DC Speed controller

[GoCreateParticipant @gocreate]

Hi

Anyone have any experience or comments using DC speed controllers similar to this.

I am looking to build a high throat bead roller and have a 24v DC motor and gearbox that will be suitable to drive the rollers, varialble speed would be a nice addition.

Usage is intermitant.

Any commment or recommendation appreciated.

Thanks

Nigel

[GoCreateParticipant @gocreate]

Cheap controllers anygood?

[Ian PParticipant @ianp]

No reason to suspect that it wont do what it says on the tin. I have bought other similar kit from HK and its always been well made and amazing value for money. Often the IC they use is identifiable as a standard part and the circuitry is a copy of the semiconductors application note, your listing is a bit less informative than I have seen but is probably very conventional and likely to work.

The speed controller you linked to is a ready made boxed product that will be easy to wire up.

Ian P

[Sub MandrelParticipant @submandrel]

My psychic powers tell me the box contains four power MOSFETS, a variable duty-cycle oscillator (in the old days a 555 but these days a microcontroller is cheaper) and a linear voltage regulator to power the oscillator.

It should work perfectly well.

Neil

[GoCreateParticipant @gocreate]

Hi Ian and Neil

Thanks for your reply, it gives me some confidence. is a small cost so very much worth a try.

Thanks

Nigel

[John HaineParticipant @johnhaine32865]

One ic with 4 legs – probably still a 555.

[Douglas JohnstonParticipant @douglasjohnston98463]

I have built my own dc controllers in the past based on a circuit in the book "Worshop Practice No.24" but looking at the price of this item it is now clearly cheaper to buy this than make one. I have bought a few electronic items from China and have never been let down and never had to pay VAT or extra charges, although in theory it is possible to be charged extra.British suppliers must weep at this however.

Doug

[I.M. OUTAHEREParticipant @i-m-outahere]

The IC is probably a switch mode controller chip .

How are you going to power it ?
The 30A rating may be momentary as those MOSFETs have small heatsinks so check your motor wattage .

Other than that it looks like a good unit .

Ian

[GoCreateParticipant @gocreate]

Hi

Thanks everyone for your posts

Ian, the motor is rated 8.6 amp 170 watts.

For this application the laoding on the motor should be reasonably light and will be intermitant short period usage. The gear box output shaft is 3rpm at 100 Nm torque, I will be gearing this down 2:1, I believe this will be more than enough for this application.

Thanks

Nigel

[Sub MandrelParticipant @submandrel]

I wouldn't be surpised is if it 30W continuous. The speed controller on my shunter has a single mosfet with a tiny heatsink – the single transistor is rated about 30A but the motor stall current is about 8A. Regardless of load it only get vaguely warm – the on resistance of mosfets designed for switching is tiny these days so as long as they are driven with a good crisp square wave with low impedance, they make very little heat.

Neil

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