Treadmill motor is 180V DC, how can I reduce voltage from 240v?

[craigrobbo]

Hi all..

So I have spent an unhealthy amount of time (even the MRS is getting annoyed) on google trying to find out how the hell I get 240v mains to 180v.

I understand a bridge rectifier is needed to convert AC to DC, that's the easy but and then i can use a basic thyristor based controller to control the speed.

however without having a huge bulky transformer, is there any way to get the needed 180vDC?

I see many people on youtube just powering direct from mains via rectifier, however most videos are EU/US based where they are running 110v mains.

Thank you!

[phill05]

I have just done it with this off e-bay https://www.ebay.co.uk/itm/144092505139

HHD6-G 1200W Input AC220V 5.5A Max Output DC 0-220V Motor Speed Controller 50Hz £30.44

It works a treat stripped it out and fitted into my own case with power in and power out to motor with the pot I get the veritable speed.

Phill

[craigrobbo]

I have just done it with this off e-bay https://www.ebay.co.uk/itm/144092505139

HHD6-G 1200W Input AC220V 5.5A Max Output DC 0-220V Motor Speed Controller 50Hz £30.44

It works a treat stripped it out and fitted into my own case with power in and power out to motor with the pot I get the veritable speed.

Phill

Thanks Phill, how do you regulate it so it cannot output more than 180V?

[phill05]

I am no expert at this so you might like to get others opinion.
What I found was the output tested was only 200V and when I asked I was told the DC motor should handle +/ 15 to 20% so I tried it on the motor at half speed with the pot and took it upto max and it worked, I then put the lathe to work under normal turning work and it has been fine no problems at all.

Phill

[Muzzer]

It's not going to suddenly blow up if you give it 180.1V. If anything, 220V will allow it to run at a higher speed. I wouldn't worry about it but if you are concerned, you could limit the max speed setting by putting a resistor in series with the pot or just fit a mechanical stop so you can't turn the knob all the way round if you aren't confident with electronics.

[m_c]

180VDC motors are typically designed to be run from a pretty basic SCR/Thyristor based controller being fed 230VAC.
In the US you'll also find quite a few 90VDC motors, designed to run from 110VAC.


One thing to be aware off with basic SCR controllers, is the pot wiring is at half the input supply, so don't go sticking your fingers on the wiring with them powered up.

[craigrobbo]

180VDC motors are typically designed to be run from a pretty basic SCR/Thyristor based controller being fed 230VAC.
In the US you'll also find quite a few 90VDC motors, designed to run from 110VAC.


One thing to be aware off with basic SCR controllers, is the pot wiring is at half the input supply, so don't go sticking your fingers on the wiring with them powered up.

That sounds pretty dangerous haha!