Power for a hoist

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steamin10
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Power for a hoist

Post by steamin10 » Thu Sep 20, 2018 1:56 am

I have a small electric hoist that is a wall plug in, and geared to 500 lbs lift. It is a cute little thing, but the power board is blown out, and not available.

If I assume this thing is 12 volt, how many loaded amps should I anticipate??? I can get power strips for Led lights and other uses fairly cheap up to about 10 amp before the prices rocket. If t is another voltage how do I guess that? The motor is very small, about the size of my fist, so I dont think it very power hungry.

I am tempted to run a couple of jump wires form an auto battery to test the motor function, and see how it responds, if at all.

I am lost on this one, any ideas would be a help.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
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tornitore45
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Re: Power for a hoist

Post by tornitore45 » Thu Sep 20, 2018 5:06 am

Is there a sizable control circuit between the wall socket and the motor?
It would be unpractical and uneconomical to convert 120AC to 12VDC for a motor if a 120V motor could be specified.
My guess, not knowing much about, is that the motor is a universal motor, reversible and variable speed like is found in corded drills.
Mauro Gaetano
in Austin TX

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neanderman
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Re: Power for a hoist

Post by neanderman » Thu Sep 20, 2018 5:23 pm

If it is a 12v DC motor, and you do hook it up to a car battery, you can easily measure the amperage.
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John Hasler
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Re: Power for a hoist

Post by John Hasler » Thu Sep 20, 2018 5:29 pm

tornitore45 wrote:
Thu Sep 20, 2018 5:06 am
Is there a sizable control circuit between the wall socket and the motor?
It would be unpractical and uneconomical to convert 120AC to 12VDC for a motor if a 120V motor could be specified.
My guess, not knowing much about, is that the motor is a universal motor, reversible and variable speed like is found in corded drills.
I would be very surprised were that not the case.

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steamin10
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Re: Power for a hoist

Post by steamin10 » Thu Sep 20, 2018 9:48 pm

OK If I ring the leads on the disconnected motor, what should I be seeing for values??

This thing has a control board of some sort that may be a speed control. A diode of some sort is exploded and I cannot read the number or it would be changed out for giggles and fits. I was thinking it was a pulse control that would be for speed without losing torque.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

John Hasler
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Re: Power for a hoist

Post by John Hasler » Thu Sep 20, 2018 10:01 pm

You should see about the same resistance as an electric drill. Replace the popped diode with one rated at least 10 amps and 250 volts.

Bob D.
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Re: Power for a hoist

Post by Bob D. » Thu Sep 20, 2018 10:47 pm

I would pretty much say no way to your hoist having a 12vdc motor in it. My first thought on a burnt diode would be that is for the DC brake solenoid. If your brake is not releasing the motor isn't going to be happy.
Pictures would help. I have a lot of experience with hoists from 250 lb to 10 ton.

Bob
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tornitore45
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Re: Power for a hoist

Post by tornitore45 » Fri Sep 21, 2018 6:19 am

Has the "diode" two leads? If it has 3 leads is either a transistor or an SCR/Tyristor typical of waveshape chopping speed control.

The diode is blown but can you detect the band identifying the cathode? Assuming is a round body axial leads. If it is following John Hasler suggestion you have a good chance of success. Replace duplicating the original orientation.

If everything fails you can always rectify the AC with a simple bridge and use a 3 position switch Forward-Stop-Backward
Mauro Gaetano
in Austin TX

John Hasler
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Re: Power for a hoist

Post by John Hasler » Fri Sep 21, 2018 7:28 am

Good points. A 120 V universal series motor with no load will turn slowly when connected to 12 VDC. Odds are that the diode blew for a reason and so will just blow again, but replacing it is worth a try. If it is a universal motor it will run on AC. To reverse a series motor you must swap the leads to just one of the two series-connected windings. Thus a reversible universal motor will have four leads.

If it's a permanent magnet DC motor your screwdriver will stick to the side of it. A shunt-wound reversible DC motor will have four leads. One pair will show low resistance, the other high.

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tornitore45
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Re: Power for a hoist

Post by tornitore45 » Fri Sep 21, 2018 8:54 am

A simple trick to test equipment's suspected to blow again is to wire them in series with an old fashion incandescent light bulb, such as a 40W in this case.
Mauro Gaetano
in Austin TX

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steamin10
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Re: Power for a hoist

Post by steamin10 » Sat Sep 22, 2018 7:41 pm

I am dealing with some other issues today but rest assured I will continue

The little hoist was used as an aid in moving heavy 100-200 lb weldements to a positioning table for assembly. It is told to me that the hoist was grossly overloaded at times for various parts and failed. It came to me by way of the scrap bin at work. I will try to get some pictures up.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

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steamin10
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Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: Power for a hoist

Post by steamin10 » Sat Oct 06, 2018 10:44 pm

I have found a local Geek office that repairs radios and TVs. I am going to make contact Monday and see if they will look at this simple drive board. They should have little parts for electronics on hand or at least know where to get what is blown out there as since Radio Crap is gone I have no source. Add to that I do not have the technical knowledge to understand the function of the parts on the board, and I think it a better bet for success.

Plan B will be to auction off the remains and buy a cable hoist from Horror Fright, that will be adequate for my sporatic needs. The difference in price will be minimal to maintain function for my use.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

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