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View Full Version : Advice please : Quick voltage and amps question + speed control



Fivetide
27-11-2016, 09:30 PM
Ok I have 3 x 18v 3a motors to run in parallel. I was thinking of using a 24v 10 amp battery charger..will I die ?
And can I add a potentiometer somewhere easily to it or do I need a PWM with pot?

Here’s what I was thinking:
10AMP 12V/24V HEAVY DUTY BATTERY CHARGER ELECTRICAL CAR VEHICLE VAN TRUCK LORRY (http://www.ebay.co.uk/itm/10AMP-12V-24V-HEAVY-DUTY-BATTERY-CHARGER-ELECTRICAL-CAR-VEHICLE-VAN-TRUCK-LORRY-/131568149701?hash=item1ea212a4c5:g:BxIAAOSw~gRVu2~ i)

Split the power to :
3 x UK New 12V-36V 3A DC Motor Speed Regulator Controller Switch Control PWM HHO RC (http://www.ebay.co.uk/itm/UK-New-12V-36V-3A-DC-Motor-Speed-Regulator-Controller-Switch-Control-PWM-HHO-RC-/152095041000?&_trksid=p2056016.l4276)

Then wire all 3 pots up to a bigger pot and use rubber soled shoes to test it all?
Now I know if I wired all 3 motors to the charger they will work (I’ve seen it on youtube) but no speed control.

Just seen Lee's post , wonder if I could run them off one of these.. ? LINK (http://www.mycncuk.com/threads/9786-Meanwell-SP-200-24-8-4a-Power-Supplies-CHEAP!?p=85707#post85707) Mean well SP-200-24 24v 8.4a PSU power supply battery charger

Or AC-DC Switching Power Supply Module AC 100-240V to 24V 9A Power Supply Board FK (http://www.ebay.co.uk/itm/AC-DC-Switching-Power-Supply-Module-AC-100-240V-to-24V-9A-Power-Supply-Board-FK-/332006594872) wonder if the FK stands for FUCK ! when it blows up and takes an eyebrow off ?

Brand new ang High quality
Input Voltage:AC 100-240V 50/60HZ
Output Voltage:DC 24V
Output Current:6-9A
Output Power:150W(Max 220W)

Thanks Five :)

magicniner
27-11-2016, 09:53 PM
Just use one PWM controller rated at the sum plus 15% or so to run all three.

Fivetide
27-11-2016, 10:03 PM
Just use one PWM controller rated at the sum plus 15% or so to run all three.

what abot the AC to DC feeding : 10-50V 40A PWM DC Motor Speed Controller CW/CCW Reversible Pulse Driver TE535 (http://www.ebay.co.uk/itm/10-50V-40A-PWM-DC-Motor-Speed-Controller-CW-CCW-Reversible-Pulse-Driver-TE535-/262521215361?hash=item3d1f7bd981:g:BLsAAOSww9VXhSK ~)

Specifications:
Working voltage: DC 10~50V
Sustained current: 40A
Maximum current: 60A
Speed range: 0%~100%
CW/CCW: Support
Output voltage: Load linear
Speed principle: Current regulation
Dimension: Approx. 110 x 78 x 38mm

??

A_Camera
27-11-2016, 10:12 PM
Ok I have 3 x 18v 3a motors to run in parallel. I was thinking of using a 24v 10 amp battery charger..will I die ?
And can I add a potentiometer somewhere easily to it or do I need a PWM with pot?

Here’s what I was thinking:
10AMP 12V/24V HEAVY DUTY BATTERY CHARGER ELECTRICAL CAR VEHICLE VAN TRUCK LORRY (http://www.ebay.co.uk/itm/10AMP-12V-24V-HEAVY-DUTY-BATTERY-CHARGER-ELECTRICAL-CAR-VEHICLE-VAN-TRUCK-LORRY-/131568149701?hash=item1ea212a4c5:g:BxIAAOSw~gRVu2~ i)

That is only a 24V/5A so it will not work, at least not with any significant torque, if at all. You get 10A out only if you flip the switch to 12V out.

No, you will probably not die if you connect it, but of course, no guarantee is given by me. Anyway, why would you buy that to run motors? I mean, as far as I know, lead battery chargers pulse the output, which means that you need to modify the charger to get constant voltage and current out of it, and based on your questions, you can't do that. Why not buy a proper power supply? OK, more expensive... but there is a reason.

magicniner
27-11-2016, 10:13 PM
It should work fine, I'm a big fan of component systems though, that way if one bit fails you replace it but at that price it's probably worth a punt on the integrated unit.

Fivetide
28-11-2016, 12:13 AM
That is only a 24V/5A so it will not work, at least not with any significant torque, if at all. You get 10A out only if you flip the switch to 12V out.

No, you will probably not die if you connect it, but of course, no guarantee is given by me. Anyway, why would you buy that to run motors? I mean, as far as I know, lead battery chargers pulse the output, which means that you need to modify the charger to get constant voltage and current out of it, and based on your questions, you can't do that. Why not buy a proper power supply? OK, more expensive... but there is a reason.

I thought it was 5 - 10 amps ? Anyway I rechecked the values and each motor pulls 1.7 Ah so I was thinking about 24v 5a 120w (http://www.ebay.co.uk/itm/222029680440) or I could go for the 24v 10A 240w ? (http://www.ebay.co.uk/itm/222029680440) there's only 5 difference. Couple that like magicniner suggested to the 10-50V 40A PWM DC Motor Speed Controller CW/CCW Reversible Pulse Driver TE535 and hopefully it will have the power.. what do you think ?

cropwell
28-11-2016, 01:56 AM
First of all, forget potentiometers. You would need f**cking great big wirewound ones to handle the power.

Also for 18v motors I would use an 18v supply. PWM controllers give you full voltage, but vary the on/off ratio. This means you get full torque, but the power is in bursts, which regulates the speed. If you are using 24v then you could burn out the motors.

I look forward to the time you show your balls to the forum !

Cheers,

Rob

A_Camera
28-11-2016, 12:45 PM
I thought it was 5 - 10 amps ? Anyway I rechecked the values and each motor pulls 1.7 Ah so I was thinking about 24v 5a 120w (http://www.ebay.co.uk/itm/222029680440) or I could go for the 24v 10A 240w ? (http://www.ebay.co.uk/itm/222029680440) there's only 5 difference. Couple that like magicniner suggested to the 10-50V 40A PWM DC Motor Speed Controller CW/CCW Reversible Pulse Driver TE535 and hopefully it will have the power.. what do you think ?

It's 12V/10A or 24V/5A you can not select the ampere, only the voltage. Get a proper power supply like this instead of a charger:

http://www.ebay.com/itm/272388436734?_trksid=p2055119.m1438.l2649&var=571328337865&ssPageName=STRK%3AMEBIDX%3AIT

You are better off with those than a battery charger designed for charging lead batteries.

Fivetide
28-11-2016, 01:23 PM
It's 12V/10A or 24V/5A you can not select the ampere, only the voltage. Get a proper power supply like this instead of a charger:

http://www.ebay.com/itm/272388436734?_trksid=p2055119.m1438.l2649&var=571328337865&ssPageName=STRK%3AMEBIDX%3AIT

You are better off with those than a battery charger designed for charging lead batteries.

Ok it seems I need to think a bit more about this.. this is what I'm trying to replicate for my Uncle. But we have managed to gather 3 x 18v 1.7aH drills so far between us.


https://www.youtube.com/watch?v=NyvOX991Yik

Clive S
28-11-2016, 02:31 PM
How about three steppers:whistle:

Fivetide
28-11-2016, 05:06 PM
How about three steppers:whistle:

Yeah Clive I have 3 Nema 17 high torque but I wasn't sure if running them constantly for 20 mins would be ok ?

Clive S
28-11-2016, 06:17 PM
Yeah Clive I have 3 Nema 17 high torque but I wasn't sure if running them constantly for 20 mins would be ok ?
Nema's can run for hours think router and 3d printers, they can also run very hot in access of 60C without problems.

They also have the better torque at lower speeds

magicniner
28-11-2016, 06:56 PM
Get the 24V PSU and a single PWM controller rated to run all three motors, check the specification of the motors for current draw, you've just referred to the motor ratings as aH (amp hours) which is a battery charge capacity not a motor current draw.
If you don't have one get a multi-meter so you can check voltages and currents once you have something to fiddle with.

Fivetide
28-11-2016, 11:18 PM
Get the 24V PSU and a single PWM controller rated to run all three motors, check the specification of the motors for current draw, you've just referred to the motor ratings as aH (amp hours) which is a battery charge capacity not a motor current draw.
If you don't have one get a multi-meter so you can check voltages and currents once you have something to fiddle with.

I might just plump for one of these and a travel adapter and when I have everything working flog it on fleebay again. Super 30V 5A 110V Adjustable Power Supply Precision Variable DC Digital Lab H6TG (http://www.ebay.co.uk/itm/Super-30V-5A-110V-Adjustable-Power-Supply-Precision-Variable-DC-Digital-Lab-H6TG-/222092558420?hash=item33b5bf8054:g:pxMAAOSwoydWryN D) Or keep it I might want to mess with other stuff later. If it saves me buying the wrong power supply at least that justified the purchase lol

A_Camera
29-11-2016, 08:14 AM
Yeah Clive I have 3 Nema 17 high torque but I wasn't sure if running them constantly for 20 mins would be ok ?

Sure it's OK to run them constantly for hours also, but you need a driver for each and a motion controller also. So it is a bit more complicated. Even if you don't want a driver for each motor, just want to connect all three in parallel it is a fair bit more complicated to do what you are showing in the video.

Clive S
29-11-2016, 09:23 AM
Sure it's OK to run them constantly for hours also, but you need a driver for each and a motion controller also. So it is a bit more complicated. Even if you don't want a driver for each motor, just want to connect all three in parallel it is a fair bit more complicated to do what you are showing in the video.Yes But if you had read the other post http://www.mycncuk.com/threads/10360-Powering-3-45Ncm-Nema-17-Stepper-Motor-2A-4-wire-%28not-CNC%29/page2 you would have seen that this has be discussed

magicniner
29-11-2016, 10:59 AM
and a motion controller also. So it is a bit more complicated.

http://hobbycomponents.com/motor-drivers/537-pulse-pwm-generator-for-stepper-motor-drivers

But not very complicated as the above linked product has already been suggested, it's as complex a motion controller as is required, as the occasional lost step isn't an issue one pulse generator could be used for all three drivers - Simples! ;-)

- Nick

A_Camera
29-11-2016, 11:10 AM
http://hobbycomponents.com/motor-drivers/537-pulse-pwm-generator-for-stepper-motor-drivers

But not very complicated as the above linked product has already been suggested, it's as complex a motion controller as is required, as the occasional lost step isn't an issue one pulse generator could be used for all three drivers - Simples! ;-)

- Nick

True, with that simple controller it is much better than three power drill motors. Also more torque even at slow speed.

Fivetide
29-11-2016, 12:40 PM
True, with that simple controller it is much better than three power drill motors. Also more torque even at slow speed.

I have ordered or already have everything for the DC and Stepper builds.
They both have merits :
The stepper build linked to an arduino program will be good for taking the roughed out semi-sphere to an unpolished perfect sphere. I can set the program to speedup gradually and shift the rotational direction. More torque is required because it tends to grab when rough.
But it takes more parts and is a more expensive build. You have to have 3 controllers , flexible adapters and chucks.
The cordless drill version is good for the high speed polishing where torque is not a huge issue, it can also be controlled with an arduino and has a built in gearbox / chuck. Its also a cheaper build, 1 power supply and a single controller. Bit more cooling needed if there is no built in fans.
If .. and I say if ! I get them both working I'll do a vid and some pics.

A_Camera
29-11-2016, 12:49 PM
Yes, the stepper solution is a bit more complicated and more expensive. BTW, rotation direction change with a cordless drill motor is very easy, just switch the polarity on the motor you want to change the direction. Looking forward to see the vid.

Fivetide
05-12-2016, 11:27 PM
Well it worked , thanks guys, pretty simple in the end with your help..anyway a vid .. sounds like a jet engine taking off lol :)


https://youtu.be/NI7uh68hIOk

magicniner
06-12-2016, 12:55 AM
Cool, good to see you have something running, now we just need to see them working on your spheroids ;-)

I know it looks wrong but the other options were worse! :D