high power latching relay
Hi i try to find on internet for a latching relay for 100A and 100V DC resistive loads, all the ones i found are at 28V dc max
If you found something even if it is from china i would be very interested
A Digikey search found some but they're not latching and are $230.
You may have more luck looking for relays that have extra auxilary contacts and wire them in as a latching circuit. Not sure how much luck you are going to have finding 100amp DC rated contacts. Also what coil voltage are you requiring? Probably more information about what you are actually controlling and how it needs to operate (how will relay be turned on and turned off) might help us find you alternate solutions.Originally Posted by carmusic
Hi i try to find on internet for a latching relay for 100A and 100V DC resistive loads, all the ones i found are at 28V dc max
If you found something even if it is from china i would be very interested
Lefty
Measurement changes behavior
coil contact should be 24vdc or 12vdc i am controlling big transformers Rectifiers that outputs 100Vdc 100A maximum for cathodic protection
i have found a lot of 200A latching relays but always 30Vdc max
What are you switching that has a 10,000W load like that?
it is use to cut power for cathodic protection of pipelines
would it be possible to make this with mosfet since it is a resistive load. the reverse diode in mosfet will make troubles i think since i must have no polarity (must work in both ways and don't want the diode to conduct)
Here is a 200V DC @ 200 A DC relay:
DC Power Relays G9EC-1 | OMRON Electronic Components Web
It might be a good idea to include a safety factor on your current and voltage ratings.
As mentioned above, you would have to devise an appropriate latching scheme.
Maybe just get a smaller latching signal relay to energize the main relay coil.... shouldn't be a problem.
thanx i had found those but they are over 300$ each!!!
Yep, maybe you can find some used ones on eBay. A 10kW anything will not be cheap.
Big Amps cost Big Bucks!
What is your coil voltage?
Here is a 12v Power Relay for $6.50
12 VDC POWER SOLENOID | AllElectronics.com
Last edited by hotwaterwizard; 18th December 2008 at 05:50 AM.
Big Amps cost Big Bucks!
What is your coil voltage?
Here is a 12v Power Relay for $6.50
12 VDC POWER SOLENOID | AllElectronics.com
However it has a limitation: "50% duty cycle. 10 seconds on. "
It's designed to start a car engine, not for continuous operation.
Lefty
Measurement changes behavior
IGBTs
This page from a vendor says that their IGBTs can be used in parallel for higher current applications.
Would it be possible to arrange something that would accommodate your requirement for current in both directions?
International Rectifier - Product Information
Here is one item that appears to be adequate for 30A DC ....
https://ec.irf.com/v6/en/US/adirect/...D=IRGP50B60PD1
If the costs are acceptable, obtain several and see if they actually do what you want.
Maybe the company will give you some samples ....
Last edited by user_88; 18th December 2008 at 01:48 PM.
Power Switching in the Real World
There is an upcoming article about power switching using FETs and IGBTs in the January 2009 issue of Circuit Cellar Magazine.
The author says that his experience with paralleling IGBTs for higher current applications exhibits some unequal current sharing in such an application. ....with some units becoming hotter than others... and that he prefers FETs for parallel current usage.
It may be that the IGBT parts that are available at this time have improved, and would be worth a trial, or some sort of actual test before you reject their usage.... particularly if they are free samples.
There is supposed to be a follow up article in the CC magazine in February... regarding practical Power Switching cookbook circuits.
Last edited by user_88; 18th December 2008 at 05:28 PM.
if i do a switch with about 10 mosfet in parallel, could it work? will the current be share (i will take all similar mosfet with same rds)
can i put them back to back to make a swtich with no polarity?
if it is possible even with 20 mosfet it would be still be less expensive than a mechanical relay (minimum 200$ for a good one!)
What I was thinking was to try one bank of 5 or so, with a common gate signal, to be used for one direction of current, and a separate bank of the same number, in parallel, to be used for the opposite current direction. Then you have to think of some way to trigger each respective gate signal, when it is required. ....Not exactly sure how to do this .... maybe zero in on one or other side of the AC line polarity....
I don't think a back-to-back series arrangement would work. However, it looks like the IGBT specifications are robust enough to stand up to whatever is required .... just a matter of getting the gate signals to fire when you want them to....
... Are you thinking Mosfet or IGBT?
Last edited by user_88; 19th December 2008 at 01:13 AM.
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