Quick weatherproof camera box.

ahull

634

Re: Quick weatherproof camera box.

« Reply #50 on: 28 / August / 2013, 13:40:26 »

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Quote from: Microfunguy on 28 / August / 2013, 10:31:13

Quote from: ahull on 02 / August / 2013, 18:21:15
I suspect I am going to have more chance with the small tortoise shell butterflies (aglais urticae)

Still masses of Tortoiseshell and Large white, not so many Comma, Red Admiral or Painted Lady, some Common blue and small colony of Silver studded blue (Great Orme, Llandudno).

David

The silver studded blue are a bit exotic for the cooler climate of Scotland, but there are still quite a few of the others you mention. Its been a good summer so far for butterflies, but I still haven't managed to get a picture of the Owls.

I did recently get a few very distant shots of some red kites however.

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ahull

634

Re: Quick weatherproof camera box.

« Reply #51 on: 29 / August / 2013, 05:09:50 »

The second set of figures are in for the Gold solar charger, better than the first, but still pretty poor.
shot:270 04:29 4.09V

I suspect the battery has been allowed to drain <3.0V at some stage in its life, and it is now suffering from reduced capacity, it may recover after a few charge/discharge cycles.. then again it might vent, catch fire, explode, cause a singularity and thus the implosion of the entire planet..

I have left it recharging, sitting on an old dinner plate, next to me, just in case. I presume this will provide sufficient protection, based on the old saying that if you hear the bang, you are OK.

« Last Edit: 29 / August / 2013, 05:12:35 by ahull »

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Microfunguy

4037

Re: Quick weatherproof camera box.

« Reply #52 on: 29 / August / 2013, 06:05:07 »

Quote from: ahull on 29 / August / 2013, 05:09:50

I have left it recharging, sitting on an old dinner plate, next to me, just in case.

Yes, dinner plates are very useful for dealing with singularities.

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ahull

634

Re: Quick weatherproof camera box.

« Reply #53 on: 29 / August / 2013, 12:59:43 »

The dinner plate seems to be holding its own against the unimaginable forces.

BTW If I get a chance I should really post the rest of those butterfly pictures. It might provide a little light relief while I am failing to take pictures of owls.

« Last Edit: 29 / August / 2013, 16:23:48 by ahull »

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ahull

634

Re: Quick weatherproof camera box.

« Reply #54 on: 30 / August / 2013, 04:47:42 »

The third set of figures for the Gold charger are in and they are slowly improving with each charge...

shot:296 04:55 4.09V
shot:287 04:46 4.08V

Still nowhere near the sort of numbers we would expect for a 2600mAh device, but on the plus side, the dinner plate seems to be holding its own, although it did seem to have dragged in some form of alien life when I checked it last night.

I swear you could hear its clogs clatter on the table as it tried to run away.

I know what you are all going to say, I should have used CHDK to do a bit of focus stacking, but there were "voices off" encouraging me stop messing about and get rid of it.

EDIT: ...and if none of that scares you, there's always this... ... or ... this to keep you awake at night while your batteries charge.

« Last Edit: 01 / September / 2013, 07:21:29 by ahull »

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ahull

634

Re: Quick weatherproof camera box.

« Reply #55 on: 02 / September / 2013, 16:13:41 »

I just took a little time to poke around some more in the "Gold Solar Charger (2600mAh)", and have produced an updated picture showing what a lot of the "little black blobs" are, and detailing a few points of interest.

The +5v switching regulator looks to be one of these.

The two larger schottky diodes D1 and D2 marked SS14 look to be these.

Whereas the smaller schottky diode D3 marked S4 from the solar panel looks to be one of these or perhaps these.

The solder pad I thought was probably ground, is. Remember Batt - and Gnd are NOT the same thing in this circuit. Batt - is on the *dangerous* side of the battery protection circuit, and cut and paste in Gimp has given me three schottky diodes misspelt shottky...

moral of the story, always check your work.

I also think that the output from the solar panel may be passed through the 5V regulator to charge the battery, which kind of makes sense, since sufficient ambient light hitting the solar panel, to light the charge LED may only produce as little as 2.9V from the panel, so *something* must boost that high enough to charge the battery (assuming the solar panel actually does anything useful).

This does make for a slightly odd situation, as when no light hits the solar cell, the battery will presumably start to drive the 5V regulator, in effect recharging itself (but in reality simply draining the battery). I will need to dig in to the circuit in a little more detail to see if this is in fact the case. Those two transistors in the bottom corner may be the key to it all.

I think I will test the solar panel output next, probably tomorrow, to see if it does actually charge the battery from flat, and try to make sense of the two transistors in the bottom corner.

Still no sign of the mosfets I ordered, but I do have a shiny new breadboard to do my prototyping on, and the supplier of the "Gold Solar charger" agreed to send a replacement, furthermore my opto-couplers have also arrived, so we look to be making progress.

EDIT: The boards for the mosfets arrived, but still no mosfets. This is the last piece of the switching on the camera puzzle, so hopefully they will be here soon.

« Last Edit: 03 / September / 2013, 04:51:30 by ahull »

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JvdP

174

Re: Quick weatherproof camera box.

« Reply #56 on: 02 / September / 2013, 16:57:26 »

I've looked a bit through your thread and I got interested. Also, I was wondering about a few things.

In some of the cases you write that you want to get the 3.7v straight from the lipo. But as the lipo becomes more empty, the voltage will drop. Although the battery is not yet "empty" it is probably too low of a voltage for the camera.

If you would use 2 lipos in series to get 7.4V then you want to use a DC-DC converter. If I recognised the circuit then that's one of those LM2596. They have probably a 90% efficiency at best. So not optimal.

Have you considered using RC lipo batteries? They are usually of much better quality than those eBay powerbanks and not expensive either. All you need to get in that case is some circuitry to prevent over-discharging and away you go. All-battery.com has these.

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ahull

634

Re: Quick weatherproof camera box.

« Reply #57 on: 02 / September / 2013, 17:45:57 »

Quote from: JvdP on 02 / September / 2013, 16:57:26

I've looked a bit through your thread and I got interested. Also, I was wondering about a few things.

In some of the cases you write that you want to get the 3.7v straight from the lipo. But as the lipo becomes more empty, the voltage will drop. Although the battery is not yet "empty" it is probably too low of a voltage for the camera.

A lot of Canon batteries are 3.7V LiPo batteries, but generally they are smaller and lower capacity than these solar gadgets claim to be, therefore I can run 3.7V based Canon (and other make) camera direct from the LiPo in the solar charger. My idea was to see if I could actually use one of these solar chargers to do very long unattended shoots. Obviously there are easier ways to to this, simply use a big battery and a regulator but I hope to take a different tack. If I can control the battery, and thus the camera, and charge it up faster than it discharges, I can theoretically shoot forever (well for as long as the SD card takes to fill up). This would eliminate the weight and inconvenience of large batteries which are also difficult to recharge in remote locations. Time will tell if I manage this trick or not.

Quote from: JvdP on 02 / September / 2013, 16:57:26

If you would use 2 lipos in series to get 7.4V then you want to use a DC-DC converter. If I recognised the circuit then that's one of those LM2596. They have probably a 90% efficiency at best. So not optimal.

I already do this.

Quote from: JvdP on 02 / September / 2013, 16:57:26

Have you considered using RC lipo batteries? They are usually of much better quality than those eBay powerbanks and not expensive either. All you need to get in that case is some circuitry to prevent over-discharging and away you go. All-battery.com has these.

I previously mentioned here that I was going to use XT60 style RC lipo connectors, this would mean I could use either the solar charger OR an RC lipo and regulator, or both in parallel with a couple of schottky diodes to prevent one charging, or more likely overcharging the other. I intend to design a simple inline mosfet based controller board to allow a PIR or microcontroller to switch their output on and off to the camera.

RC batteries are good, except they too need recharging, and that means visiting the camera to swap them.

« Last Edit: 02 / September / 2013, 18:01:12 by ahull »

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JvdP

174

Re: Quick weatherproof camera box.

« Reply #58 on: 03 / September / 2013, 04:49:33 »

If you go for a microprocessor you might even think of having 2 separate battery circuits which alternate between supplying power to the camera and then being charged by the solar.

How is your experience with using only 1S lipo (3,7v)? Does a fully charged RC lipo not supply too much voltage (usually 4.20v)?

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ahull

634

Re: Quick weatherproof camera box.

« Reply #59 on: 03 / September / 2013, 05:34:02 »

The LiPo cell in these solar chargers is pretty much the same as any other 3.7V LiPo cell, and thus should be interchangeable with the stock camera battery, or a 3.7V RC battery. This would be true for any camera that uses 3.7V LiPo batteries (not just Canon ones), or indeed any other small device that runs on 3.7V, so long as it doesn't draw more current than the battery can safely produce.

Fully charged, the stock Canon battery will be 4.2V (actually more likely 4.1 V approx.) so the camera should be happy with that, in fact some cameras seem happy to run on +5V, but I think this may be pushing your luck slightly. The figure of 4.2V is a function of the LiPo chemistry, not anything unique to Canon. There is some variation between manufacturers as to the maximum charged voltage, but somewhere around 4.1 to 4.2 V is normal. Likewise the minimum allowable discharge voltage varies between manufacturers, but 3.0V is typical.

The DW01 Plus charge protection IC uses the following figures, so our battery will always be within these limits, or else the IC will disconnect it.

Overcharge Release Voltage min=4.05 V typical=4.10 V max=4.15 V

Overdischarge Release Voltage min=2.90 V typical=3.00 V max=3.10 V

Outside of this voltage range "here be dragons", moreover they are probably fire breathing ones.

Note: I have used LiPo and LiIon interchangeably, in this thread though they are slightly different, the basic chemistry is very similar, and their operating characteristics are almost identical.

Basic LiIon cells are usually cylindrical (18650 and similar cells) and LiPo are usually "pouch shaped". "Square" mobile phone and camera styles "batteries" are usually LiPo. Technically these are typically actually single 3.7V cells, rather than batteries of cells.

RC batteries are also usually LiPo, and often multi-cell batteries, often in series and parallel combined pack arrangements to give greater capacity, higher voltage, and/or greater peak current. If the voltage is >3.7V you will need a regulator to avoid releasing the magic smoke. If the battery is 3.7V then so long as you observe the correct polarity, the camera will only draw the current it needs.

If your camera runs on AA or AAA batteries, then it *may* be fine with 3.7V, as two fully charged Alkaline cells will typically give a maximum of 1.65V each (total 3.3V), with two fully charged zinc carbon producing perhaps a little more. Your camera may however object to 4.2V, so you try powering a AA or AAA cell camera this way at your own risk.

« Last Edit: 06 / September / 2013, 11:33:41 by ahull »

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