Motor overload automatic reverse- please help spec/identify
Motor overload automatic reverse- please help spec/identify
(OP)
Hello,
I am working on a project that would benefit from a motor that automatically reverses direction upon overload or stall. An example of this type is attached. In the example, a novelty Christmas ornament "animator" plugs into a light strand socket, and drives a winch. The winch: 1. Pulls the cord in 2. The hook stops at the enclosure 3.The motor reverses and lowers the hook again. This cycle repeats as long as the motor is powered.
I'd like to find a scaled up version of this, but more importantly, I'd like some terms to indicate this particular motor type or feature for specification and research.
Thanks for any help!
-k
I am working on a project that would benefit from a motor that automatically reverses direction upon overload or stall. An example of this type is attached. In the example, a novelty Christmas ornament "animator" plugs into a light strand socket, and drives a winch. The winch: 1. Pulls the cord in 2. The hook stops at the enclosure 3.The motor reverses and lowers the hook again. This cycle repeats as long as the motor is powered.
I'd like to find a scaled up version of this, but more importantly, I'd like some terms to indicate this particular motor type or feature for specification and research.
Thanks for any help!
-k





RE: Motor overload automatic reverse- please help spec/identify
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: Motor overload automatic reverse- please help spec/identify
I did google using those and similar terms, but so far haven't found a great specification or search term matching a motor that operates this way.
I'm more looking for a motor intended to operate throughout its lifespan, rather than one with an emergency shut off or reverse system. I'd also like to avoid a micro controller or current sensing PCB if possible (as in the example, there is no PCB involved- it seems that an overload simply causes a phase shift and consequent reversing of the motor).
RE: Motor overload automatic reverse- please help spec/identify
Mount this motor on a reaction plate, restrained by a spring and two position detent. When the motor torque exceeds the setting and the reaction plate jumps to the other detent position, a double through switch may be operated by the action to energize the other winding and run the motor the other way.
Bill
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"Why not the best?"
Jimmy Carter
RE: Motor overload automatic reverse- please help spec/identify
There are elctronic systems that do the same thing - or electromechanical systems. If this is a volume application, you better look for a consulting engineer that can design it for you. That way, you can optimize every aspect. For a one-off or low volume application, I recommend Bill's approach.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Motor overload automatic reverse- please help spec/identify
I tried to get a closer macro pic (attached) to illustrate the simplicity. Looks like a simply a coil and a free floating permanent magnet. I'm not sure if you can see from the pic, but there is a tab attached to the radial magnet, and there is a free floating pinion with a corresponding tab. This allows the magnet to rotate about 350deg without contacting the gear tab which is driven by the magnet tab.
My thought is that because this is an AC motor, there is a phase shift that can somehow occur and allow the drive direction to change when stalled. It could be there is an internal mechanism/capacitor as you propose but from what I can see there is not.
Thanks for any further ideas!
-k
RE: Motor overload automatic reverse- please help spec/identify
http://www.google.com/patents?id=8ZMYAAAAEBAJ
I don't believe the method of reversal was cited in this thread, and I guess its an unusual type to describe for sourcing. I am going to see what I can find with this discovery, but for the time being wanted to post this for reference. I still wonder if this arrangement can be scaled up and/or found in production quantities.
Thanks!
-kevin