Controlling a 1.2kw motor

[craig_colliass]

I have a motor I want to use for a weapon on my next robot, and was wondering the best (cheapest way) to control it
It is a 1200w 24v Dc motor running off 2 hawker 12v batteries, all I want it to do is run full speed in both directions controlled by the Spectrum radio I was thinking of using 24v lorry starter solenoids but I think they are single pole so I would need 4 of them with two micro-switches and a servo. Can you think of a better way???

[woody]

Albright solenoids

http://www.albright.co.uk/http://www.albright.co.uk/

[leorcc]

Do these have 3 positions? forward/off/reverse?

[woody]

Yes Leo,

IF you use the paired option.

Paired Double Pole Single Throw for Motor Reversing... or
2 x SW61 on a common bracket with links for motor reversing.

Ends up in a configuration something like this...
http://www.teamonslaught.fsnet.co.uk/nonc_.gifhttp://www.teamonslaught.fsnet.co.uk/nonc_.gif

(Message edited by woody on September 09, 2007)

[craig_colliass]

Many thanks Woody I will give them a call tomorrow

[leorcc]

Cool. I see potential.

[craig_colliass]

Could i use the Gimson robotics relay to opperate these relays if so would you recomend the 1 amp or the 10 amp relay and how would i connect them to the 2 x SW61 on a common bracket.thanks

[woody]

Youd need TWO switches / relays ( one for each solenoid ) if you require FWD / STOP /REVERSE.

Your switch choice depends on the solenoid coil wattage .... 24v @1 Amp = 24 watts ....should be OK ....the Albright coil ( SW60 Series ) is rated @ 7 watts.

http://curtisinst.com/index.cfm?fuseaction=cProducts.DownloadPDF&file=50 128RevBhttp://curtisinst.com/index.cfm?fuse...file=50128RevB

http://www.batterypowersystems.co.uk/brochure/5-BatteryPower32-74.pdfhttp://www.batterypowersystems.co.uk...Power32-74.pdf

Dont forget to add snubber / quenching diodes to the solenoid coils!

http://www.bcae1.com/relays.htmhttp://www.bcae1.com/relays.htm

(Message edited by woody on September 09, 2007)

[maddox]

I used an Albright SW88 B 24V to control an overvolted statermotor (then according to the calculation 3.2 kw).

You better can take the B option , as that stands for blow out magnets. This means, the spark created by opening the contacts will be quenched by the magnets.

[leorcc]

I think in this case a duowitch is a better option to activate the solenoids. Then you can activate 1 solenoid on forward push, and one solenoid on reverse.

Technobots has a Electronize multiswitch but I feel that thing is a pretty big for what it must do, Robbe has a RC switch that is a lot smaller and wil do the job as well.

http://at.robbe-online.net/rims_at.storefront/EN/product/1-8445http://at.robbe-online.net/rims_at.s...product/1-8445

This can switch 24V at 5A but Ive also switched Burkerts on 36V with them without any problems. There are 2 pots at the back where you can set the moment of switching, so you can have as much or as litte space between forward and reverse as you want (usually you want as much dead band as possible so no accidental forward reverse switching). There is also a memory funtion, but generally we turn that off (just remove 1 jumper on the board).

1 of the relays connect to 1 block, the other relay to the next.

(Message edited by leorcc on September 10, 2007)