relay

Hi,
Could I use this relay along with a Robochalange Battle Switch to control a Speed 900 Motor to power a spinning drum?
http://www.halfords.com/webapp/wcs/stor ... e=shopping

In general automotive relays aren't upto the job of switching inductive loads like motors.

Quote:

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Applications Considerations
In some applications, the contacts may be subjected to punishing current
surges which can drastically reduce their life. Consider an incandescent
lamp. A 40 watt, 120V AC lamp has a current rating of .33 ampere. The
resistance of the filament when cold, however, is so low that initial inrush
current may be as much as 6 amps! To attempt to switch the 40 watt
lamp with, say 2 amp contacts will result in early contact failure.
The same situation exists in motor and transformer applications, and in
applications where significant distributed line capacitance exists. During
start-up, a motor can pull 600% or more of its running current. Thus, a 3
amp motor may actually pull 18 amps or more during start-up. A contact
rated at least 20 amps should be used. Additionally, when disconnected,
a motor acts as a voltage generator as it slows to a stop. Depending on
the motor, it can feed back into the circuit voltages well in excess of
rated line voltage. These voltages appearing across the separating
contacts can cause a destructive arc to exist between the contacts, which
can lead to early failure of the contacts. Because of this, it is desirable to
suppress the arc.

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A bigger one like this may do the job

http://cgi.ebay.co.uk/Automotive-Relay- ... 1e63f40f67

but i would always recommend the solid state relays for reliability. I can't vouch the same for these as I have never used them.