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Hi i was wondering what sort of relays that is good using with the 30A Electrolize with external relay option speedos and how big relays you could use,for example if i use a relay that can handle lets say 50A continiously, could the speedo be able to work with that or shall the external relays be rated at 30A continiously?
Technobots sell some that are sutiable
http://www.technobots.co.uk/en-gb/dept_31.htmlhttp://www.technobots.co.uk/en-gb/dept_31.html
Ed
http://www.teamstorm.comhttp://www.teamstorm.com
Thanks but if i take a 40A relay, can the rest of the speedo handle the current?
2.Or shall the relays be maximum 30A?
3.Is it the sort of relays that are in cars?
what motors you running?
Danny
Our 30A controllers using the relays provided with them were quite capable of handling peak currents of over 100 amps when trying to push the workbench through the workshop wall.
Sadly the 7.2v motors at 13V+ on a fully charged SLA tended to get a little warm ;(
regards
Tim
Ok but for how long did u try to push it? I havn´t built a robot yet but I will use some cheap 18V drillmotors for the drive, 900rpm, 3:1 reduction @ a 25cm/diam wheel and I want the speedos to survive the motors being stalled when pushing robots and such things. Because I´ve heard that some drillmotors get stall currents of about 40A and that would be quite dangerous for the 30A electrolize or?
No.
Electrolises can handle more than 30A once the relays are capable of handeling the current. I am using 15amp electrolises with 40amp relays without a problem.
Regards
Ian
OK so it is the relays that handles the current? Does that mean that i could use 100A relays on a small 15A electrolize without frying the speedo?
the FETs supply the current, the relay is used to change the direction. I think the FETs are capable of about 90Amps peak, the controller is mainly limited by the relays (hence why people change them).
Ah ok but what about the continious current the FETs can handle?