blueberrypi1
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Powering PI from 12v DC

Mon Mar 09, 2015 8:21 pm

evening,

I'm looking to power my pi from 12v DC from an intruder alarm panel, can anyone point me in the direction of where to buy a 12v>5v converter?

thanks

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DougieLawson
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 8:24 pm

Your nearest car spares shop will have cigarette lighter to USB adapters. They're 12V to 5V.
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ragnarjensen
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 9:26 pm

I have a bunch of these.
http://www.ebay.com/itm/3Meter-New-DC-1 ... 462a79dc24

They seem to work OK.

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SteveDee
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 9:58 pm


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PeterO
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 10:07 pm

IF you want to make sure you've got enough current capability .... http://skpang.co.uk/catalog/dcdc-conver ... p-537.html
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 10:24 pm

blueberrypi1 wrote:evening,

I'm looking to power my pi from 12v DC from an intruder alarm panel, can anyone point me in the direction of where to buy a 12v>5v converter?

thanks
Remember that the additional load will reduce the intruder alarm run time on battery. If this is an important consideration (for security or insurance reasons), you may need to consult your alarm supplier/maintainer and if necessary upgrade the alarm supply and battery.
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mahjongg
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Re: Powering PI from 12v DC

Mon Mar 09, 2015 10:29 pm

I'm with Dougie, for about $5 you can buy car cigarette lighter USB adapters almost anywhere, street markets, dollar shops etc, even at ALDI.

just unscrew the top and the thing falls apart, and reveals a 12V to 5V switcher at 1A, for almost no money at all. Maybe you even have one in a drawer somewhere. The best part is they have a regular USB output already.

As for the 12V input, the wire that runs to the round tip is the +12V input, and the two side springs are GND.

rahlquist
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 11:01 am

I have a nice 12v 2A supply from a router I am using. Combined with http://www.ebay.com/itm/310813369212?_t ... EBIDX%3AIT

I still see blinking power LED. No matter what I do I cant seem to totally escape it.

klricks
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 2:00 pm

rahlquist wrote:I have a nice 12v 2A supply from a router I am using. Combined with http://www.ebay.com/itm/310813369212?_t ... EBIDX%3AIT

I still see blinking power LED. No matter what I do I cant seem to totally escape it.
I am running with a 5V 10A industrial supply with adjustable trim and still had power problems until I made my own cable with 22ga wire.
Unless specified otherwise my response is based on the latest and fully updated RPiOS Buster w/ Desktop OS.

Joe Schmoe
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 2:16 pm

I am running with a 5V 10A industrial supply with adjustable trim and still had power problems until I made my own cable with 22ga wire.
+1

Ya know... Thousands of years ago, when I was first mucking around with setting up Unix machines, my mentor gave me this piece of sage advice: It's always the cable.

It was true then, and it is true now.

I cannot recommend strongly enough this cable:

http://www.monoprice.com/Product?c_id=1 ... 1&format=2

$1.11 each

I had the same problem as you and others where untilI got a good cable, it didn't matter how good a power supply I had - still got brownouts. Now, I'm powering two Pis off a single powered USB hub; it all works fine, using these Monoprice cabls.
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

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rleyden
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 2:22 pm

klricks wrote:
rahlquist wrote:I have a nice 12v 2A supply from a router I am using. Combined with http://www.ebay.com/itm/310813369212?_t ... EBIDX%3AIT

I still see blinking power LED. No matter what I do I cant seem to totally escape it.
I am running with a 5V 10A industrial supply with adjustable trim and still had power problems until I made my own cable with 22ga wire.
I've had good luck with the step down converter with an adjustable output voltage, http://www.ebay.com/itm/1-DC-DC-Buck-Co ... 2a3cdecf73.
I set the output roughly to 5v then plug in the Pi fully loaded (camera, wifi, etc.) the adjust the voltage under load to 5.25 V. Where I previously had random issues running headless remote Pi, it is now rock solid. Previously, I had problems even using a re-purposed ATX PC power supply which put out a steady 5V at the source.
I found this cheap USB meter extremely handy to diagnose power supply issues, http://www.ebay.com/itm/USB-Charger-Doc ... 1e8cf836ae .
Some of the cheap step down converters now have a built-in voltmeter.
Note, I feed at the GPIO pins and measured at he PI USB. I no longer feed power through the micro USB except when using a "bare" Pi.

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Offcenter
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 3:24 pm

My Pi has been running for a year and a half continuously from a 12 volt supply using a UBEC.
http://www.hobbyking.com/hobbyking/stor ... ction.html
The UBEC will take any input voltage from 5.5 to 23 volts and put out a rock solid 5 volts.
They come from the radio controlled airplane world. No one would trust a thousand dollar model
airplane to junk parts, so these things are made well. Less than five dollars.
George in New Jersey.
(learning a little bit every day.)
(and darned confused most of the time!)

cptdodgerm
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 9:57 pm

rleyden wrote:
I've had good luck with the step down converter with an adjustable output voltage, http://www.ebay.com/itm/1-DC-DC-Buck-Co ... 2a3cdecf73.
I set the output roughly to 5v then plug in the Pi fully loaded (camera, wifi, etc.) the adjust the voltage under load to 5.25 V. Where I previously had random issues running headless remote Pi, it is now rock solid. Previously, I had problems even using a re-purposed ATX PC power supply which put out a steady 5V at the source.
I totally agree on this. I cannot recommend these hard enough. They are perfect for ANY device that requires up to 30v at 3A. I use these on projects for my Pi, RC projects, camera's, mobile phone chargers, CCTV..plus much much more.

Rog

Joe Schmoe
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Re: Powering PI from 12v DC

Tue Mar 10, 2015 10:10 pm

cptdodgerm wrote:
rleyden wrote:
I've had good luck with the step down converter with an adjustable output voltage, http://www.ebay.com/itm/1-DC-DC-Buck-Co ... 2a3cdecf73.
I set the output roughly to 5v then plug in the Pi fully loaded (camera, wifi, etc.) the adjust the voltage under load to 5.25 V. Where I previously had random issues running headless remote Pi, it is now rock solid. Previously, I had problems even using a re-purposed ATX PC power supply which put out a steady 5V at the source.
I totally agree on this. I cannot recommend these hard enough. They are perfect for ANY device that requires up to 30v at 3A. I use these on projects for my Pi, RC projects, camera's, mobile phone chargers, CCTV..plus much much more.

Rog
This looks very cool, but the page (at the link given above) is short on details.

Can you say more about how it works? What is the input?
Does it come with any sort of documentation?

For about $3 total (including shipping), I could just take a chance on it, but I've gotten some things this way with zero docu and have not been able to do anything with them.
And some folks need to stop being fanboys and see the forest behind the trees.

(One of the best lines I've seen on this board lately)

cptdodgerm
Posts: 28
Joined: Fri Feb 13, 2015 11:33 am

Re: Powering PI from 12v DC

Wed Mar 11, 2015 9:59 am

Joe Schmoe wrote:
cptdodgerm wrote:
rleyden wrote:
I've had good luck with the step down converter with an adjustable output voltage, http://www.ebay.com/itm/1-DC-DC-Buck-Co ... 2a3cdecf73.
I set the output roughly to 5v then plug in the Pi fully loaded (camera, wifi, etc.) the adjust the voltage under load to 5.25 V. Where I previously had random issues running headless remote Pi, it is now rock solid. Previously, I had problems even using a re-purposed ATX PC power supply which put out a steady 5V at the source.
I totally agree on this. I cannot recommend these hard enough. They are perfect for ANY device that requires up to 30v at 3A. I use these on projects for my Pi, RC projects, camera's, mobile phone chargers, CCTV..plus much much more.

Rog
This looks very cool, but the page (at the link given above) is short on details.

Can you say more about how it works? What is the input?
Does it come with any sort of documentation?

For about $3 total (including shipping), I could just take a chance on it, but I've gotten some things this way with zero docu and have not been able to do anything with them.
This is a link to a UK seller of the same part http://www.ebay.co.uk/itm/5pcs-LM2596S- ... 20e0c81282

If you scroll down you will see if gives alot more detailed information. They do not come with an instructions because due to their simplicity, it is expected that the people who purchase them know what they are and how to use them.

It is quite simple really, you have voltage in and voltage out. On my units I use old laptop PSU's that had damaged connectors on them. I cut the end off and soldered the + and - to Vin + and Vin -, then whatever device I planned to use I would solder the devices's + to Vout + and the - to Vout - then with a multimeter on DC setting, you places the probes on the Vout solder joints and adjust the trimmer with a flat blade screwdriver until you see the output voltage on the multimeter adjust to your desired voltage.

There is a better version but just slightly bit more expensive http://www.ebay.co.uk/itm/LM2596-LED-Vo ... 2588ad27ba This has the advantage of having LED's to show both input and output voltages which does away with the multimeter, a button that switches between input and output voltages and screw terminals to connect the wires to instead of having to solder them.

Due to both having a maximum output of 3A ( under heavy load and requiring a heatsink), they are perfect for your everyday small voltage needs.

Rog

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Re: Powering PI from 12v DC

Wed Mar 11, 2015 10:10 am

http://www.banggood.com/USB-Step-down-P ... 5420130630 <- I've used those in the past with no issues - [got one in my shed which runs of 12V and powers a few things including a RPi ]
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