, then the motor continues to turn in the original direction. This happens at the same point on each rotation of the motor.
Does anyone know what is causing this and if/how I can fix it so the motor just turns in one direction non-stop as it should?

Thanks very much.
 

MaxHeadRoom

Joined Jul 18, 2013
23,369
Are these DC brushed motors? and if so what is the nature of the controller.
Is it possible to swap motors and see if the same occurs?
Max.
 

tranzz4md

Joined Apr 10, 2015
310
From what you describe, I suspect the "gearbox", or the "circuit board". I'm guessing also that the "IR reciever, and mode switch" are used to select from a group of display schemes. Because the abberation occurs at the end of every rotation of the unit driven by the gearbox, it is likely that the "circuit board" senses that position of the driven unit and changes the current supplied to the drive motor, (whether you've selected such action or not) as part of a programmed scheme.

Certain motors can be reversed without any change of polarity, some will "buzz" without noticeably rotating, but your description of the repetition and single revolution of the driven unit point toward switching of the power to the motor by a device intended to control it.
 

cmartinez

Joined Jan 17, 2007
7,372
Hello everyone,

I have next to no knowledge and this is my first post so please excuse the ignorance and if this is not posted in the right section please let me know and I will move it.
I bought two cheap ripple effect party light off ebay for my girlfriends ocean themed party. It is basically a circuit board with a RGB led light, a dc motor which spins a plastic light diffusing disc to ripple the light via a small gearbox, cooling fan, IR receiver, and mode switch.
One light works perfectly, the motor spins the disc in one direction without stopping as it should. However, the other light has an issue with the motor direction. The motor will spin the disk but at the end of every rotation it will reverse direction for about 1 second, then the motor twitches back and forth for about half a second, then the motor continues to turn in the original direction. This happens at the same point on each rotation of the motor.
Does anyone know what is causing this and if/how I can fix it so the motor just turns in one direction non-stop as it should?

Thanks very much.
Can you post a pic of the components in question?
 
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