Need Help converting 110v AC to 12v DC

Reply

  #1  
Old 11-29-07, 10:27 AM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
Need Help converting 110v AC to 12v DC

Hello.. here is my situation..

I need to take a 110V wire, one in with a normal male plug, the other end just raw wires.. and somehow convert that (raw wires) into a 12v DC male. (the kind of plug that you would plug into a laptop to charge). I don't want to use a huge converter, like laptops use.. it should be small and not take up an big amout of space.. Most of the converters like you buy at Radioshack are about 3"x3" and require a female 110v plug.

Any suggestions.. (I do have experience with soldering on electrical boards, so that's not a problem..)

Thanks for any ideas..
 
Sponsored Links
  #2  
Old 11-29-07, 11:45 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
What you want to do sounds unsafe. First the 12v plug is probably not rated for 120v. Obviously 120v can't be fed into a 12v DC circuit with out the converters you don't want to use. Tell us what you are trying to do and perhaps someone can help.
 
  #3  
Old 11-29-07, 12:52 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
The only way to go from 120V AC to 12V DC is to use a transformer and rectifier which are the components of laptop and other such power supplies.
 
  #4  
Old 11-29-07, 01:26 PM
core's Avatar
Member
Join Date: Jan 2007
Location: Des Moines, IA
Posts: 1,127
Received 0 Votes on 0 Posts
Here's one part I don't understand:

Originally Posted by dirtmcgirt79 View Post
Most of the converters like you buy at Radioshack are about 3"x3" and require a female 110v plug.
Well yes, they require a female 110v socket, the one in your wall! But so would your device... (??)

As has already been said, you need to use a proper power supply. The little wall warts that they sell at radio shack are about as small as you're going to get. The ones like you see for cell phones are a _bit_ smaller I guess and you could probably find something along those lines. You just can't expect to pack in all that circuitry (especially the transformer) in something the size of your thumb!

Also, in general for these things the smaller the device is the less capacity it has. Don't expect to power something like a laptop with a wall wart. There's a reason those laptop ones are bricks.
 
  #5  
Old 11-29-07, 01:49 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
The OP wants to somehow eliminate the converter. There is no way to do that. The AC must be changed to the proper voltage for the laptop.
 
  #6  
Old 11-29-07, 06:48 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
Hey again..

thanks for all of the comments. I understand what you all are saying.. I know I made myself sound dumb.

Ok, Here is the deal. My brother has an issue with an employee at his business. Well in short, he thinks that she may be stealing money. But he can't prove it yet. So we thought that we might be able to plant a nanny cam in a clock that is in her work area. This clock already runs on a 110v AC. And most pinhole cameras run on 12v.

So I was trying to figure out a way to just have one wire running from the clock, instead of one to power the clock and one to power the camera. And there isn't a ton of room in the back of the clock to tuck an extension cord and 12v transformer to power the camera.

I thought that there may be some kind of smaller converter that could be just hard wired in. But I'm assuming not...

Thanks for all of your help with this...
 
  #7  
Old 11-29-07, 07:00 PM
core's Avatar
Member
Join Date: Jan 2007
Location: Des Moines, IA
Posts: 1,127
Received 0 Votes on 0 Posts
Actually the room behind the clock isn't a huge issue. You're going to have an extra wire leading to the clock anyway because of the video signal, right? Right.

So instead of trying to put a largish converter behind the clock put the converter somewhere else out of sight, and just run a small wire for the 12V. Now you have two extra wires running to the clock. (But one was acceptable in the first place, so two shouldn't be an issue?)

By the way most of these cams can run on 9V batteries too. You certainly won't get many hours of life but it works.

Otherwise I think you may just need to get low-tech: Find a better place to hide that camera.
 
  #8  
Old 11-29-07, 07:03 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
Don't hide the camera at all. I am no legal expert, but I believe that unless you tell employees that they may be monitored that you cannot do it. Period.
 
  #9  
Old 11-29-07, 07:08 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
that's a good idea about the batteries.. I actually thought of this, but then I figured that they probably wouldn't last a full shift, and could possibly miss the moment that this happens.

But I do some more research.. We were planning on using a wireless setup for the video part, so no video cable.

But you know.. you see these nanny cams in clocks online that work this way, fully functional, with one power cable coming out. So I figured it couldn't be too hard.. the ones online are pretty darn expensive too and probably have crappy cameras in them..
 
  #10  
Old 11-29-07, 07:15 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
Well, it's funny that you say that.. because he did tell all of the employees that they were going to be monitored a few months back... thinking that this would deter her.. but it didn't seem to work.. Maybe they thought that it was a joke or she just thought that she is too good to get caught.
 
  #11  
Old 11-29-07, 07:20 PM
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
Be very careful how you proceed. You might want to speak with a lawyer who specializes in this area.

If you don't do things just right (and legally), you may not be able to use any evidence you collect. You certainly don't want to obtain proof someone is stealing and then not be able to prosecute or even fire them for it.
 
  #12  
Old 11-29-07, 07:25 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
understood racraft.. thanks for your help..
 
  #13  
Old 11-29-07, 07:26 PM
core's Avatar
Member
Join Date: Jan 2007
Location: Des Moines, IA
Posts: 1,127
Received 0 Votes on 0 Posts
Pricy, yes they are! Like $200.

And you were planning on rigging up one yourself? That must be one BIG clock you got there. All my wireless transmitters are well, rather large for that application. And you seem to have room for a battery or two on top of it.

The companies that make these things have the advantage of being able to select the clock that they use. I haven't tried taking my clocks apart, but I'd bet you'd be able to find a 8-12v point somewhere inside many modern electronic clocks. With a little electronics knowledge one can certainly create one if there isn't one already.

To take care of the legal issues just put little stickers on the front entrance saying premisis under 24hr video surveillance or what not. Nobody pays attention to those things anyway, but it covers your rear. If you really wanted to get sneaky, that same day put up an OBVIOUSLY-fake camera on the outside door. The employees will assume the signs went up because of that scare-toy.

You may not film people where they have a "reasonable expectation of privacy". (Powder room, etc.) But an employee at their work area (especially if handling money) does not have a reasonable expectation of privacy there, if signs have been posted.
 
  #14  
Old 11-29-07, 08:58 PM
Member
Thread Starter
Join Date: Nov 2007
Posts: 18
Received 0 Votes on 0 Posts
Actually.. there are wireless transmitters that are about 1 1/2" by 1 1/2". I think that's small.. the receivers are a little bigger than that, but that isn't a problem...

but when I say pricey I mean $500-$600. I'm sure a $200 clock is probably going to have a terrible camera inside..

We probably won't do this after all.. I don't want to flip this around so that we are the bad ones in this situation, by putting up cameras... It's just a shame that more people can't be honest..
 
  #15  
Old 11-30-07, 05:05 AM
Member
Join Date: Apr 2007
Location: Near Buffalo, NY
Posts: 4,239
Received 0 Votes on 0 Posts
"Reasonable expectation of privacy" means you can't put a camera in a rest room or a locker room where people change clothes. Everywhere else is fair game. Send a memo to every employee and tell them about the new video system.

When I had my video production company one of our clients was the security department of a large supermarket chain. They put a camera with a smoked-glass dome in plain view over the customer service counter, where large amounts of cash changed hands. One of the employees would hide her hands from the camera's view when she was pocketing cash out of the drawer. She didn't know about the hidden second camera that clearly showed her hands from a different angle.

One day they took her to the security office and showed her the tapes. It never needed to go to court. Just the threat of legal action made her pay the money back. And of course, she was fired.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: