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Power Supply for LCD and Camera

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LordGus

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Hello, I read the Beginners power supply post above and that left me a little lost. So simply put I want to get a portable power supply that is a 12V DC input for power. I want to see what is out there and I am a bit lost on what to buy.
I dont want to lug around a car batters that would be so not cool. So what can produce a 12v dc power. I seen a lot of AC to DC but this project will be outdoors so I wont have a house to plug this into.

now I found this battery hack
https://www.instructables.com/id/12-Volt-Battery-Hack!-You_ll-be-Surprised.../
would getting a bunch of batteries together and then combining them into 1 power supply work or is that just a bad idea and would not work at all? or would just getting a 12v battery work? like this one
https://www.batteryjunction.com/duracell-2012.html
Or is there something that I am missing with this?
Thanks for any help
 
If you want help acquiring (or designing) a power supply, you've got to give us some crucial information, which I don't see in your post:
  • Input voltage
  • Input AC or DC
  • Output voltage (we'll assume DC)
  • Output current (amps)
  • What's being powered (light/motor/amplifier/???)

If you supply this info, it'll make things a lot easier, so we don't have to play "20 questions".
 
What I am powering
A camera like this one
**broken link removed**
and a lcd screen from here
**broken link removed**

Input Voltage: ....... Um I dont really know

It requires a DC input to power it so I would think DC for the input

output voltage would be DC i think

Output AMps: ..yet again I dont know

I am new to projects like this so I have yet to get voltage and currents down sorry about that.
 
You seem to be a little confused about "input" and "output" here.

Input is the input to the power supply; output is the output to your camera.

Since you said you want to use this outdoors, it sounds like you're going to want to use batteries (the only other option would be to use solar panels). Any idea of what kind of battery you want? You said you don't want to lug a car battery around (understandable!). Do you want us to suggest a suitable battery for you?

Looking at those links, the camera appears to consume 300mA, and the LCD draws aboiut 600mA (most of that for the backlight: the panel itself only draws about 60mA), for a total of about 1 amp. So your requirements are pretty modest.

Just off the top of my head, I'd suggest a 12-volt battery, maybe a small SLA (sealed lead-acid) unit, like those used in emergency exit signs and such. You'll also need a 5 volt regulator to run the LCD, which is a very simple circuit based on a single voltage-regulator IC (chip). Easily built by a DIYer.

You could also use 8 rechargeable "D" cells (large flashlight-sized 1.5V cells) to get 12 volts. Several ways to skin this cat ...

Here's how I would do it, using "D" cells:

**broken link removed**

The cells are split into a group of 6 (9 volts) and 2 (3 volts). The cam gets the full 12 volts. The LCD is fed from a 7805 voltage regulator, which supplies a steady 5 volts. (You might be able to split the cells 5/3; you need to make sure the voltage regulator has a high-enough input voltage as the cells lose charge, or use a "low-dropout" regulator.)

This could be put inside a metal or plastic project box with connectors to plug your devices into.
 
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Looking at your two links, you won't be able to just 'plug them together'.
You might need to look at a 'headrest LCD' or similar, the kind with a direct video in socket.
 
Thanks I think I will try what your suggestion is it sounds like I can manage that:
So for a part list I would need the;
8 D battery the 1.5volt kind
Do I need the 7805 voltage regulator or does the LCD have one?
The D battery connecter thingys that hold the battery
Lots or wire and solder so I can screw up.(a lot)

"Looking at your two links, you won't be able to just 'plug them together'.
You might need to look at a 'headrest LCD' or similar, the kind with a direct video in socket."

They thankfully do, you have to call them up and it comes in a nice "you dont have to do anything" kit that accepts an RCA feed from the camera, I also think it accepts VGA as well I think.
 
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Thanks I think I will try what your suggestion is it sounds like I can manage that:
So for a part list I would need the;
8 D battery the 1.5volt kind

All "D" cells are the "1.5 volt kind". (Well, except those that aren't, like nicads, which are 1.2V.)

Do I need the 7805 voltage regulator or does the LCD have one?

You need to buy one. It'll set you back a whole 29 cents at Jameco.

The D battery connecter thingys that hold the battery
Lots or wire and solder so I can screw up.(a lot)

AKA battery holders. Plus don't forget the electrolytic capacitor.

You won't need that much wire & solder; you'll get the hang of it.
 
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The camera needs a 12V regulated power supply. But 8 alkaline battery cells are not regulated and their voltage starts at 12V then slowly drops to 8V.
You will need 14 alkaline battery cells to make 21V when new which drops to 14V over their life and they feed a 12V regulator that has a huge heatsink. If the LCD needs 5V then you need a 5V regulator with another huge heatsink. The datasheet for the battery cells shows how long they will last.
 

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Have video cameras EVER used old-fashioned and heavy lead-acid batteries?
Usually they use a powerful lightweight lithium battery that has a charge that lasts for a long time.

The small but heavy lead-acid batteries you show will last maybe 6 minutes to 12 minutes if they were recently fully charged.

Hobby stores sell lithium batteries and chargers that are designed to power radio-controlled model cars, boats and airplanes.
 
Ok so here is what I have so far I think this is what I should do see attachment.
Do you think this would work?

It would work, but with major problems. Main one being the need for huge heat sinks on the voltage regulators, as has been previously pointed out.

Keep in mind that a linear voltage regulator works by shedding the excess voltage (the difference between the input and output voltages) as heat. Heat's gotta go somewhere, or it'll cook the regulator. Plus, you're wasting precious battery power heating things up.

I was thinking if I need 21v then could I just use 2 12v battery like this one?
https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_318844_-1

If you're going to use a 12V SLA battery, I don't see why you can't run the camera directly from it (after all, it takes 12 volts), then use a 7805 regulator to provide the 5V supply.

So would that battery be compact enough for you needs?
 
This is getting complicated, ok first off is this what is meant by a heat sink? https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_326596_-1 I took apart my xbox360 once and that silver thing on the mother board with the fin looking thing was that the heat sink?
for the battery I could just use the one 12V battery and then the 7805 regulator for the LCD. That seams simple enough
A battery that size would actually act as a counter weight to my sweet Steadicam that I am working on.
3.8"L x 1.7"W x 2.1"H would actually fit on my belt on the other side so that would be really nice.
 
This is getting complicated, ok first off is this what is meant by a heat sink? https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_326596_-1 I took apart my xbox360 once and that silver thing on the mother board with the fin looking thing was that the heat sink?

Yepper, that's a heat sink. I salvage mine from electronics people put out on the curb, but that's just me. They're cheap enough.

for the battery I could just use the one 12V battery and then the 7805 regulator for the LCD. That seams simple enough
A battery that size would actually act as a counter weight to my sweet Steadicam that I am working on.
3.8"L x 1.7"W x 2.1"H would actually fit on my belt on the other side so that would be really nice.

Why not try it and see how it works? Look at it this way: you can put it together and see how it works, checking the 7805 to see how hot it gets. If it gets too hot to touch, then you either need a bigger heat sink, a bigger chip (i.e., a 5-volt regulator that can handle more than 1 amp), or both. In either case, you'll be out, what? about a buck.
 
Ok One more thing before I start ordering all this stuff. I was doing some research on power supply and found this amp thing so the camera that I am looking at uses 100-300mA and the lcd uses some amps too I could not figure that out by looking at the data sheet. A lot of info that means nothing to me. Then looking at the battery one had 12 APM-Hrs which I can only assume is 12 amps per hour or some thing like that (big guess here)
My question here is do I have to worry about the amps for the battery or is it one of those dont worry about until you shock your self moments?
 
The battery rated at 12Ah can supply 1.2A for 10 hours when its voltage has slowly dropped to 11.0V. The camera needs a 12V regulated supply so it might not work when the voltage is only 11V.
 
The battery rated at 12Ah can supply 1.2A for 10 hours when its voltage has slowly dropped to 11.0V. The camera needs a 12V regulated supply so it might not work when the voltage is only 11V.

Ah. Ok so I might get 1 12v and then a supplementary battery so I can use it for more than 10 hours so I might use 1 12v rechargeable battery and one 9V battery the little square ones. So I can just swap out the 9V one during the day if it stops working properly. Would that work?
 
The voltage and current from a little 9V battery are much too low to power your camera.
We don't know how long a heavy lead-acid battery will power the camera since it is supposed to be powered from regulated 12.0V. It might mal-function after a few hours when the voltage drops to 11.8V or 11.5V.
 
So the safest bet would be to have 2 12v battery then not worry about anything then I I need more power by switching up a camera or adding some leds to it latter on then I will have enough power for everything
 
When you put more batteries in parallel, you increase the amount of current (amps) you can draw; this can put off the time where the battery voltage drops, but not forever.

The problem with using a 12-volt battery on a device that runs on 12 volts is that over time, the battery voltage will drop below 12 volts, as Audioguru pointed out. At some point, the voltage will be too low for the device (camera, whatever) to function properly. How low can you go? We don't really know; the only way to really find out is to try it. It probably won't damage the camera, but at some point, it will start exhibiting flaky behavior, or will stop working altogether.

Ideally, you would use a voltage source (battery) that's higher than the voltage you need by some significant amount (say, 14-15 volts), then regulate the voltage down to 12 volts. This will give you a longer run time before the battery voltage "sags" to an unusably low level.

Does that make sense?
 
Yes it does so I will have to look for a battery that has a higher volt than 12. So probably the best way is to link several batteries together to make a 15 volt battery instead of getting one or 2 12v battery.
 
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