Help needed using a AC DC converter.

[madnomad]

Hi guys, I recently discovered on the following thread that its possible to connect an AC-DC converter to a DC source and its fine (read from 4th post down):
https://www.endless-sphere.com/forums/viewtopic.php?f=2&t=50458
So I instantly went to my box of old computer bits and found a couple of converters that I think may be suitable, and planned to use this one:

The label says it puts out 12v and 5v. So am I right in thinking that I could use this to power 12v AND USB devices directly from my 56v battery?
It had a 6 pin connector, and the diagram in the above photos says that 2 pins are for GND, 2 are for +5v, and 2 are for +12v.
I cut off the connector to reveal 3 cables, red, yellow and white. I have tried testing each with my voltmeter but the readout only flickers briefly and then goes back to 0, I assume thats because the converter automatically gives out the right power to whatever its connected to? Is that right? (Sorry I'm still quite new to all this).
So I'm thinking I need to have 2 interchangeable plugs to go on the end of the cable- a female USB and a female 12v plug, or is it possible to somehow have both connectors on the end of the cable? Could someone tell me how I would go about connecting it up? Sorry I'm quite new to all this so please dont worry about sounding too patronising. Laymans terms would be great.

 

[madnomad]

This is AC Mains powered and not DC to DC compatible.

My advice would be to read this topic that is dedicated to converters.
http://www.ittsb.eu/forum/index.php?topic=965.0

Yes I know its AC. But as I said, I read on a post here that you can use AC converters. I actually posted the wrong link earlier though, the thread was actually this one (read the 4th post down):
https://www.endless-sphere.com/forums/viewtopic.php?f=2&t=50458

It says:

This has been discussed alot of time on E-S...

if you take time and search a bit you will find that we use some regular AC-DC 12V 5A transformer ( switching power supply) availlable from ebay for about 10$ shipped or 5$ at any local PC surplus store.

Few years ago i discovered that these AC input power suppy ALSO accept DC at the input and with voltages as low as 25V sometime! I made some post about that :wink: i'm using this method for all my ebikes projects now. What is great is that they can sometime take any voltages from 25 to 350Vdc at the AC normal 120V input

http://www.ebay.com/bhp/12v-5a-power-supply

Doc

 

[friendly1uk]

This is AC Mains powered and not DC to DC compatible.

My advice would be to read this topic that is dedicated to converters.
http://www.ittsb.eu/forum/index.php?topic=965.0

You don't get it.


Madnomad, you will have to try. Some will, some won't. The ones that won't can often be modified, but this is quite complex if you have no electronics background

 

[madnomad]

Madnomad, you will have to try. Some will, some won't. The ones that won't can often be modified, but this is quite complex if you have no electronics background

If it doesn't work then I've got a few more I could try. But I don't really know where to start with this one at the moment. I have 3 wires on the output end- red, white and yellow. Does anyone know how I would connect these to a female USB plug and a 12v plug?

And another question- if there are only 3 wires, then why was there 6 pins in the plug I took off. It was one of these btw:

 

[Ykick]

I have 3 wires on the output end- red, white and yellow. Does anyone know how I would connect these to a female USB plug and a 12v plug?

And another question- if there are only 3 wires, then why was there 6 pins in the plug I took off. It was one of these btw:

Use DVM to probe wires and sort out Voltage channel and polarity. GND (ground) will be shared the remaining 2 wires will be +5/+12VDC. Red is likely one of the later but just use DVM to determine.

Manufacturers often use what's commonly available for connectors. Although it probably doesn't need all 6 pins to carry the power it doesn't hurt anything to connect them paired as shown on the label.

 

[friendly1uk]

The supplied diagram is enlightening. It shows the pins are paired. Chop the plug off with enough cable still on it to strip them. Then use a continuity tester and the supplied diagram to see which colour is which.

It's going to be black ground, red 12v and yellow 5v. I'm fairly confident of it.

Equally as useful a method as ykick said, but without wasting electric lol

 

[madnomad]

Awesome, cheers guys Okay I'm going to have a go, seems straight forward enough. Just a quick question though- any idea why this converter would need to convert to two different voltages? It's from an external hard drive which would use 12v. It wasn't designed to power anything else so what the point in designing it to supply 5v as well?

 

[izeman]

3.5" disk drives need 5v and 12v. If that is the case it may be exactly the opposite of what friendly1uk said as computers use red for 5v and yellow for 12v . But whatever colors the cable uses means noting per se. To be sure you MUST measure the voltage with a DMM.

 

[friendly1uk]

Good call lol
I'm sure I have heard it somewhere before you know. Just before my post somewhere. Can't think where lol

 

[madnomad]

Tried charging my phone but it didn't work. Guess it doesn't have enough amps.

 

[100volts+]

The old converters might not work, (the label on your converter is yellow.Is it an old converter?) but the new ones do. Here is a pic of me powering my light with one. I have a 30s system. (125v)

 

[madnomad]

Tried charging my phone but it didn't work. Guess it doesn't have enough amps.

It is wiser to accept that you were mislead by a word coming from some one who has poor understanding too, about electricity and electronics How-To.
Bottom line is that you wanted to be mislead, because you was in denial to spend real money for a true working solution.

Wow, I wanted to be mislead? Well, not really dude. For a start, I don't actually know that it wouldn't have worked, because I didn't even get to the stage of connecting it to the battery. It wouldn't even charge my phone while it was plugged into the wall, so I think it was because it didn't have enough amps. Secondly, I took the word of quite a lot of people who say this will work. Just because I decided to have a go anyway after you told me it wouldn't work, and just because someone else told you you don't get it, doesn't mean that you should start psychoanalyzing my reasons, and you shouldn't feel offended either. Bottom line is, I wanted to have a go so I could learn something, and also potentially save myself and people on this forum money because they won't have to spend $80 on something they may already have lying around in their attic somewhere. Whats wrong with that?

 

[madnomad]

The old converters might not work, (the label on your converter is yellow.Is it an old converter?) but the new ones do.

Its just the light in the photo making it look yellow but its actually white. But yeah it is quite old, probably about 8 years old. Originally I said its from an old external hard drive, but I've just realised its actually from an old external hard drive enclosure which you can put in an internal SATA or PATA hard drive to turn it into an external hard drive.

 

[Ykick]

Tried charging my phone but it didn't work. Guess it doesn't have enough amps.

It is wiser to accept that you were mislead by a word coming from some one who has poor understanding too, about electricity and electronics How-To.
Bottom line is that you wanted to be mislead, because you was in denial to spend real money for a true working solution.

Wow, I wanted to be mislead? Well, not really dude. For a start, I don't actually know that it wouldn't have worked, because I didn't even get to the stage of connecting it to the battery. It wouldn't even charge my phone while it was plugged into the wall, so I think it was because it didn't have enough amps. Secondly, I took the word of quite a lot of people who say this will work. Just because I decided to have a go anyway after you told me it wouldn't work, and just because someone else told you you don't get it, doesn't mean that you should start psychoanalyzing my reasons, and you shouldn't feel offended either. Bottom line is, I wanted to have a go so I could learn something, and also potentially save myself and people on this forum money, so they don't have to spend $80 on something they may already have lying around in their attic somewhere. Whats wrong with that?

Iggy list (ignore, foe, etc.) is your friend here. Of course, when somebody quotes the "ignored" as you did here, it's not so ignored....

As far as OP, gotta keep trying wall warts until you find one with the capability to run off high voltage DC.

 

[dnmun]

if you take the screw off of the cover and open it up so we can see how it is organized we can see if it will work on your battery. what voltage will you use on the input? you have to ignore people who don't do this stuff. most of us have done this on one or more of the AC adapters, or wall warts as they are called.

it may not be possible to make one set up for dual voltages to work. see if you can find one set up for 5V only.

 

[izeman]

Tried charging my phone but it didn't work. Guess it doesn't have enough amps.

Just try a different power supply. And ignore our Greek pessimist's postings. Many including myself have proved that it does work. But not every power supply works the same. My success quote is better than 50%.

 

[teklektik]

Ignore KGR - a wellspring of bad advice and discouragement - usually delivered with belittling remarks...

It wouldn't even charge my phone while it was plugged into the wall, so I think it was because it didn't have enough amps.

Possibly, although if you were trying to charge an Apple product via a USB connector, you also need to apply voltages to the D+ and D- data pins to tell the Apple device how much current it can draw or it won't accept a charge at all. A quick Google will bring up sample circuits.

• This Instructable shows examples of setting pin voltages for 500ma and 1000ma capable chargers.
  Only needed for Apple stuff.
  EDIT - The Instructable also claims that the Samsung Galaxy has similar requirements....
  Also see this page for other devices.

As far as the viability of the the general strategy, this technique is well tried and proven. I think this is the original thread from 2007 about this idea by fechter (one of our respected engineers) along with some typical test results. As others have suggested, you may need to try another unit to get one that will do the job for you.

 

[madnomad]

if you take the screw off of the cover and open it up so we can see how it is organized we can see if it will work on your battery. what voltage will you use on the input? you have to ignore people who don't do this stuff. most of us have done this on one or more of the AC adapters, or wall warts as they are called.

it may not be possible to make one set up for dual voltages to work. see if you can find one set up for 5V only.

It doesn't seem to have any screws in it. I've got a load more converters in my attic that I'm going to try. I haven't really got any need for 12v at the moment so I guess I'll forget about dual voltage controllers for now. Mainly just want 5v for phones and urban lighting. Got one of these for my offroad lighting:
http://www.ebay.co.uk/itm/191304896814?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Hasn't arrived yet though...

Possibly, although if you were trying to charge an Apple product via a USB connector, you also need to apply voltages to the D+ and D- data pins to tell the Apple device how much current it can draw or it won't accept a charge at all. A quick Google will bring up sample circuits.

• This Instructable shows examples of setting pin voltages for 500ma and 1000ma capable chargers. Only needed for Apple stuff.

As far as the viability of the the general strategy, this technique is well tried and proven. I think this is the original thread from 2007 about this idea by fechter (one of our respected engineers) along with some typical test results. As others have suggested, you may need to try another unit to get one that will do the job for you.

No, its a Samsung Galaxy S2, but I'm thinking of upgrading soon because I plan to plug in a USB endoscope camera so I can use my phone as a rear view mirror, and external cameras aren't compatible with the S2. Is it just Apple I need to avoid? (which I've always done anyway )

Cheers for all the help guys, this has all been really useful. I'll let you know how it goes once I try out some more converters.

 

[teklektik]

No, its a Samsung Galaxy S2, ....

Oops - I just noticed that that Instructable claims that in addition to Apple products, the Samsung Galaxy also requires the same finagling with the data pins.
Sorry, 'bout the slip-up - but this is actually good news....

• Here's another page with additional voltage details for various devices.

 

[madnomad]

No, its a Samsung Galaxy S2, ....

Oops - I just noticed that that Instructable claims that in addition to Apple products, the Samsung Galaxy also requires the same finagling with the data pins.
Sorry, 'bout the slip-up - but this is actually good news....

• Here's another page with additional voltage details for various devices.

Nice info, reading through it now, cheers!
Just a thought, but has anyone tried wiring a Samsung/Apple charger to the CA to see if that can accept DC?

what voltage will you use on the input?

It's a 58v battery and the CA puts out 56v

 

[cycborg]

The Greek is professional industrial electrician

KGR: Oh, Diploma, once again these ES morons believe that their reality trumps my superior understanding.

Diploma: With what device do they torment you this time?

KGR: They put their faith in these false objects they call switching power supplies.

Diploma: Ah, I have heard these words spoken by greater Diplomas, could they possibly exist?

KGR: Oh, Diploma, anything you have not taught me cannot possibly exist!

Diploma: Of course! Those poor ES morons, they ride their bicycles about in the dark, believing their switching power supplies allow them to emit light, while we know that this light is only in their imagination, and they will be struck by cars at any moment!

KGR: Right you are, Diploma! I must return to my tedious task of straightening out these ES morons.

 

[izeman]

Lol. That was a good one

 

[100volts+]

I posted a similar thread last week. I got ok results from an 8.4v .5a charger so I ordered an 8.4v 2a it works great. 4.99 on ebay I think that was too much. but it was free shipping from china.
http://endless-sphere.com/forums/viewtopic.php?f=1&t=65574

 

[izeman]

Jehovah!!! Something that can't be MUST not be. This must be black magic!

 

[madnomad]

Just a thought, but has anyone tried wiring a Samsung/Apple charger to the CA to see if that can accept DC?