A630: DC-in jack for external battery power - Hotwire! Hardware Mods, Accessories and Insights - CHDK Forum
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A630: DC-in jack for external battery power

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Offline Cameratrapcodger

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A630: DC-in jack for external battery power
« on: 07 / May / 2015, 21:59:02 »
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Can someone tell me why I can't get my A630/640s to accept a regulated 4.3 voltage to power the camera using the DC-in jack? I am using a pot to tune a 5v Voltaic regulated 5 v battery to 4.3 v. When there are batteries in the battery compartment the cameras power down the instant I plug it in.  When there are no batteries in the compartment it won't power up using the DC-in connection this way. Obviously the cameras are telling me something.

Is using an external battery wired to proxies the only way to extend battery life in these models?

BTW, the MD script is great for photographing wildlife at night. I use a low level LED video light for illumination, but the NMNH batteries run out in about 4 hours time. I want to get at least 12 hours out of it.   

Suggestions?
« Last Edit: 07 / May / 2015, 22:00:38 by Cameratrapcodger »
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Offline waterwingz

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Re: A630: DC-in jack for external battery power
« Reply #1 on: 07 / May / 2015, 22:20:17 »
Quote from: Cameratrapcodger on 07 / May / 2015, 21:59:02
I am using a pot to tune a 5v Voltaic regulated 5 v battery to 4.3 v.
Please provide a schematic.  If you are simply using the wiper of a pot and setting the voltage by adjusting the pot and measuring wiper to ground "open circuit" then you are going to get a big surprise when the camera turns on and trys to draw upwards of 2 amps (albeit briefly).

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When there are batteries in the battery compartment the cameras power down the instant I plug it in. 
This is normal - inserting the plug into the jack disconnects the batteries.

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When there are no batteries in the compartment it won't power up using the DC-in connection this way.
See my first comments above.


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Is using an external battery wired to proxies the only way to extend battery life in these models?
Proxies ?   You mean so called "fake batteries" machined to the same shape as AA cells but wired to accept external power?

If so , then "no".  That's not the only way to extend camera shooting time.  See my first comment in this post.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline Cameratrapcodger

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Re: A630: DC-in jack for external battery power
« Reply #2 on: 08 / May / 2015, 10:35:09 »
Thank you. Here's the schematic. Yes, fake batteries wired to externals. Glad to hear that's not the only alternative.
« Last Edit: 08 / May / 2015, 10:37:07 by Cameratrapcodger »
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Offline srsa_4c

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Re: A630: DC-in jack for external battery power
« Reply #3 on: 08 / May / 2015, 10:58:24 »
As far as I know the a630 & a640 use 4 AA batteries. That means the camera's internal power supply must be able to deal with 6V, regardless of the voltage of the official external power supply unit. Dropping voltage with a resistor is a very bad idea when powering a device that has a highly variable current draw. A series diode should be sufficient if you're afraid of using the 5V directly.
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Offline waterwingz

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Re: A630: DC-in jack for external battery power
« Reply #4 on: 08 / May / 2015, 14:12:15 »
Quote from: Cameratrapcodger on 08 / May / 2015, 10:35:09
Thank you. Here's the schematic. Yes, fake batteries wired to externals. Glad to hear that's not the only alternative.
Definitely not going to work.   

When you set the pot to the position necessary to get 4.3 volt without the camera connected,  you basically have the wiper set so that there is [ 5K x ( (5.0-4.3)/5) = ] 700 ohms between 5V and the wiper contact.

When you then hookup the camera,  you have 700 ohms in series with the camera.   As soon as the camera tries to draw 1.5 amps (nominal at  startup)  you will get  so much voltage drop across the 700 ohm resistor that there will be nothing left to power the camera and it will either fail to start or immediately shutdown.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline Cameratrapcodger

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Re: A630: DC-in jack for external battery power
« Reply #5 on: 12 / June / 2015, 22:50:06 »
Finally got the A630/640 to run on an external 5v battery (Voltaic #V15) using a USB (A) DC power output cord (OD=4mm, ID=1.7mm). I've gotten between 6.5 and 7.5 hr out of the battery with the camera flash set to 1/3 power (night time shooting). The battery goes out after about 150 exposures. Would like to get more time out of the battery, but am happy for now. Next I will try remote shooting using the USB and a PIR sensor, and expect to get more out of the battery without the LCD being on continuously. 
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