Mains power supply for 12v dc motor

[Michael GilliganParticipant @michaelgilligan61133]

When making my original suggestion, I assumed [based on its declared purpose] that the motor would only be used intermittently. In which case, I was thinking of a battery somthing like this: **LINK**

https://docs-emea.rs-online.com/webdocs/16c3/0900766b816c34e3.pdf

… Which can be kept on permanent trickle charge.

Is that unrealistic ?

MichaelG.

[Frances IoMParticipant @francesiom58905]

SOD – yes the cost of a 120+VA transformer is way more than the cost of a single IC and a few components using a switched mode technique – these usually auto sense a 6V or 12V battery + depth of discharge – I suspect the 24V are similar. Gone are the days of a heavy transformer and the selenium rectifiers that indicated failure by odour.

Re ATX PSU’s most do have a 5v minimum load requirement – the 80A server type are adjustable between 12.1 and typ 12.5V to allow for cable loss enroute to the compter board – on which is generally a smaller switch mode supply for the 3.3V – tho the one I illustrated will supply an 8A 3.3V standby supply for keeping some circuitry alive – it would be useful if two could be placed in serial to provide 24V but on all I’ve seen the bonding back to the case + earth makes this tricky (doable but needs a very awkward chassis isolation of one PSU)

[Brian Fisher 1Participant @brianfisher1]

Hi.

Thanks for all your responses to date. I have not been ignoring you all but have been inwardly digesting all the comments. I am learning a lot from it all.

One thought which has come to mind is that if a 20amp led power supply objected to the high inrush current of a motor would it improve things if a variable resistance was wired in series with the motor to give it a soft start. So long as I always remember to use max resistance at start-up.

Or alternatively one of Geoff's suggested speed control devices.

Cheers. Brian

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