12v DC supply for mini computer

[Mr Chrysalis]

I have a mini computer to use in the Motorhome. I use it for watching SkyGo on the TV. It is powered by 12v D.C. from a 240v AC adaptor.

I want to be able to use it off grid so obviously I can plug it into my PSW inverter but it is not very efficient to conver from 14v D.C. to 240v ac then back to 12v D.C.

Is there a device I can get that will give me stable 12v D.C. from a car socket ( which usually gives 13-15v approx)? I think it might be called a buck converter?

I have seen in car laptop adaptors which claim to give a variety of outputs but they don’t seem to have switched do not confident how you know what output they give

 

[RubyOptics]

Are you using the Pico style PSU?

 

[cmcardle75]

I have a mini computer to use in the Motorhome. I use it for watching SkyGo on the TV. It is powered by 12v D.C. from a 240v AC adaptor.

I want to be able to use it off grid so obviously I can plug it into my PSW inverter but it is not very efficient to conver from 14v D.C. to 240v ac then back to 12v D.C.

Is there a device I can get that will give me stable 12v D.C. from a car socket ( which usually gives 13-15v approx)? I think it might be called a buck converter?

I have seen in car laptop adaptors which claim to give a variety of outputs but they don’t seem to have switched do not confident how you know what output they give

There are plenty available. However, you need to know the required ampage and plug size to get the right one. You can get universal ones, but they are more expensive and the tips are easily lost.

 

[autorouter]

I think it might be called a buck converter?

A buck converter only reduces voltage, doesn't increase it. For example a USB adaptor, 12V to 5V.
A boost converter only increases voltage, doesn't decrease it. For example, a laptop adaptor, 12V to 19V.
A buck-boost converter gives the specified output voltage, whether the input is higher or lower. So a car adaptor that gives 12.0V from an input of 10 to 15V is a buck-boost converter.

Having said all that, a buck converter you might think will probably be OK, because you won't want to watch TV if your battery is down to 12.0V. However the converter requires some 'headroom', of at least 0.6V, so it will cut out as the voltage falls to 12.6V - not what you want. So you want a buck-boost converter. Unfortunately some adaptors are buck type, and the ad doesn't make it clear. So be careful.

 

[pappajohn]

However the converter requires some 'headroom', of at least 0.6V, so it will cut out as the voltage falls to 12.6V

Not much use then as a full charged battery has a resting voltage of 12.6v

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[cmcardle75]

The descriptions won't mention "buck" or "boost", so these won't be good search terms in eBay. You're looking for something like the following, but check the plug size, the max amps and the delivery times to make sure it isn't coming on the next clipper ship to be held hostage in a warehouse for 35p import duty and a £30 "convenience" fee.

https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=143325591694

It claims 12-24V, not 12.6V - 24V. My guess it that it will work down to 11V, but it doesn't claim this and I haven't got one to test! OTOH, it is only 7 quid, so cheap enough to give a try.

 

[Richard n Ann]

Because you're only dropping couple of volts you could use a linear regulator like the LM7812.

78xx - Wikipedia

en.m.wikipedia.org

 

[cmcardle75]

Because you're only dropping couple of volts you could use a linear regulator like the LM7812.

78xx - Wikipedia

en.m.wikipedia.org

Unfortunately, a 7812 based device won't work in this scenario.
(1) You would need to build this into something usable, it is just a component
(2) It will be very inefficient (and thus will probably run very hot).
(3) Limited continuous current capability
(4) Does not work when you don't need to drop any volts. A 7812 circuit will typically have a minimum 15V input.

 

[Mark and Mindy]

I am impressed. Mini computer in Van?

I started my career on a Digital Equipment DEC PDP-11 Minicomputer. It was tiny compared to a Mainframe

Mark

 

[cmcardle75]

I am impressed. Mini computer in Van?

I started my career on a Digital Equipment DEC PDP-11 Minicomputer. It was tiny compared to a Mainframe

View attachment 435181

Mark

A PDP-11 was our first home computer.

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[Gromett]

I have a mini computer to use in the Motorhome. I use it for watching SkyGo on the TV. It is powered by 12v D.C. from a 240v AC adaptor.

I want to be able to use it off grid so obviously I can plug it into my PSW inverter but it is not very efficient to conver from 14v D.C. to 240v ac then back to 12v D.C.

Is there a device I can get that will give me stable 12v D.C. from a car socket ( which usually gives 13-15v approx)? I think it might be called a buck converter?

I have seen in car laptop adaptors which claim to give a variety of outputs but they don’t seem to have switched do not confident how you know what output they give

Just search for "12v regulator" on Amazon or Ebay.

This is similar to the one I used.

DC 8V~40V to 12V Auto Step Up/Down Voltage Converter 6A 72W Adjustable Boost Buck Voltage Regulator Module Transformer Module for Power Conversion : Amazon.co.uk: Automotive

DC 8V~40V to 12V Auto Step Up/Down Voltage Converter 6A 72W Adjustable Boost Buck Voltage Regulator Module Transformer Module for Power Conversion : Amazon.co.uk: Automotive

amzn.to

 

[autorouter]

This is the kind of thing you want. It's in a box with buttons to press. You can get the inside working circuit board without the box and buttons if you are integrating it into a device like a media server.
Amazon product ASIN B07ZQXXVCN

 

[Mr Chrysalis]

Are you using the Pico style PSU?

Thankyou. Sorry I don’t know what that is. The mini pc came with a 240v to 12v D.C. adaptor, looks like a laptop one

 

[Mr Chrysalis]

There are plenty available. However, you need to know the required ampage and plug size to get the right one. You can get universal ones, but they are more expensive and the tips are easily lost.

Thankyou. The supplies mains adaptor gives 2.5A 30W

 

[Mr Chrysalis]

A buck converter only reduces voltage, doesn't increase it. For example a USB adaptor, 12V to 5V.
A boost converter only increases voltage, doesn't decrease it. For example, a laptop adaptor, 12V to 19V.
A buck-boost converter gives the specified output voltage, whether the input is higher or lower. So a car adaptor that gives 12.0V from an input of 10 to 15V is a buck-boost converter.

Having said all that, a buck converter you might think will probably be OK, because you won't want to watch TV if your battery is down to 12.0V. However the converter requires some 'headroom', of at least 0.6V, so it will cut out as the voltage falls to 12.6V - not what you want. So you want a buck-boost converter. Unfortunately some adaptors are buck type, and the ad doesn't make it clear. So be careful.

Thankyou. This is the adaptor, and the mini PC. The adaptor converts 240v AC to 12v D.C. 2.5a 30W. I want the same output with a 12-15v dc input so sounds like a buck boost converter?

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[Mr Chrysalis]

The descriptions won't mention "buck" or "boost", so these won't be good search terms in eBay. You're looking for something like the following, but check the plug size, the max amps and the delivery times to make sure it isn't coming on the next clipper ship to be held hostage in a warehouse for 35p import duty and a £30 "convenience" fee.

https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=143325591694

It claims 12-24V, not 12.6V - 24V. My guess it that it will work down to 11V, but it doesn't claim this and I haven't got one to test! OTOH, it is only 7 quid, so cheap enough to give a try.

Thankyou. That’s close to what I need, but I guess 2A is not quite enough - I didn’t say this before but it needs 2.5A

 

[Mr Chrysalis]

Because you're only dropping couple of volts you could use a linear regulator like the LM7812.

78xx - Wikipedia

en.m.wikipedia.org

Thanks but a bit too techy for me I think!

 

[kevenh]

What's your load like?
I use this for a telescope's motorised GoTo base: <Broken link removed>

edit: >2A? OK, they have larger battery packs available

 

[Mr Chrysalis]

I am impressed. Mini computer in Van?

I started my career on a Digital Equipment DEC PDP-11 Minicomputer. It was tiny compared to a Mainframe

View attachment 435181

Mark

It is just to watch SkyGo on the van TV. You cannot cast Skygo from an iPad, my MacBook is too old to run The newer OS that is needed for Skygo and my Windows laptop is too old for Windows 10 which Skygo needs. I had decided to buy a new laptop, but as I didn’t need a screen or keyboard I have a mini keyboard with trackpad) it was a lot of expense.
This ACEPC Mini PC is 8GB Ram, 256GB SSD ROM, spare socket for another TB SDD if wanted and is loaded with Windows 10 Pro. Normal Amazon price £225. I got it on a lightening deal for £158. I’ve loaded Sky Go VLC Player and BBC iPlayer. It can run 2 HD TVs and separate speaker if required, and has 2 USB 3 and 2 USB2 sockets so I can plug in an external HDD to play avi films or mo4 music. Perfect for what I want other than a preference to run without using my Inverter if off grid. It gets its signal from my Mifi which has a Sky SIM so unlimited data when using SkyGo. I could also load Amazon and Netflix but already have those on a Firestick

 

[Mr Chrysalis]

Just search for "12v regulator" on Amazon or Ebay.

This is similar to the one I used.

DC 8V~40V to 12V Auto Step Up/Down Voltage Converter 6A 72W Adjustable Boost Buck Voltage Regulator Module Transformer Module for Power Conversion : Amazon.co.uk: Automotive

DC 8V~40V to 12V Auto Step Up/Down Voltage Converter 6A 72W Adjustable Boost Buck Voltage Regulator Module Transformer Module for Power Conversion : Amazon.co.uk: Automotive

amzn.to

Thant you. That looks perfect.

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[Mr Chrysalis]

This is the kind of thing you want. It's in a box with buttons to press. You can get the inside working circuit board without the box and buttons if you are integrating it into a device like a media server.
Amazon product ASIN B07ZQXXVCN

Thankyou that looks good but I think I only need the 12v output above

 

[Mr Chrysalis]

Thanks for all your help. Now I know what to search for, I have bought t
https://rover.ebay.com/rover/1/710-...0001&campid=5338547443&icep_item=373183859370

Do you think it will be ok? ( assuming I manage to solder the plugs on! )

 

[Pugsy]

I used power4laptops ,for my 2 laptops

The Web's Largest Supplier Of Laptop Power Adapters & Laptop Chargers | Power4Laptops

The Web's Largest Supplier Of Laptop Power Adapters & Laptop Chargers. Over 200,000 models in stock.

www.power4laptops.co.uk

Very helpful,they sorted my 12v tv connection also
Cheers Cris.

 

[cmcardle75]

Thankyou. Sorry I don’t know what that is. The mini pc came with a 240v to 12v D.C. adaptor, looks like a laptop one

Do you have a picture of its rating plate? It may well be a decent switch mode already that doesn't need any of this and can run off a dirty 12V already. It'll probably just be converting to 5V and 3.3V inside and use the 12V direct for only a few fans, and may even clean it up for the 12V bus. I assume no spinny hard disks?

 

[Mr Chrysalis]

Do you have a picture of its rating plate? It may well be a decent switch mode already that doesn't need any of this and can run off a dirty 12V already. It'll probably just be converting to 5V and 3.3V inside and use the 12V direct for only a few fans, and may even clean it up for the 12V bus. I assume no spinny hard disks?

Yes it’s here. And no moving parts except the fan. It’s an SSD

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[Mr Chrysalis]

I used power4laptops ,for my 2 laptops

The Web's Largest Supplier Of Laptop Power Adapters & Laptop Chargers | Power4Laptops

The Web's Largest Supplier Of Laptop Power Adapters & Laptop Chargers. Over 200,000 models in stock.

www.power4laptops.co.uk

Very helpful,they sorted my 12v tv connection also
Cheers Cris.

Thankyou

 

[G-RMPS]

I am impressed. Mini computer in Van?

I started my career on a Digital Equipment DEC PDP-11 Minicomputer. It was tiny compared to a Mainframe

View attachment 435181

Mark

I worked for DEC for 17 years! Best company around at the time...

 

[cmcardle75]

Yes it’s here. And no moving parts except the fan. It’s an SSD

Hmmm. Inconclusive. It would probably work direct, but probably not worth the risk. I'd go with the module you bought.

On a different note, I actually used to work in exactly the same building as the manufacturer's address!

 

[Mark and Mindy]

I worked for DEC for 17 years! Best company around at the time...

And to think that Digital were brought and taken over by that upstart Compaq. How did that happen? At least HP did the decent thing and purchased Compaq. I was working for HP at the time and within 1 day of the takeover I got transferred to a Compaq project which was really all Ex Digital.

Years before I had a micro and I didn't really have a real DEC PDP-11 but I did have the PDP-11 BASIC programming manual which I used to learn to code.

 

[kevenh]

The Talentcell idea could work.
Maybe even with my YB1206000 3A o/p rated model
<Broken link removed>
but they have beefier ones.
It works well on my scope - still on the 1st charge after 4 nights viewing and scope moving. Different load to the OP.

They can be on charge while in use.
edit: It comes with a y-split cable to help with in use charging as the In is also the Out

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