chunky 12v transformer

[virgilns]

Wow...great feedback gents. thanks.

I'm looking to do a few things...

using 12volt radiator fans in a spray booth (I have the fans and they are very powerful, so saves getting new fans...) and these take a reasonable current

bench test the injection kit of my TVR with a new ecu...need to fire injectors on the bench and run some sensors etc

and running some motors for a toy car for the little one...

think the battery will be a good way forward...thanks

 

[bernardgreen]

using 12volt radiator fans in a spray booth (I have the fans and they are very powerful, so saves getting new fans...) and these take a reasonable current

CAUTION Paint fumes are inflammable and can be ignited by the sparks created by the brush gear inside DC motors. AC induction motors without brushes are the motor of choice or use a belt drive system to take the DC motor out of the fume ducting.

 

[SimonH2]

The alternator idea is a good one, but I would leave it as 1:1, as at 1000rpm the alternator doesn't really output a great deal, if anything.

Which is why I suggested a step UP drive to give around 9k RPM - about the middle of the speed range for a typical automotive alternator. Direct drive at 3k RPM would work, but is towards the low end and would reduce output somewhat.

You can also leave it closely coupled. If you want to change the ratio, how about a cheap Clark bench drill, modified with an alternator in the chuck.

Not a lot of power in a typical bench drill.

As I (not very successfully it seems) hinted at, if the OP wants a lot of current and to maintain 14V then he'd need quite a hefty power supply for that. It was only an idea anyway.