Power supply units - which type?

The power supply unit for my dew heater appears to have gone bust and I need to get a new one.
What is the difference btweeen Regulated vs Unregulated vs Switched Mode?
IIRC, I specifically got a regulated one a few years back as I understand the unregulated ones are to be avoided - forget why though.
However, what are switched mode? - i have seen some units on ebay saying they are regulated switching units.

Thanks,

Michael.

Nor sure about switched mode but definitely stay with a regulated power source. Unregulated power supplys will vary in voltage as the current draw changes. This could result in a low voltage and high current situation which could cause problems. Maplins do a range of supplies but most are just over 13V.

Switchmodes are for high power systems, its akin to having 2 power supplies where there is an internal switch constantly switching between one and the other. As neither is constantly on, it prevents overheating. PC power supplies are switch mode. I use one of these to run my 12" dew heaters, it gives out big amps and I had one spare lying around.

Johns comments about regulated/unregulated are correct, stay away from unregulated supplies for astro equipment. Cost doesnt come into it.

Hi Michael
I purchased a regulated switching mode power supply in Maplins in Dublin last year; it works my Kendrick dew heater (x2 straps for 8” SCT and 50mm guide scope), the CG5-GT Mount, and a CCD guide camera (12 vdc supply from Kendrick unit). I modified the tip to take a car (cigarette) type connection with correct polarity.

Model: L11BQ,
www.maplin.co.uk/Module.aspx?moduleno=48517

Its probably overkill for what you want it to do but I am sure it could also serve for other power uses.

Best wishes and clear skies
Mike

Thanks lads.

The one I have I ordered from Farnells a couple of few years ago.
I just had a check on it - it is a switching mode multi-voltage power supply.,
For the 12V setting, it is rated for 5A.
Cost me 50-60 euro at the time IIRC. Surprised that it has gone belly-up.

That one looks interesting Mike. Thanks.
Like you, I have the power supply linked up to my Kendrick unit (Digifire).
From this, I have my dew band and the focus controller connected up.

Michael.