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External Power for S100

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Offline waterwingz

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Re: External Power for S100
« Reply #30 on: 06 / December / 2014, 11:07:44 »
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Quote from: srsa_4c on 06 / December / 2014, 08:13:41
Quote from: waterwingz on 05 / December / 2014, 23:24:53
Your SX150 was designed to run from two AA batteries.  Which means that the most voltage it is expecting is 3.0 V.
Canon compacts that run from 2 AA batteries usually have the ACK800 AC adapter as optional accessory. Its rated output voltage is 3.15V, maximum output current is 2A.
The ACK800 plugs into those cameras via a seperate jack - it doesn't use the "dummy battery" method.  As such, the camera may be designed to accept / expect a higher voltage at its power plug?   (And thereby lowering the required current at the same time).   CharlieMAC mentioned  using a dummy battery setup, so his camera would not be seeing more than 3V normally and usually quite a bit lower.

Not sure if all this matters a lot - will all depend on the design tolerance built into the camera I guess.


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If the voltage drop CharlieMAC is experiencing is not due to the power supply, it might be caused by too thin or too long wires. Other cause might be that ATX power supplies need a minimum load on their outputs (+5V, +12V). If the only load is the camera, the regulation won't be optimal and the output voltages won't be within specs.
Good points.

I'm not a big fan of re-purposing ATX type power supplies for other uses.  Adding a dummy load to the +5 might help here -  something like a 2.5 ohm power resistor ( 50 watt).   Or just plug in an old mother board as a dummy load.

And while long, thin wires will cause voltage drop it will tend to be more linear than the series diode(s).  But as always, shorter and heavier gage is better.
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Offline srsa_4c

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Re: External Power for S100
« Reply #31 on: 06 / December / 2014, 11:19:38 »
Quote from: waterwingz on 06 / December / 2014, 11:07:44
The ACK800 plugs into those cameras via a seperate jack - it doesn't use the "dummy battery" method.  As such, the camera may be designed to accept / expect a higher voltage at its power plug?   (And thereby lowering the required current at the same time).   CharlieMAC mentioned  using a dummy battery setup, so his camera would not be seeing more than 3V normally and usually quite a bit lower.
This model no longer has an external power jack, the manual says the following:
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Power Source (...)
  Compact Power Adapter CA-PS800 (included with AC Adapter Kit ACK800)
  • However, the separately sold DC coupler, DR-DC10 is necessary.
So, the official method is to use a battery dummy plus the ACK800.
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Offline CharlieMAC

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Re: External Power for S100
« Reply #32 on: 06 / December / 2014, 14:50:28 »
Thanks for your answers guys. Actually, yesterday I tested the camera with an old ATX power supply supposedly capable of driving 15A on the 3.3V output, but in the real thing, it couldn't even drive the enough current to power the camera up, not even in playback mode. So, getting some thoughts of your responses, I think I will try to add like a dummy resistor on the 5V output.

I'm thinking of designing my own 0-5V voltage regulator using a LM317 or equivalent.

Thanks again!

Best,

Ch.
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Offline waterwingz

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Re: External Power for S100
« Reply #33 on: 06 / December / 2014, 15:34:32 »
Quote from: CharlieMAC on 06 / December / 2014, 14:50:28
Actually, yesterday I tested the camera with an old ATX power supply supposedly capable of driving 15A on the 3.3V output, but in the real thing, it couldn't even drive the enough current to power the camera up, not even in playback mode.
Did you short the necessary pins so that the ATX supply turned on?

http://www.techpowerup.com/articles/other/22
http://www.electronics-tutorials.ws/blog/convert-atx-psu-to-bench-supply.html
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Offline CharlieMAC

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Re: External Power for S100
« Reply #34 on: 06 / December / 2014, 16:47:14 »
Quote from: waterwingz on 06 / December / 2014, 15:34:32
Quote from: CharlieMAC on 06 / December / 2014, 14:50:28
Actually, yesterday I tested the camera with an old ATX power supply supposedly capable of driving 15A on the 3.3V output, but in the real thing, it couldn't even drive the enough current to power the camera up, not even in playback mode.
Did you short the necessary pins so that the ATX supply turned on?

http://www.techpowerup.com/articles/other/22
http://www.electronics-tutorials.ws/blog/convert-atx-psu-to-bench-supply.html

Of course! The fan was actually on :D
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Offline arsenix

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Re: External Power for S100
« Reply #35 on: 07 / April / 2015, 19:25:25 »
Did you every try to power your S100 from 5v? Seems very close to the factory voltage.

I am using A4000 cams with battery eliminators. I currently power them off a very cheap (a few dollars) chinese DC-DC power module that is adjustable. This works but I would rather power them off 5v since there are other components in my system that run off 5.

Anyone ever try 5v? The lithium bats can put out up to 4.2... so 5v isn't far off.
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Offline srsa_4c

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Re: External Power for S100
« Reply #36 on: 08 / April / 2015, 15:55:15 »
Quote from: arsenix on 07 / April / 2015, 19:25:25
Anyone ever try 5v? The lithium bats can put out up to 4.2... so 5v isn't far off.
If you don't know the DC/DC converter chip inside the camera, you can only hope that 5 V (+ noise + inaccuracy) doesn't exceed its specification.

edit:
This source claims that the S100 uses a DC/DC converter named ADP5025. Datasheet is not available. The manufacturer's page does however mention that it accepts input voltages from 2.45V to 5.5V. That means, if your 5V power supply has accurate output voltage, you can probably use it to power the camera directly.
« Last Edit: 09 / April / 2015, 13:48:41 by srsa_4c »
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Offline arsenix

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Re: External Power for S100
« Reply #37 on: 21 / April / 2015, 06:42:23 »
I did confirm that the A4000 uses the MB39C329 power chip, which should take up to 5.5v. So 5v should work for this cam. It seems like most of the canon P&S cams use switching supply chips that can take up to 5.5v, but YMMV!
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