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hi all, i bought an aiptek pocket projector v10, The unit includes a USB power adaptor that pumps out 5v at 2a (!) That is how much juice it takes to run the unit while plugged in to AC power. Yes, it will charge (slowly) from most any common USB port, it will not fire up and run without 2000mh behind it. It detects low powered USB connections, and goes into 'flash disk / slow charge mode', thinking it's hooked up to a computer for loading stuff to it's internal memory. So - what to do? I want to run it via usb from a 12v battery, how can i achieve this?
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Los Angeles
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 7:59 AMYou might try a DC to AC converter designed for use in Cars such as (www.radioshack.com/product/index.jsp
Pulling 2A from a battery isn't likely to last very long. -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 11:02 AMIt wouldn't be pulling 2 amp from the battery, more like .83 amps. because you're converting to 5 V from 12 V The device " uses" 5v @ 2 amp
A usb to cigarette lighter adapter with an output of 5 v ( standard) would do the job. A comparatively large ( to the projectors batteries) car battery would last a very long time. A cell phone store would be a good place to check.
How well does the little thing work ? -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 11:42 AM"A usb to cigarette lighter adapter with an output of 5 v ( standard) would do the job."
i have one and it doesnt work, it charges but i cannot turn it on. i want to run it while plugged in like i do when on the 120 adaptor. seems like this thing needs to see the same power signature the 120 volt to usb adaptor has, either that or they are pinned/wired differently. am not sure yet.
hey dan this thing is the cats meow and i am only lpaying back from internal video i hear it looks twice as good using an external source for the video, the 640x480 is awesome, i have a 50 inch tv when it gets dark using the wall. i just want a drive in theatre for camping sooooooooo???? -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 12:34 PMMany Electronics are sensitive to the electrical cycles, 110 / 120v is 60 cycles, I believe a converter also converts to 60 cycles as well as to12 v.
SO charging at non 60 cycles 12 v. would work, but you may need the 60 cycles to operate. Orrrr. the projector may not be made to operate while charging off of a USB connection. and if you have it plugged in it may " think" it's charging. Check your operators manual.
Sounds like a small 110 converter for the cigg lighter, with your 120 adapter plugged into it will be the way you go. A deep cycle Marine would be the way to go. A " marine starting / deep cycle" could start your car as well as provide the extended use. This is what I always go with. Just bought one the other day from O'Rillys for $60.00 Less that their standard cheep car batt.
PS. you cannot use a "deep cycle only " batt to start your engine. -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 1:11 PMthe only problem i have with that is to ramp up to 110 then back down to 5v is super inefficient and a waste of rescources. i am currently working on getting an battery isolater and running a deep cycle marine battery for "entertainment" only.
yes dan, it would probably work that way but......mebe i need to hack it from the battery then, i got an extra battery pack with it, if i gutted out a battery pack then wired it to provide 3.7 volts from the 12v source do you think it would work then? i really dont want to step up to 120v just to get 5v or in the case of a battery hack 3.7v...........????? -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 3:56 PMI'm pretty sure you will still have to deal with the difference in cycle rates. I believe the 12 v dc. to 120 v AC will give you the 60 cycles you need. You can't just step the voltage down.
I'd find some old guy, or geek at a radio shack to confirm. then buy what you need elsewhere, if you can. R.S. can be a little pricey, but then they might be the easiest option also -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 5:23 PM“I'd find some old guy, or geek at a radio shack to confirm.”
Well, let's see, I'm 55, have been “playing” with electronics and computers since the PDP-8 and Heathkit days, and work at Radio Shack. I was just going for the fast solution.
If I was doing this I'd put a step down resistor in and wire it to the appropriate USB plug. Be sure that the resistor can handle the current. You will need 3.75 ohms to drop 12v to 5.5v. 1 – 100 ohm and 3 – 10 ohm resistors wired in parallel will provide a drop from 12v to about 5.48. That should be close enough.
Of course your mileage will vary depending on the battery charge. THIS IS AN UNREGULATED POWER SUPPLY. I would be sure that there is open space between the resistors so that they don't over heat or electrically couple.
There are 100 and 10 ohm resistors rated at 10 watts in the drawers at Radio Shack. Total cost is about $6 plus tax.
Norman
K6NPB
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 1:10 PMHad not heard of these, so googled it, and it sure damn does look cool. I'll bet they come way down in price in the coming year or so though. Hope so anyway. Good to know about them. thanks. -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 1:12 PMhi will fyi they can be had for about 320 bux on ebay. -
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Re: trying to run my pocket projecter off 12v
Sun, July 5, 2009 - 1:14 PMyou know if i can lick the power delivery problem this thing is going to be a great low power consuming device for off grid living.
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 5:58 AMIs the AC converter a “switching power supply”? If it is the Projector is probably detecting that it isn't getting continuous power and switching from charge to projector mode. If this is the case about your only option is to convert up to 110 and then use the provided supply.
Of course you could design your own switching supply. The timing will be a bit unusual at 2.4 Hz and even that may not work if the Projector is looking for a different frequency. If this works it may be your best option as there is no power loss due to heat.
USB standards specify that the power supplied is 5v +/- 0.25v at either 100 mA or 500 mA.
I came across a site www.girr.org/mac_stuff/usb_stuff.html , written by an engineer (George Schreyer), that goes into quite a lot of detail and includes a circuit for testing devices. -
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 8:55 AMthe plug reads:
sino american
model: sa110c-05gs-1
switching adaptor
input 100-240 volt
50-60 hz 0.3a
output 5v 2a 10w
so i guess switching?
would hacking a battery work? battery is 3.7 v 1700mah, can i gut one battery, solder wires to the contacts then make some kind of simple circuit board to reduce the voltage from my 12v battery to 3.7v? im thinking the device is picky about everything but the battery so mebe that is the wayto go.
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 9:52 AM -
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 1:49 PMok so this one you mentioned
"www.bixnet.com/uncardcpoadk.html ~~~~ Awesome! "
i ordered because it says its 2a @ 5v and i can also use it to power any laptop to boot so bonus.
if this works i will cook bacon naked!
thanks cookbaconnaked!! -
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 4:38 PMYou still don't know if the projector will work while charging. some gear will not. Will it play from a source input from the USB ? if so you will probably be set to go -
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Re: trying to run my pocket projecter off 12v
Mon, July 6, 2009 - 7:37 PMhi dan,
the projector came with a usb cable for charging only. it shares the same mini usb connector on the rear of the projector that the ac adaptor plugs into. when using the 120v adaptor (plugged into the same mini usb port) the unit charges and plays no problem. when the usb cord has been used (at least so far) it will charge bot the unit will not play, it turns on but the projection bulb does not. -
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Re: trying to run my pocket projecter off 12v
Tue, July 7, 2009 - 5:42 AMIf that is the case , then an external power source may not work, and this would all be a mute question. I would contact the manufacture to get a definitive answer. " can I use an external power source while I'm projecting" ? other wise a charger for your second batter, while using the unit would seem to be your only choice -
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Re: trying to run my pocket projecter off 12v
Tue, July 7, 2009 - 9:06 AMwell dan, china manufacturers are not that easy to get ahold of. i forgot to mention it plays videos from the sd card BUT there is no fast foreward or reverse and one battery lasts 1 hour so you cant finish a movie by battery, only when plugged in. if the 5v @ 2a usb thingie works that would be sweet but if not i will need to build a simple circuit to step 12v down to 3.7v and then hack a battery to accept wires -
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Re: trying to run my pocket projecter off 12v
Tue, July 7, 2009 - 11:57 AMok so i got the power converter with the 5v @ 2a usb slot and tried it, no dice. last up is a battery hack, anyone know how to hack a 3.7v 1700mah lion rechargable battery from a 12v battery? -
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Re: trying to run my pocket projecter off 12v
Wed, July 8, 2009 - 10:01 AMUnless you know *exatcly* what you are doing, do not use LiIon batteries.
Cells (a cell is 3.7V unit, a battery is an array of cells) cannot be used directly but they need some circuitry to avoid full discharge, to avoid fast discharge, to charge the cell properly, to balance load between cells, etc..
See, for example:
www.batteryspace.com/index.asp
And for the charger that accepts 12V as input:
www.batteryspace.com/index.asp
Also, USB is not 5V, but 3.5V (more or less) and the USB connection you have is probably is smarter than you think (I know many cell phones with a dedicated USB charger won't charge from a regular USB port unless you install some driver, the Motorola L2 is one) and it will detect its own power supply.
IMO, your best chance is to use a 12V to 110V converter and use the projector power supply, or if you feel confortable, recycle Computer LiIon cells with the electronics I was suggesting. I have done it for my Roomba....
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Re: trying to run my pocket projecter off 12v
Thu, July 9, 2009 - 1:59 AMWhat do you mean, no dice?
Wrongly pinned?
Not enough Amperage to get it started?
Did you put a volt ohm meter to it to verify it's not a manufacturers defect?
Dude, you're killing me. ;-) -
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Re: trying to run my pocket projecter off 12v
Fri, July 10, 2009 - 4:09 PMok i figured it out, i cut the proprietary mini usb connection off of my 120v supply wire. then i stripped the two wires and read with amp meter, reading 5v so i got 3 male/female 12v jacks and wired them in, two on the power cable from 120v and another to a wire i soldered to a usb cable, i looked up the wiring online but basically red is 5v+ and black is neg-, now this thing plays on any usb source AND i can unplug my custom wire and hook it back up to the stock 110v cable. -
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Re: trying to run my pocket projecter off 12v
Mon, July 13, 2009 - 12:15 PMEUREKA, he's got it!
Very cool.
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