What Toroidal parts do i need

[Christian Knuell]

Hi,

regulated power supply usually refers to linear regulators with typically small output capacitors.
Industrial switch mode supplies on the other side have quite large output capacitors or inductors and are perfectly suitable for stepper drives.

Christian

[JAZZCNC]

Industrial switch mode supplies

Industrial thats the key word here.!! . . . . . The problem with Unregulated switch mode supply with correct voltage and amp's is the cost. Industrial supplies that you can trust are very expensive and the Cheap chinese ones blow up for fun and are a lottery what you actually get out of them dispite what the ratings say.!
So Compared to Torodial built supply which you can taylor exactly to your needs regards V & A Good Switch modes are very expensive. Every machine I build use's custom built toroidal supply and I don't get any issues with blowing fuses. Only one time did I have any problem with a sensitive fuse tripping and changing the B rated fuse for a C rated eliminated the issue. Plus if this happens it's mostly on larger Va transformers not small ones.

Amxen Man:

You need 30Vac 2 x 15 transformer like this. Wire it in series as it's easier and neater IMO. If your not sure what we mean by series or parallel just ask it's simple.
http://www.airlinktransformers.com/c...nge/CM0300215/

3 x 4700 Caps rated 63V this will be the most common to find. Wire them in parallel so + to + to + to fuse rail and same for negative side. What you pay will depend on if you don't mind soldering or not. Clamp ones are expensive. See here.
http://uk.rs-online.com/web/c/passiv...984,4294466590

Then Simple 25A Bridge Rectifier. Something like this will do it's OTT but better that way.
Mount it on a piece of aluminium or heat sink. I find best thing to do is to mount the whole lot on piece of 3mm aluminium plate which then acts as a heat sink for the Bridge Rec.
http://uk.rs-online.com/web/p/bridge...fiers/8023240/

Regards Resistors to drain cap's then I use the NC contact of the relay which I use for E-stop circuit which then pulls in a Resistor to drain the Caps quickly.
That said you can get away without one if you like because the drives tend to drain the caps for you. Best to make use of the enable signal thou if your using this technique to avoid any chance of motors running on slightly while drives drain.

Other thing to be aware of with these supplies is that what you get out depends what you put in.? So if your mains supply is on the lower or higher side then you might not get exactly 42Vdc could be slightly lower or higher but you have enough safety margin so it's not an issue but don't be surprised or think you have done anything wrong if don't get exactly 42vdc.! (Little more wouldn't hurt anyway, your well safe @ 42v).

[amxen]

Thanks jazz i now have them all book marked. i have noticed you have visited this subject many times over the years and i respect your views on newbies and electronics. I still cant find a good newbie how to on this subject eg a step by step how to for people that can use a soldering iron and a mulitmeter but have no real electronics knowledge. I mean i can strip a combi boiler into it component parts and test each part to determine if its working or not. I can test resistance on a thirmister at a given temp , test continuity on a gas valve . but im not clued up enuf to go at this with out a thought for safety ,even thow its more than likely going to be easy. Is there a good how to on the net. iv been looking all day ?