Power supply required
|Mervyn Karwot||17/05/2019 15:17:33|
|9 forum posts|
Thanks Ian, I'll keep that in mind if plan A doesn't work.
Super thanks Dave for the theory and the link. As you can see, I'm not well informed about electric motors but your comments make things more clear and confirm that a 60volt supply would be ideal. I have a 60v Pulse Width Modulator with Reverser and this would make the system more controllable. Are 60v supplies much more expensive than 48volt systems? I couldn't find much on the web, even from China.
I only tried the leisure battery for a few seconds just to see if it worked before buying a proper power supply. I wouldn't run it like that for long. Perhaps it should be cruelty to batteries!!!
|4597 forum posts|
That should work fine. Up to 48V switch mode supplies are cheap because they're used for LED lighting. Being a common standard voltage, loads of them get sold. 60V is uncommon and likely to attract premium prices, but they do exist. (£39)
Presumably your 60V PWM controller doesn't have a built-supply? If you can't find an affordable 60V unit, I'd be inclined to try it with a more affordable 48V psu. It should work, just slower.
Don't forget to mount the PSU inside a ventilated insulated box - those power supplies have open terminals and are far from swarf proof!
Good luck - hope it all works out,
|Andrew Johnston||17/05/2019 16:20:56|
4780 forum posts
In addition 48V is a standard industrial distribution voltage within automation cabinets and the like, as well as for power over Ethernet units. The problem with 60V is that it is at the SELV voltage, so regulations get rather more onerous.
|Ian S C||18/05/2019 11:12:09|
7444 forum posts
An indication of what's around, my E bike has a Shimano battery pack, it's 36v 11,6 Ah Li ion, the size is 90 x 90 x 300, the weight is 2.67 Kg, the thing against it is the price which I'm lead to believe is about $NZ800 which is near enough to 400 quid. The bike has a 300W motor.
Ian S C
|Mervyn Karwot||18/05/2019 19:21:03|
|9 forum posts|
Thanks again for all the information and links. I have decided to get a 60volt DC supply and I have purchased a 0 to 60 volt adjustable supply direct from China through Banggood. Before anyone says anything, I have bought many workshop items direct from China through Aliexpress and Banggood and all have been high quality items. This one cost £37 with free postage but there could be a customs surcharge. I will get it in a few weeks and I will let you know the results
|Ian P||18/05/2019 20:26:18|
2145 forum posts
Whilst I was in the 'direct drive will never work' fraternity, I now think (based on what you have said) that your plan will work.
I would be interested to know more about the controller you are going to use, please can you say what make and model is it?
|Mervyn Karwot||20/05/2019 10:16:57|
|9 forum posts|
The controller I have has no name on it and the label says "DC9-60v Motor Controller20A" It is a pulse width controller with off, forward and reverse switch. I bought it a few months ago from an eBay seller in Hong Kong. It was working fine when I connected the motor to the test battery. It cost around £10.
The DC power supply I have just bought from Banggood is "AC 110/220v to DC 0-60V 8A 480W Adjustable Regulated Switch Power Supply"
My motor works with 1 to 4 ratio polybelt pulleys from the motor to the z axis handwheel. I have seen this setup on the internet before.
I hope this helps Ian.
|Swarf, Mostly!||20/05/2019 10:56:55|
|494 forum posts|
Added for historical interest: I believe that 48 Volts was also the voltage of the battery supply used by the old Strowger telephone exchange equipment. Lead-acid cells in glass tanks large enough to fall into!!!
|239 forum posts|
...and the 48V battery racks from a BT PABX made terrific end frames with their connecting bars for my work benches, superb pink pitch pine, black painted. " do you have to check those back in at base ?' - No squire, skip job, if you can make them disappear then help yourself" And the cells from 48V would have been an improvement on the 160off cells on the 240V cell-bank on a no-break power supply when it came to monthly maintenance, not to mention the 108 cells for the 80+/-80V
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