Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

T i m wrote:

Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

It can't be very well regulated if it is dimmable. And it is probably
quite noisy. So it very much depends on how well the item you are
going to use it with can cope with that.



--

Roger Hayter

On 28/12/2017 22:58, T i m wrote:
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Transformer implies non-DC. I see others in the range on a different
website actually say AC.

I would pass and purchase a true 12V DC supply, if that is what you want.

Something like this at £8.77 for 12V @ 10A:

https://www.ebay.co.uk/itm/DC-12V-24...y/181881169501

And cheaper than the Toolsatan offering. Only concern is the output
earthing arrangement. I might be wary to treat the output to be SELV
without knowing more about the unit.

Of course there are others.

I think we would need to know more about the load you want to power with
such a device before being committal one way or the other. Lights are one
thing, sensitive electronics and chargers are quite another thing.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"T i m" wrote in message
...
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?


It can't be very well regulated if it is dimmable.

Yes, that got me wondering and hence why I asked here.

And it is probably
quite noisy.

Ok.

So it very much depends on how well the item you are
going to use it with can cope with that.

Good point. It was just that the world is still 'weird' because of
that Xmyth thing and Toolstation are just down the road, *if* it was
just a std 12V SMPSU etc.

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

Cheers, T i m

T i m wrote:
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

Be aware that these lighting type transformers rarely produce DC and
have a minimum load usually of around half the max output before they
will switch on. The output voltage quoted is often the RMS value of a
non sinusoid. So ideal for lighting but not a lot else. I have used them
for anti rust heating with resistive loads in the past.

On Fri, 29 Dec 2017 00:32:16 +0000, Fredxx wrote:

On 28/12/2017 22:58, T i m wrote:
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Transformer implies non-DC. I see others in the range on a different
website actually say AC.

Good point. I initially thought they were for LEDs but later saw they
weren't. I have used one to replace similar in a floor standing lamp
with a halogen light and that of course wouldn't need to be polarised

I would pass and purchase a true 12V DC supply, if that is what you want.

Something like this at £8.77 for 12V @ 10A:

https://www.ebay.co.uk/itm/DC-12V-24...y/181881169501

Yes, I went to them from a std 'laptop' type PSU but it would need
casing up ... or fitting inside the PC PSU case than currently only
holds a 120mm fan.

And cheaper than the Toolsatan offering. Only concern is the output
earthing arrangement. I might be wary to treat the output to be SELV
without knowing more about the unit.

It was just something I could go and get locally today. ;-)

Of course there are others.

As I mentioned elsewhere, I think I might first cut the output lead
off the dead laptop style PSU and connect it up to my bench PSU and
remind myself what current it (my home server) actually draws (worst
case) and go from there.

Cheers, T i m

On Fri, 29 Dec 2017 07:54:43 -0000, "Brian Gaff"
wrote:

I think we would need to know more about the load you want to power with
such a device before being committal one way or the other. Lights are one
thing, sensitive electronics and chargers are quite another thing.

Quite. My question was really 'are these Electronic transformers'
really just std SMPSU's but marketed as Electronic Transformers to
cater for electricians who may not know what a SMPSU was?

I think the answers so far suggest they are probably not straight
SMPSU's, as in a laptop PSU and so I'll look elsewhere.

Cheers, T i m

T i m wrote:

On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?


It can't be very well regulated if it is dimmable.

Yes, that got me wondering and hence why I asked here.

And it is probably
quite noisy.

Ok.

So it very much depends on how well the item you are
going to use it with can cope with that.

Good point. It was just that the world is still 'weird' because of
that Xmyth thing and Toolstation are just down the road, *if* it was
just a std 12V SMPSU etc.

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

Cheers, T i m

You have probably noticed that the purpose-made ones from the computer
power supply companies are inordinately expensive. Some of these Atom
boards will alternatively take a standard ATX PSU. Otherwise, for
economy, I agree with your plan. But get a good quality one as it is a
SPOF for your server, even if you have a UPS.

--

Roger Hayter

T i m wrote:
On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?


It can't be very well regulated if it is dimmable.

Yes, that got me wondering and hence why I asked here.

And it is probably
quite noisy.

Ok.

So it very much depends on how well the item you are
going to use it with can cope with that.

Good point. It was just that the world is still 'weird' because of
that Xmyth thing and Toolstation are just down the road, *if* it was
just a std 12V SMPSU etc.

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

I doubt very much if you need anything like 7 amps.

--
Chris Green
·

Chris Green wrote:

T i m wrote:
On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...formers/sd3306
/Elec tronic+Transformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?


It can't be very well regulated if it is dimmable.

Yes, that got me wondering and hence why I asked here.

And it is probably
quite noisy.

Ok.

So it very much depends on how well the item you are
going to use it with can cope with that.

Good point. It was just that the world is still 'weird' because of
that Xmyth thing and Toolstation are just down the road, *if* it was
just a std 12V SMPSU etc.

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

I doubt very much if you need anything like 7 amps.

A significant component is the starting current for the drives. If
this is not specified then you really need an oscilloscope to check.
Even laptop drives may draw twice their rated current when operating.

--

Roger Hayter

T i m wrote:

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

Distress purchase if you need one before the world gets back to normal,
and can measure that 5A would suffice?

http://maplin.co.uk/p/psu-n63jn

On Fri, 29 Dec 2017 10:04:44 +0000, Bob Minchin
wrote:

T i m wrote:
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

Be aware that these lighting type transformers rarely produce DC and
have a minimum load usually of around half the max output before they
will switch on. The output voltage quoted is often the RMS value of a
non sinusoid. So ideal for lighting but not a lot else. I have used them
for anti rust heating with resistive loads in the past.


Thanks for the heads up Bob. From the feedback here I think I was just
wishful thinking, especially with the lack of any real data presented
on the Toolstation website on the things.

Back to a 'proper' SMPSU of some sort. ;-)

Cheers, T i m

Roger Hayter wrote:
If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

I doubt very much if you need anything like 7 amps.

A significant component is the starting current for the drives. If
this is not specified then you really need an oscilloscope to check.
Even laptop drives may draw twice their rated current when operating.

So stagger the startup. Most PSUs will handle short term surges more
than their rated output anyway and/or the output will droop a bit as
the drives spin up.

--
Chris Green
·

On Friday, 29 December 2017 10:03:32 UTC, T i m wrote:
On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

a lighting psu is totally utterly & completely unfit for that purpose


NT

Chris Green wrote:

Roger Hayter wrote:
If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

I doubt very much if you need anything like 7 amps.

A significant component is the starting current for the drives. If
this is not specified then you really need an oscilloscope to check.
Even laptop drives may draw twice their rated current when operating.

So stagger the startup. Most PSUs will handle short term surges more
than their rated output anyway and/or the output will droop a bit as
the drives spin up.

If the output droops the CPU may reset or generate unrecoverable errors
causing a reboot. Although the drives may stay running and therefore
the process not be infinitely repeated, this is a bad idea which could
cause data corruption or electronic harm of some sort e.g. to voltage
regulators.

Staggering the drive start up is easier said then done unless the
hardware is designed to do this.

--

Roger Hayter

On Fri, 29 Dec 2017 11:05:27 +0000, (Roger Hayter)
wrote:

snip

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.


You have probably noticed that the purpose-made ones from the computer
power supply companies are inordinately expensive.

I have indeed. ;-(

Some of these Atom
boards will alternatively take a standard ATX PSU.

Yes, this one was powered by such when I first built it but took it to
the Pico ATX PSU when the conventional PSU fan got noisy (and a 400W
PSU (needed to get a quiet / 120mm fan) was a bit of an overkill).

I think the Pico supply is 160W and I think it suggested a 15A (12V)
PSU (if fully loaded etc).

Otherwise, for
economy, I agree with your plan. But get a good quality one as it is a
SPOF for your server, even if you have a UPS.

Agreed ... that's why I was always a bit cautious about this 'cheap'
PSU my mate gave me.

Cheers, T i m

On Fri, 29 Dec 2017 11:07:59 +0000, Chris Green wrote:

snip

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

Agreed ... and why I gave the 7A PSU a go, assuming it was only really
good for 5 etc.

I doubt very much if you need anything like 7 amps.

You may well be right and I think I'd be happy with a *quality* 5A PSU
(or a cheaper 10A etc). ;-)

But, 'you can manage what you can measure' so I'll try it on my bench
PSU first and 1) make sure everything is ok (Bench PSU is current
limitable and goes up to 15A) and see what it actually draws on
startup.

Cheers, T i m

On Fri, 29 Dec 2017 11:21:49 +0000, (Roger Hayter)
wrote:

snip

A significant component is the starting current for the drives.

I remember my old NW 3.12 server and it had 5 SCSI drives and hearing
them all spin up on boot. ;-)

If
this is not specified then you really need an oscilloscope to check.
Even laptop drives may draw twice their rated current when operating.

These (x3) are Hitachi 500G SATA drives from about 5 years ago FWIW.

I think it's a Dual core Atom, no optical drive, 4G RAM in 2x2 and the
Pico PSU just powers the mobo, drives and the 12V 120mm low power /
slow fan in the std ATX PSU case.

I fitted the DC jack socket to the case just under the PSU (Mini tower
case standing behind the lounge TV). The Topfield is normally
connected to the server but doesn't add any extra load, as is a 3TB
powered external backup drive.

Cheers, T i m

p.s. I've bought some Arctic F12 Silent fans and may swap the one out
of the server to see if it could be quieter still (you can only hear
that it's on after you turn it off). ;-)

The 3 x laptop drives are suspended from silicon bands. ;-)

On Fri, 29 Dec 2017 11:35:12 +0000, Andy Burns
wrote:

T i m wrote:

A mate gave me the 12V 7A laptop type PSU a good while back but I
doubt it is a good one or able to maintain 7A. I might rig up a feed
using my variable bench PSU and see what it actually draws worst-case
and get something that can cope with that easily.

Distress purchase

Hehe ..

if you need one before the world gets back to normal,

;-)

and can measure that 5A would suffice?

http://maplin.co.uk/p/psu-n63jn

Thanks for that Andy ... and could be a solution (even at that 'sea'
price) if it's likely to be a 'good' / quality item?

It's like when you buy these replacement laptop PSUs and they weigh a
fraction of the original. ;-(

Cheers, T i m

On Fri, 29 Dec 2017 15:05:37 +0000, (Roger Hayter)
wrote:

snip

If the output droops the CPU may reset or generate unrecoverable errors
causing a reboot. Although the drives may stay running and therefore
the process not be infinitely repeated, this is a bad idea which could
cause data corruption or electronic harm of some sort e.g. to voltage
regulators.

Noted.

Staggering the drive start up is easier said then done unless the
hardware is designed to do this.

I think I may have seen a 'Spinup delay' on some Mobos (for std drives
even) but I'm not sure if it is present on this one (and as it's
offline I can't check either).

As I've not touched the server for ages I might pull it out in any
case and put it on the bench and 1) check it over, 2) measure the
current, 3) replace the fan in the PSU for one of these Arctic F12
'Silents' and 4) blow it out.

Technically, I should have retired it a while back when I built the
WHS 2011 but whilst this old WHS V1 keeps going ... ;-)

Cheers, T i m

On Fri, 29 Dec 2017 05:54:38 -0800 (PST), wrote:

On Friday, 29 December 2017 10:03:32 UTC, T i m wrote:
On Thu, 28 Dec 2017 23:11:35 +0000, (Roger Hayter)
wrote:

snip

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...rs/sd3306/Elec
tronic+Transformer/p11098

It's to power my home server that uses a fanless Atom board, 3 x 500G
laptop drives and one of those low power PSU's that take a single
input voltage and fit in the mobo power connector.

a lighting psu is totally utterly & completely unfit for that purpose

Agreed.

Cheers, T i m

Roger Hayter wrote:
Chris Green wrote:

Roger Hayter wrote:
If I get one of those semi open frame type SMPSU's I could put it
inside the PSU case as that only contains the one 120mm fan atm.

That's a *lot* of power for a fanless Atom based board. My full-blown
desktop machine with a (6th gen, or maybe even 5th gen) I5 and three
disk drives only consumes 18 watts when idle and maybe 25/30 watts
when working hard. That's a maximum of around 3 amps at 12 volts.

I doubt very much if you need anything like 7 amps.

A significant component is the starting current for the drives. If
this is not specified then you really need an oscilloscope to check.
Even laptop drives may draw twice their rated current when operating.

So stagger the startup. Most PSUs will handle short term surges more
than their rated output anyway and/or the output will droop a bit as
the drives spin up.

If the output droops the CPU may reset or generate unrecoverable errors
causing a reboot. Although the drives may stay running and therefore
the process not be infinitely repeated, this is a bad idea which could
cause data corruption or electronic harm of some sort e.g. to voltage
regulators.

Possibly, but not very likely as it's a 12 volt supply and the CPU
etc. probably all run at 3.3 volts, that leaves *lots* of headroom for
the 12 volts to dip a little without having any effect at all on the
electronics.


Staggering the drive start up is easier said then done unless the
hardware is designed to do this.

True, it was only a possible idea.

I *still* think 12 volts 7 amps sounds a crazy amount of power for a
fanless Atom board (even including some disk drives). It's something
like three times as much power as my I5 desktop with four disk drives
in takes.

--
Chris Green
·

On Fri, 29 Dec 2017 17:00:07 +0000, Chris Green wrote:

snip

I *still* think 12 volts 7 amps sounds a crazy amount of power for a
fanless Atom board (even including some disk drives).

I've not suggested anything otherwise, just that my friend had a 7A
PSU spare and I thought bigger might be better (considering it was
made in the Far East, was 'cheap', felt 'light' and I wanted it to run
cool rather than hot)?

It's something
like three times as much power as my I5 desktop with four disk drives
in takes.

And I wonder what capacity PSU you have in there? 450-500W possibly?
;-)

Cheers, T i m

T i m wrote:
On Fri, 29 Dec 2017 17:00:07 +0000, Chris Green wrote:

snip

I *still* think 12 volts 7 amps sounds a crazy amount of power for a
fanless Atom board (even including some disk drives).

I've not suggested anything otherwise, just that my friend had a 7A
PSU spare and I thought bigger might be better (considering it was
made in the Far East, was 'cheap', felt 'light' and I wanted it to run
cool rather than hot)?

It's something
like three times as much power as my I5 desktop with four disk drives
in takes.

And I wonder what capacity PSU you have in there? 450-500W possibly?
;-)

It has an 80 watt power supply. :-) For the good reason that a
larger power supply would probably be horribly inefficient when
running at 18 watts.

--
Chris Green
·

On Fri, 29 Dec 2017 21:12:55 +0000, Chris Green wrote:

T i m wrote:
On Fri, 29 Dec 2017 17:00:07 +0000, Chris Green wrote:

snip

I *still* think 12 volts 7 amps sounds a crazy amount of power for a
fanless Atom board (even including some disk drives).

I've not suggested anything otherwise, just that my friend had a 7A
PSU spare and I thought bigger might be better (considering it was
made in the Far East, was 'cheap', felt 'light' and I wanted it to run
cool rather than hot)?

It's something
like three times as much power as my I5 desktop with four disk drives
in takes.

And I wonder what capacity PSU you have in there? 450-500W possibly?
;-)

It has an 80 watt power supply. :-)

Ah, ok. ;-)

For the good reason that a
larger power supply would probably be horribly inefficient when
running at 18 watts.

Quite ('80 Plus' etc).

As I have said elsewhere, I think I'd be happy with a 'good' 5A PSU,
allowing for a little overhead and happy if it wasn't running close to
maximum design load just to get maximum efficiency etc.

But I still intend to measure it as if it really only draws what we
think it might, I could get away with something even smaller (cheaper
and easier to get). ;-)

Cheers, T i m

T i m wrote:
On Fri, 29 Dec 2017 10:04:44 +0000, Bob Minchin
wrote:

T i m wrote:
Hi all,

I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Cheers, T i m

Be aware that these lighting type transformers rarely produce DC and
have a minimum load usually of around half the max output before they
will switch on. The output voltage quoted is often the RMS value of a
non sinusoid. So ideal for lighting but not a lot else. I have used them
for anti rust heating with resistive loads in the past.


Thanks for the heads up Bob. From the feedback here I think I was just
wishful thinking, especially with the lack of any real data presented
on the Toolstation website on the things.

Back to a 'proper' SMPSU of some sort. ;-)

Cheers, T i m

Tim Try this type

http://tinyurl.com/yad37u9v

https://www.ebay.co.uk/itm/DC-12V-LE...zaBQZFSKMFnD2g

There are lots of vendors on ebay and they possibly all come out of the
same factory. I've used a number for various electronic applications.
The regulation is good and the output voltage is trimmable by a few %
either way and there is no minimum load.

Bob

On Fri, 29 Dec 2017 22:18:31 +0000, Bob Minchin
wrote:

snip

Back to a 'proper' SMPSU of some sort. ;-)

Cheers, T i m

Tim Try this type

http://tinyurl.com/yad37u9v

https://www.ebay.co.uk/itm/DC-12V-LE...zaBQZFSKMFnD2g

Thanks for that Bob.

I actually have that type of PSU (12V 20A or so) in my 3D printer but
it came as part of a kit (so I didn't spec it as such).

There are lots of vendors on ebay and they possibly all come out of the
same factory.

Quite possibly. A mate had some specialised garage kit that had a
similar PSU in it that was knocked out during a lightening strike. I
found him an exact replacement online that was about 45 quid including
next day delivery ... the suppliers of the garage equipment wanted 200
for the same thing. ;-(

I've used a number for various electronic applications.

Good to know. Oh, I did help wire a couple more up used as CCTV power
supplies. ;-)

The regulation is good and the output voltage is trimmable by a few %
either way and there is no minimum load.

OOI, what sort of overhead (if any) would you set on the capacity of
such a solution?

Say I measure 3A peak on boot and 2A when running but idle, would a 5A
model be overkill?

Cheers, T i m

In article ,
T i m wrote:
I need to replace a laptop style (12V 7A) PSU (not for a laptop) and
was wondering if the sort of thing you can get to power 12V LED lights
would be suitable?

I'm talking of this sort of thing:

https://www.toolstation.com/shop/Lig...sformer/p11098

Is it just a 12V SMPSU or is it summat 'different'?

I find it weird that they don't mention the output voltage in the
blurb, just a range of wattages (it does say 11.4V on the item itself
though).

Something designed for lighting may well not be suitable for other
electronics. Things like how well regulated and smoothed the output is.

Have you looked on Ebay for a generic PS designed to do the job you want?
Can't see it being that much more expensive than a lighting PS.

--
*If love is blind, why is lingerie so popular? *

Dave Plowman London SW
To e-mail, change noise into sound.

On 29/12/2017 23:40, T i m wrote:
On Fri, 29 Dec 2017 22:18:31 +0000, Bob Minchin
wrote:

snip

Back to a 'proper' SMPSU of some sort. ;-)

Cheers, T i m

Tim Try this type

http://tinyurl.com/yad37u9v

https://www.ebay.co.uk/itm/DC-12V-LE...zaBQZFSKMFnD2g

Thanks for that Bob.

I actually have that type of PSU (12V 20A or so) in my 3D printer but
it came as part of a kit (so I didn't spec it as such).

There are lots of vendors on ebay and they possibly all come out of the
same factory.

Quite possibly. A mate had some specialised garage kit that had a
similar PSU in it that was knocked out during a lightening strike. I
found him an exact replacement online that was about 45 quid including
next day delivery ... the suppliers of the garage equipment wanted 200
for the same thing. ;-(

I've used a number for various electronic applications.

Good to know. Oh, I did help wire a couple more up used as CCTV power
supplies. ;-)

The regulation is good and the output voltage is trimmable by a few %
either way and there is no minimum load.

OOI, what sort of overhead (if any) would you set on the capacity of
such a solution?

Say I measure 3A peak on boot and 2A when running but idle, would a 5A
model be overkill?

Cheers, T i m


http://www.easyflip.co.uk/CPC_Digita...gue/?page=1732

On Sat, 30 Dec 2017 00:22:48 +0000 (GMT), "Dave Plowman (News)"
wrote:

snip

Have you looked on Ebay for a generic PS designed to do the job you want?
Can't see it being that much more expensive than a lighting PS.

It wasn't really the cost but the 'I'd like it now' that was the issue
at the time Dave (this being the 'silly season' and Companies and
postage being all over the place etc). ;-)

So it was a 'what could I go out and buy today that would work
properly ... and if I can't find anything easily at the right price,
I'll get the right thing online when the seasonal dust settles'. ;-)

That said, I ordered the replacement handle for the TD on the 28th and
it arrived on the 29th so it couldn't have been any faster! ;-)

Cheers, T i m

On Sat, 30 Dec 2017 11:26:37 +0000, "dennis@home"
wrote:

snip

OOI, what sort of overhead (if any) would you set on the capacity of
such a solution?

Say I measure 3A peak on boot and 2A when running but idle, would a 5A
model be overkill?

Cheers, T i m


http://www.easyflip.co.uk/CPC_Digita...gue/?page=1732

I don't go straight to CPC (even though I get more catalogues though
the post than I can read) so thanks for that. The only thing is I
don't know what sort of quality the gear is they sell (if / how they
vet stuff) ... if it's just the same stuff found on eBay etc?

Cheers, T i m

On 30/12/2017 12:09, T i m wrote:
On Sat, 30 Dec 2017 11:26:37 +0000, "dennis@home"
wrote:

snip

OOI, what sort of overhead (if any) would you set on the capacity of
such a solution?

Say I measure 3A peak on boot and 2A when running but idle, would a 5A
model be overkill?

Cheers, T i m


http://www.easyflip.co.uk/CPC_Digita...gue/?page=1732

I don't go straight to CPC (even though I get more catalogues though
the post than I can read) so thanks for that. The only thing is I
don't know what sort of quality the gear is they sell (if / how they
vet stuff) ... if it's just the same stuff found on eBay etc?

Cheers, T i m


If they sell rubbish then they will still be there when the courts get
to them, while an ebay seller may well just disappear.

They also tend to be cheaper than amazon for most stuff and the really
cheap stuff is usually shipped from "china" on amazon and ebay.

T i m wrote:

I don't go straight to CPC (even though I get more catalogues though
the post than I can read)

They do seem to overdo it with the catalogues; never a week without one,
and often two ...

T i m wrote:

this being the 'silly season' and Companies and postage being all
over the place etc
Element for my oven ordered Friday am, delivered Saturday am, three
other items ordered since boxing day all delivered, can't grumble.

On Sat, 30 Dec 2017 12:20:37 +0000, "dennis@home"
wrote:

snip

http://www.easyflip.co.uk/CPC_Digita...gue/?page=1732

I don't go straight to CPC (even though I get more catalogues though
the post than I can read) so thanks for that. The only thing is I
don't know what sort of quality the gear is they sell (if / how they
vet stuff) ... if it's just the same stuff found on eBay etc?

Cheers, T i m


If they sell rubbish then they will still be there when the courts get
to them, while an ebay seller may well just disappear.

Good point.

They also tend to be cheaper than amazon for most stuff and the really
cheap stuff is usually shipped from "china" on amazon and ebay.


Noted. I might give em another go then, when I know more accurately
what I want.

Cheers, T i m

On Sat, 30 Dec 2017 12:24:56 +0000, Andy Burns
wrote:

T i m wrote:

I don't go straight to CPC (even though I get more catalogues though
the post than I can read)

They do seem to overdo it with the catalogues; never a week without one,
and often two ...

And if you mix them with Machine Mart, Coopers, Screwfix, Toolstation
and my subscription mags (Kitcar / Motorcycle), there is generally
plenty to browse whilst having a quiet sit down and paper to work on
when cleaning stuff etc. ;-)

Cheers, T i m

On Sat, 30 Dec 2017 12:28:35 +0000, Andy Burns
wrote:

T i m wrote:

this being the 'silly season' and Companies and postage being all
over the place etc
Element for my oven ordered Friday am, delivered Saturday am, three
other items ordered since boxing day all delivered, can't grumble.

I think it can depend on your local PO staff and may also be a weird
side effect of the seasonal chaos where they are pushing stuff though
as fast as possible? The TD handle was on second class and 'due'
between the 1st and 4th of Jan, the sort of delivery time I would
expect to be about right under normal circumstances. shrug

Cheers, T i m

In article ,
T i m wrote:
On Sat, 30 Dec 2017 12:28:35 +0000, Andy Burns
wrote:

T i m wrote:

this being the 'silly season' and Companies and postage being all
over the place etc
Element for my oven ordered Friday am, delivered Saturday am, three
other items ordered since boxing day all delivered, can't grumble.

I think it can depend on your local PO staff and may also be a weird
side effect of the seasonal chaos where they are pushing stuff though
as fast as possible? The TD handle was on second class and 'due'
between the 1st and 4th of Jan, the sort of delivery time I would
expect to be about right under normal circumstances. shrug

I've noticed even second class post can be faster at this time of the
year. Extra staff (or longer hours)?

--
*Go the extra mile. It makes your boss look like an incompetent slacker *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 30 Dec 2017 12:20:37 +0000, dennis@home wrote:

I don't go straight to CPC (even though I get more catalogues though
the post than I can read) so thanks for that. The only thing is I don't
know what sort of quality the gear is they sell (if / how they vet
stuff) ... if it's just the same stuff found on eBay etc?

If they sell rubbish then they will still be there when the courts get
to them, while an ebay seller may well just disappear.

I did buy a couple of small USB PSUs for some Raspberry Pis a couple of
years ago. They contacted me soon after to tell me they wer now subject
to recall, and sent me replacements.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor