GH2 GH2 Power - specs, tests, DIY

I know one thing, in a week of reading I learned a lot about batteries and voltage regulators. Yeah
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I know what you mean, I'm trying to make sense of MOSFETs for a DIY intervalometer for 2 days now, and my head is spinning! If anybody knows these, PM me please.
 
g.l said:
As for the 12/9/5V version, don't assume that the outputs will be tightly regulated. I say that as my 12V version (which is also not a multiple of 3.6V) drops from 12.6V->10.8V.
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I didn't assume, I deducted. :-Dum(DBG):

3.6V is the nominal voltage of a Li-ion cell, but a full charged cell will likely have a higher potential, that's why they rate the 12V battery 10.8V (3x3.6V) to 12.6V.

5V and 9V are nowhere close to a multiple of the nominal range. Since the 5V and 9V output capacity (75 Wh and 76.5 Wh respectively) are close, but slightly lower than the 12V capacity (78 Wh), I deduct the 5V and 9V outputs are efficiently regulated.

That battery, if indeed regulated, is a great option, it's self contained, you'd only have to build the plug.
 
Keylight: In your first post you said:

I metered the adapter and it runs at 8.79v. When I connect the Adapter to the camera via my DIY DC adapter, the voltage drops to 8.70. The Amperage is 740mA…

Those figures for current and voltage are way above the specified value of ~3.5 Watts for power draw (8.7 x .74 = 6.4 Watts). Can you measure the current drawn from the adaptor (and the voltage) for three different scenarios (below)? I'd liked to know the current the GH2 actually draws:

1. Screen on default brightness, camera not doing anything.

2. Screen on default brightness, movie being recorded at 24/1080p.

3. Screen off, movie being recorded at 24/1080p.

And if you have an analogue current meter, can you measure the maximum current at switch on? An analogue meter is required (unless you have a peak-reading digital meter), because it has faster response and you can watch the pointer swing upwards.
 
chon said:
I didn't assume, I deducted. :-Dum(DBG):
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You may be right - if you are, it's ideal. Question is:

- is the regulation tight?
- are there any protections (short-circuit, over current, temperature)? The better regulators like the TI have these.
- is 9V safe for the camera / is the 9V output maybe over 9?
- Can you draw from more than one output at the same time?

My instinct on the last one is 'yes, as long as you don't exceed the overall draw rating (whatever it is)'. However I did email an Ebay seller, and he said 'no, strictly one output only, or the battery gets overladed'. I said 'what if you stay inside the overall current rating?' but he insisted. My hunch is he didn't know what he was talking about, but I would double-check.

One final point, if you can build a regulator, then you can buy the cheaper batteries and save money in the long run.
 
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g.l said:
They look almost identical to my batteries, but my seller didn't list a current limit, and the labels on mine or in the picture on your listing don't say anything about current limits. I've emailed my seller, I'll let you know what he says.
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My seller claims 6000ma can be drawn from mine (12V 6800mah). Sounds right (problem is you can never trust people to get technical things right).
 
My seller claims 6000ma can be drawn from mine (12V 6800mah). Sounds right (problem is you can never trust people to get technical things right).
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Could you please post the link of the seller you buy?
I never bought on ebay, I need a good indication someone that send to Brazil.
 
I ordered my PTN78000WAH voltage regulator, it will arrive within 15 days.

I'm thinking of attaching an LED illuminator in the same battery (12v 6800mah) that will make the power of GH2.

I can connect the illuminator directly from the battery without going through the voltage regulator?

This can compromise the quality of energy sent to the GH2 through the voltage regulator?

Technical Specification of LED Illuminator:

Type power cord (6V-17V DC)
Maximum power consumption: Approximately 10W

This is the LED illuminator:

http://lacoloronline.com/product/?CM900-Comer-CM-LBPS900-LED-Light-
 
Eugenio said:
I ordered my PTN78000WAH voltage regulator, it will arrive within 15 days.

I'm thinking of attaching an LED illuminator in the same battery (12v 6800mah) that will make the power of GH2.

I can connect the illuminator directly from the battery without going through the voltage regulator?

This can compromise the quality of energy sent to the GH2 through the voltage regulator?
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1. Connecting the LED light to the battery is fine. Power to the GH2 through the regulator will be okay.

Now let's do some calculations of power:

GH2 … 6.4 Watts (as measured by Keylight, see http://www.dvxuser.com/V6/showthrea...cs-tests-DIY&p=2314614&viewfull=1#post2314614)
Inverter losses (assumed 85% efficient) … 1.0 Watt
LED … 10 Watts

Total = 17.4 Watts.

Battery capacity = 12 x 6.8 = 82 Watt-hrs
Run time = 82/17.4 = 4.7 hours

Throw in another factor of 10% just for the sake of it, and run time = 4.2 hrs. And with a no-name battery, I would expect another 20% drop within a few dozen discharges, to give an estimated, real-life runtime of about ~3 hrs after a bit of use.
 
guyburns said:
1. Connecting the LED light to the battery is fine. Power to the GH2 through the regulator will be okay.

Now let's do some calculations of power:

GH2 … 6.4 Watts (as measured by Keylight, see http://www.dvxuser.com/V6/showthrea...cs-tests-DIY&p=2314614&viewfull=1#post2314614)
Inverter losses (assumed 85% efficient) … 1.0 Watt
LED … 10 Watts

Total = 17.4 Watts.

Battery capacity = 12 x 6.8 = 82 Watt-hrs
Run time = 82/17.4 = 4.7 hours

Throw in another factor of 10% just for the sake of it, and run time = 4.2 hrs. And with a no-name battery, I would expect another 20% drop within a few dozen discharges, to give an estimated, real-life runtime of about ~3 hrs after a bit of use.
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Better to use the LED with a separate battery, it uses Sony batteries, I'll buy two NP-770.

My PTN78000WAH regulator is on the way, I gave it a read the manual and I was scared with the amount of information.

I will seek a professional with enough experience, do not want anything goes wrong.

It is very complex to configure PTN78000WAH to work with a 12V input and output of 8.6 v? Even for those who have a good grasp of electronics?
 
No, it should not be complex for someone who knows what they are doing, and tests the unit after construction. The circuit diagram is on page 1 of the PDF. Only three additional components are required. I don't know where you will mount them.

C1
A 2.2 microfarad , 25 volt, multilayer ceramic capacitor, as described on page 13 and Table 5 on page 15. It's a surface mount device (a pain to use) and cost about 20 cents. This is a tricky component to get hold of. I've never had to use one and hobbyist shops probably don't sell it. Here is what C1 will look like: http://australia.rs-online.com/web/...au:N)&N=4294569320 4294635860+4294635735&No=0

C2
A 100 microfarad, 16 volts electrolytic capacitor. Commonly available.

R(set)
A 1%, 1/2 or 1/4 Watt resistor whose value can be calculated from formula (1) on page 10. I worked it out as 4.3 kohms. Luckily this a standard value in the 1% range. You can calculate the output voltage from this formula, but rearrrange (1) yourself to make sure this is correct:

V = (82.1 + 2.5R)/(6.49 + R) = 8.61

Instead of cluttering up this thread with electronic questions, gmail me at gdburns. I'd like to know how you get on.
 
So my mission now is to find these components to configure the voltage regulator to an output of 8.6 v / 1.5 A. - Knowing that the input is 12V

I ask for help with parts list and if possible a link to where I can buy them.

I'll send you an email guyburns, I'm counting on your help.


I think the list of required components should be part of this topic, it will be useful to others interested in the configuration of voltage regulator PTN78000WAH.
 
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Svart said:
wow, you guys are making things much harder than they need to be.

12v 2A wall wart.
LM317 adjustable regulator
a couple caps, a couple resistors and a pot.

Voila, an adjustable 1.5A regulator where you can dial in your own voltage.

http://www.national.com/mpf/LM/LM317.html#Overview
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This option works the same way that PTN78000WAH?

Can I put any type of 12v battery and with over 6000mAh?


This alternative is as functional and safe as PTN78000WAH?

I really liked the arquiterura PTN78000WAH, his size is pretty nice
 
no, what I suggested is a .50$ adjustable linear regulator. It is not a switching regulator.

You won't have to filter excessively to get rid of the hash that the switching regulator that you want to use will have on it's outputs.

The LM317 is 10mm x 16mm so it's smaller than your PTN78000WAH which is 13mm x 19mm.

What I'm trying to say is that there is just no good reason to use a 20$ switcher where a .50$ linear will do.
 
So I could have saved a lot in this adaptation, now it's late, the PTN78000WAH cost me almost $ 60 with shipping and taxes included. = (

I have read and have the manual, but if someone could list here in this thread the name of the parts with the correct references for setting the regulator to enter 12v and hang out with v 8.6, will be of great value.

Help
 
The diagram on the page I linked you to is the generic adjustable setup for this regulator. Just build it and adjust the output with the camera attached.

So I worked the formula real quick:

The closest you can get with standard resistors is 8.7V with R2=1K43 and R1=240R. With a multi-turn potentiometer you can get closer under load.
 
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