I am working on a Neighborhood Electric vehicle...
Lots of issues, but the big one is the lack of a robust affordable controller.
All of the controllers in the "DIY" or "Hobby" environment use medium power Mosfets in a multiple Bridge format depending on if the are Brushed or brushless motors and the number of phases.
The Problem I am looking at at the moment is going from a packaged controller that run on 5.6-18v and getting it to drive power MosFets on 50+V rails.
Controlling the low-side of the bridge is easy, but the high side needs additional devices and "boost" circuitry.
I was wondering if optical isolators could eliminate all of the extra "stuff" as it could be connected almost directly between the rail and the gate with minimal other "Stuff" due to the isolation. Adding a similar isolator for the bottom side would allow you to "Separate" the power section and the logic section completely, possibly putting them on separate boards...
How practical is this?
For a controller I was looking at
http://www.onsemi.com/pub/Collateral/MC33033-D.PDF
I only see a handful of components, and nothing that requires special shielding, coil winding, or surface mounting.
The standard MosFet in most controllers is a
http://www.irf.com/product-info/datasheets/data/irfs4310.pdf
If I combined a controller like the above, and a few indestructible MosFets like
http://www.irf.com/product-info/hi-rel/hirelbrushlessdc.html#igbt
and Optically Isolate them on their on sub-assembly, how hard would it to build a affordable "robust" controller that could take the the mistakes that hobbyist throw at them... even if I do fry a MosFet, the control circuitry will be safe....
Looking for some guidance... Once I get close I was going to use one of the on-line board designers and build a protoboard...got to be cheaper than frying multiple controllers at $250 each.
http://endless-sphere.com/forums/viewtopic.php?t=2038&postdays=0&postorder=asc&start=0
Bob Sisson
Lots of issues, but the big one is the lack of a robust affordable controller.
All of the controllers in the "DIY" or "Hobby" environment use medium power Mosfets in a multiple Bridge format depending on if the are Brushed or brushless motors and the number of phases.
The Problem I am looking at at the moment is going from a packaged controller that run on 5.6-18v and getting it to drive power MosFets on 50+V rails.
Controlling the low-side of the bridge is easy, but the high side needs additional devices and "boost" circuitry.
I was wondering if optical isolators could eliminate all of the extra "stuff" as it could be connected almost directly between the rail and the gate with minimal other "Stuff" due to the isolation. Adding a similar isolator for the bottom side would allow you to "Separate" the power section and the logic section completely, possibly putting them on separate boards...
How practical is this?
For a controller I was looking at
http://www.onsemi.com/pub/Collateral/MC33033-D.PDF
I only see a handful of components, and nothing that requires special shielding, coil winding, or surface mounting.
The standard MosFet in most controllers is a
http://www.irf.com/product-info/datasheets/data/irfs4310.pdf
If I combined a controller like the above, and a few indestructible MosFets like
http://www.irf.com/product-info/hi-rel/hirelbrushlessdc.html#igbt
and Optically Isolate them on their on sub-assembly, how hard would it to build a affordable "robust" controller that could take the the mistakes that hobbyist throw at them... even if I do fry a MosFet, the control circuitry will be safe....
Looking for some guidance... Once I get close I was going to use one of the on-line board designers and build a protoboard...got to be cheaper than frying multiple controllers at $250 each.
http://endless-sphere.com/forums/viewtopic.php?t=2038&postdays=0&postorder=asc&start=0
Bob Sisson