Digest Number 203
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Posts: 46,084
Hey All:
Duncan said:
Subject: Switching 24V @ 50+A?
Hi all,
A colleague of mine is working on a project that requires
switching a high amperage DC motor on and off. Nothing high frequency -
just on and off. It pulls 50 Amps when running, but the surge at startup is
about 200 amps. I've used crydom hockey puck type relays for switching AC
loads up to 25A, but nothing DC. Is there a solid state solution for this?
All input appreciated, Duncan
DC loads like this have been traditionally switched with relay style contactors
(big and boy do they go "CLUNK" when you do throw them on line) that have been
specially designed for this purpose. An alternative to this would be to use
something like a high power IGBT or MOSFET transistor package. In either case,
you will then need to design some electronics to then interface these devices to
a stamp controller (been there, done that). The transistors can get pricey for
what you want to do though and depending on the Vce or Vds drop will probably
require heatsinking as well. If you want further info on this, let me know as I
have a background in variable speed drive and power electronics technology, and
I'll think about this throughout the day to come up with an alternative.
Gerry Shand
gerry_shand@t...
Duncan said:
Subject: Switching 24V @ 50+A?
Hi all,
A colleague of mine is working on a project that requires
switching a high amperage DC motor on and off. Nothing high frequency -
just on and off. It pulls 50 Amps when running, but the surge at startup is
about 200 amps. I've used crydom hockey puck type relays for switching AC
loads up to 25A, but nothing DC. Is there a solid state solution for this?
All input appreciated, Duncan
DC loads like this have been traditionally switched with relay style contactors
(big and boy do they go "CLUNK" when you do throw them on line) that have been
specially designed for this purpose. An alternative to this would be to use
something like a high power IGBT or MOSFET transistor package. In either case,
you will then need to design some electronics to then interface these devices to
a stamp controller (been there, done that). The transistors can get pricey for
what you want to do though and depending on the Vce or Vds drop will probably
require heatsinking as well. If you want further info on this, let me know as I
have a background in variable speed drive and power electronics technology, and
I'll think about this throughout the day to come up with an alternative.
Gerry Shand
gerry_shand@t...