Transformer is necessary for isolation!! Regarding high frequency topologies with isolation I think the following are the most common: 1. Phase Shifted Full Bridge. 2. Flyback. 3. Feed forward. 4. Resonant.
In theory they are rather simple but in practice even the smallest problem tend to explode the transistors. A used power supply is probably the cheapest. Nicklas Karlsson On Sat, 24 Jan 2015 08:49:20 -0800 Kirk Wallace <[email protected]> wrote: > Thinking aloud... > > I have been playing with an MA860H stepper drive which seems to work > well enough for my mill. > http://wallacecompany.com/ma860h/ > http://www.wallacecompany.com/machine_shop/Shizuoka/ > > I have an Antek toroidal transformer that is feeding 75 VAC to the > drive. The drive has an input limit of 80 VAC or 110 VDC. Although, to > feed three drives, I'll need a bigger transformer to supply 15 Amps or > more. I can use a 60Hz big iron transformer, but these are big, heavy > and expensive to purchase and ship. I could use multiple toroids, but > these are expensive. > > Then I got to thinking. What about a buck converter to convert mains > (120 or 240 VAC) to mains DC to high Hz AC to let's say 90 VDC? Or more > simply, pump the useful part of the mains AC into a large capacitor in a > way that maintains the DC voltage I need? This sounds a little like an > SCR circuit, such as a light dimmer, universal motor speed controller, > or SCR DC welder. This might be a way to leverage a cheap second hand > commodity device to a specialty purpose. (But keeping in mind that > common converters don't like their outputs switched.) > > So, what are some ways of feeding roughly 90 VDC or 70 VAC at 15 Amps to > motor drives from 240 VAC mains? > > -- > Kirk Wallace > http://www.wallacecompany.com/machine_shop/ > http://www.wallacecompany.com/E45/ > > ------------------------------------------------------------------------------ > New Year. New Location. New Benefits. New Data Center in Ashburn, VA. > GigeNET is offering a free month of service with a new server in Ashburn. > Choose from 2 high performing configs, both with 100TB of bandwidth. > Higher redundancy.Lower latency.Increased capacity.Completely compliant. > http://p.sf.net/sfu/gigenet > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ New Year. New Location. New Benefits. New Data Center in Ashburn, VA. GigeNET is offering a free month of service with a new server in Ashburn. Choose from 2 high performing configs, both with 100TB of bandwidth. Higher redundancy.Lower latency.Increased capacity.Completely compliant. http://p.sf.net/sfu/gigenet _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
