Powering EOS M3/M10 throught night time timelapse situations

udo

Powering EOS M3/M10 throught night time timelapse situations

« on: 19 / February / 2017, 02:50:42 »

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Like I did for the SX260 https://chdk.setepontos.com/index.php?topic=12485.0 I'd like to power the EOS M3 or M10 throughout the night when I get one.
I read about 7.2V batteries, thus being different from S110/SX260.

Questions:
Can I use the 'fake battery' method? Yes ACK-E17 looks very similar.
So what would be the most practical and safe 7.2V source? USB powerbanks only do 5V & 3.7V...
Could I use the powerbank USB output 5V via DCDC step-up converter to 7.2V? E.g. this one? https://benselectronics.nl/lm2577-step-up-boost-/ or perhaps better https://benselectronics.nl/mt3608-step-up-boost-2a-/ ?
What about AC noise (ripple) of the DC converter? See this

for inspiration. Can some filtering with a simple lowpass filter at e.g. 4 Khz fix this? (0,4 uF and 10 ohms)
Or should we consider alternatives?

« Last Edit: 19 / February / 2017, 04:31:19 by udo »

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Ant

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #1 on: 19 / February / 2017, 04:09:45 »

Quote from: udo on 19 / February / 2017, 02:50:42

Can I use the 'fake battery' method?

Yes. Only two contacts needed.

Quote

10 ohms

too much...

« Last Edit: 19 / February / 2017, 04:16:48 by Ant »

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udo

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #2 on: 19 / February / 2017, 04:36:29 »

Quote from: Ant on 19 / February / 2017, 04:09:45

Quote from: udo on 19 / February / 2017, 02:50:42
Can I use the 'fake battery' method?
Yes. Only two contacts needed.

Quote
10 ohms
too much...

Thanks for your response.
So we can choose a boost converter module with higher switching frequency. This moves the noise up in the spectrum and filtering becomes easier.
If we keep the low pass filter @ 4 Khz then we could use 4 uF and 1 ohm resistor.

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Ant

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #3 on: 19 / February / 2017, 07:03:51 »

Quote from: udo on 19 / February / 2017, 04:36:29

If we keep the low pass filter @ 4 Khz then we could use 4 uF and 1 ohm resistor.

I am not sure you need it. There are at least two switching regulators/converters inside the camera. (on main PCB and on sensor PCB). This is not HiEnd audio device - only 14 bit. IMHO it's enough to place 1000+ uF capacitor closer to the battery connector.
Do you think ACK-E17 contain special filters? IMHO it's overpriced switching power supply.

« Last Edit: 19 / February / 2017, 07:16:30 by Ant »

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udo

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #4 on: 19 / February / 2017, 07:15:51 »

Quote from: Ant on 19 / February / 2017, 07:03:51

Quote from: udo on 19 / February / 2017, 04:36:29
If we keep the low pass filter @ 4 Khz then we could use 4 uF and 1 ohm resistor.
I am not sure you need it. There are at least two switching regulators/converters inside the camera. One on main PCB and one on sensor PCB. IMHO it's enough to place 1000+ uF capacitor closer to the battery connector.
Do you think ACK-E17 contain special filters? IMHO it's overpriced switching power supply.

I am not sure about the ACK-E17 and what it contains.
I would like to use the `fake battery` and the cable to the PSU to connect to the DC-DC boost converter and the powerbank.
(very similar to what I did for the SX260: https://chdk.setepontos.com/index.php?topic=12485.msg124202#msg124202)

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c_joerg

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #5 on: 19 / February / 2017, 10:59:52 »

Would really interest me if that would work. I'm thinking about the same problem ...

1) the first problem with Powerbanks is that they turn off at> 2A immediately. My G1x needs at power up approx. 2A at 7.4V (when the lens runs out). This means that at least 3A is required at 5V. Ok, with the M's there is no lens turning out ...

2) rawopint logged the voltage. Comparing the curves made with the battery with those that were made with power supply, you can already see strong ripples. Whether the ultimately effects on the pictures, I always wanted to investigate.

3) I have already experience with this Project:

http://www.dslr-forum.de/showpost.php?p=14417576&postcount=46

I wanted to operate my Flashes Metzt CT45 with a Powerbank. That cost me a lot of sweat.
There are 3 switching regulators in series:
One in the Powerbank, the second to come from 5 to 7.4V and a third in the flash. Depending on the output current, they influence each other. Partial oscillation occur. The flash does not make much problems but how then the camera behaves, you can not say ...

I think about other solutions:
- Transfer the 3.7V from the batterie of the Powerbank directly to 7.4V
- from 2 Powerbanks the 2 * 3.7V in series without switch to come to 7.4V

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M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), S45,
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udo

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #6 on: 19 / February / 2017, 11:20:34 »

Quote from: c_joerg on 19 / February / 2017, 10:59:52

Would really interest me if that would work. I'm thinking about the same problem ...

1) the first problem with Powerbanks is that they turn off at> 2A immediately. My G1x needs at power up approx. 2A at 7.4V (when the lens runs out). This means that at least 3A is required at 5V. Ok, with the M's there is no lens turning out ...

Interesting point. My mi.com powerbank should do 2100mA(TYP) @ DC 5.1V. (see http://www.mi.com/en/pb10000/#params )
Could the M3 or M10 start with those values providing the DC-DC converter with juice? How can we find out?

Quote from: c_joerg on 19 / February / 2017, 10:59:52

2) rawopint logged the voltage. Comparing the curves made with the battery with those that were made with power supply, you can already see strong ripples. Whether the ultimately effects on the pictures, I always wanted to investigate.

What would be good tests? Pictures in black? High shutter speeds?

Quote from: c_joerg on 19 / February / 2017, 10:59:52

I wanted to operate my Flashes Metzt CT45 with a Powerbank. That cost me a lot of sweat.
There are 3 switching regulators in series:

So decent filtering is something we would want.

Quote from: c_joerg on 19 / February / 2017, 10:59:52

I think about other solutions:
- Transfer the 3.7V from the batterie of the Powerbank directly to 7.4V
- from 2 Powerbanks the 2 * 3.7V in series without switch to come to 7.4V

I could do the direct transfer of 3.7->7.4V as I already have the connector in place.
This would eliminate one switching regulator and appears as the best bet.
But this option bypasses the proections mentioned at http://www.mi.com/en/pb10400/
Most importantly the output overcurrent.
What would be practical current limits for the four Li-Ion cells used in the powerbank? Most 18650's should do 2C without damage. So four of these in parallel should be OK. ((?) see http://www.candlepowerforums.com/vb/showthread.php?330186-Maximum-current-on-non-protected-18650-s )
Are we sure a 2A boost converter is working OK for this purpose? Or do we need a larger one?

We should hook up an M3 or M10 to a fixed power supply @ 7.4 volts, limited to 2A or perhaps even lower and see what it does when powered up.

« Last Edit: 19 / February / 2017, 11:36:56 by udo »

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c_joerg

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #7 on: 19 / February / 2017, 11:37:31 »

Quote from: udo on 19 / February / 2017, 11:20:34

How can we find out?

Measuring with the fake batterie…

Quote from: udo on 19 / February / 2017, 11:20:34

What would be good tests? Pictures in black? High shutter speeds?

If I find time, I would do the following:
100 shots with external power supply and 100 shoots with internal batterie.
Same exposure for all pictures (fixed ISO100), against a white wall or against a white picture on a monitor.
The I would calculate the mean and Standard deviation of each picture.
I'm not sure if this really has any meaningful power ...

Quote from: udo on 19 / February / 2017, 11:20:34

So decent filtering is something we would want

I tried a lot of filtering stuff…

Quote from: udo on 19 / February / 2017, 11:20:34

What would be practical current limits for the four Li-Ion cells used in the powerbank?

This limit would be not a problem…

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udo

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #8 on: 21 / February / 2017, 10:02:04 »

Quote from: c_joerg on 19 / February / 2017, 11:37:31

Quote from: udo on 19 / February / 2017, 11:20:34
How can we find out?
Measuring with the fake batterie…

Well, I asked Canon Netherlands via their website and they mentioned this detail in a reply:
Our AC-adapter PS700 has an output of 7.4V (2.0A)
So we could get way with the MT3608 module as it could deliver 2A's for us at that voltage. (I did see some videos of smoking MT3608 modules, though)
The MT3608 switches at around 1 MHz so is easy to filter.

What filters and/or buffering do we add?

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c_joerg

Re: Powering EOS M3/M10 throught night time timelapse situations

« Reply #9 on: 21 / February / 2017, 10:25:38 »

Quote from: udo on 21 / February / 2017, 10:02:04

Our AC-adapter PS700 has an output of 7.4V (2.0A)
So we could get way with the MT3608 module as it could deliver 2A's for us at that voltage. (I did see some videos of smoking MT3608 modules, though)

If you want to have 7,4V / 2.0 A you need at 5V more than 3A….

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