alternative to the dmw-ac8
- Thread starter Jockomo
- Start date
Ram S.O.S
Well-known member
I bought this AC adapter even before I got the DCC8 coupler, following your link.
Now I got the DC coupler : It was not working for me. The plug of that adapter is not fixed with the DMW_DCC8 at all.
After looking around the house, I found an old AC adapter for portable dvd player, rating as Out Put DC 9V 3A. The plug of this old ac adapter fixed perfectly with the DC coupler. Is it safe to use this adapter?
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Other folks have had good luck with 9V, so you should be OK.
I personally use this adapter on the 8.4V setting, and it works perfectly for me (see my blog post here) -- but at least one person has had a problem with it.
Since it's from Amazon, if it doesn't work for you, you can send it back for a full refund.
Hope this helps,
Bill
Yes, it should work fine.
I think there is a problem generally with using adapters that have max output voltage of only 8.4v. Some work and some don't, there's some variance even of same model of adapter.
I just got the Rhino 2500mA adapter and at 8.4v the camera gives me the message, "This battery cannot be used." I know some other people have successfully used the same model of adapter.
The problem, from what I gather, is that the GH2 battery supplies 8.4v while the GH2 adapter supplies slightly more, around 9v. That way the GH2 can tell whether it's hooked up to battery or ac adapter. When you use an adapter that supplies only 8.4v the camera thinks it's a non-Panasonic battery and refuses to work, so you need to make sure you get an adapter that can supply slightly more than 8.4v.
Someone in another thread (I think person who was making external "power brick" battery solution), speculated that the way the camera distinguishes between battery and adapter is in fact by the voltage level at the terminals.
In any case, I've tried an 8.4v 2500ma adapter and an 8.4 1200ma adapter and both have failed on the GH2, even though they work properly with other devices.
No, for a LI-ion smart battery system, like this one, the interface IC usually determines if a battery is used by sensing a thermistor(the T pin on the batteries).
However, the IC *will* have a UVLO(undervoltage lockout) to prevent using a device that cannot sustain the power(voltage AND current) needed to power the device reliably. In addition to this, most battery interface ICs like this will have the ability to charge the battery as well, which is where the UVLO tends to matter. Unless we can somehow prove otherwise(schematics), I think the main power IC in this unit is a generic Panny battery/charge/multi-output IC and they simply don't use some of the features, like the battery charger portion. So, the UVLO voltage will always be higher than the max battery voltage which is why I think the unit wants a higher voltage from a non-battery source.
However, the IC *will* have a UVLO(undervoltage lockout) to prevent using a device that cannot sustain the power(voltage AND current) needed to power the device reliably. In addition to this, most battery interface ICs like this will have the ability to charge the battery as well, which is where the UVLO tends to matter. Unless we can somehow prove otherwise(schematics), I think the main power IC in this unit is a generic Panny battery/charge/multi-output IC and they simply don't use some of the features, like the battery charger portion. So, the UVLO voltage will always be higher than the max battery voltage which is why I think the unit wants a higher voltage from a non-battery source.
Ram S.O.S
Well-known member
I had the same issue, I bought the Rhino and it didn't work for me. The Adapter in question in this thread is a 9.5v and it works great.
Thanks. And just to be sure: that 9.5v adapter you link to uses the same connector tip as that required by GH2's coupler?
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Thanks, doesn't that fit pretty close with what I was saying? If the voltage is higher than max Panasonic battery voltage the camera assumes it's running off AC power and doesn't check for Panasonic battery compatibility. But if voltage is less than max battery voltage the GH2 assumes it's running off a battery (even when ac adapter is connected) and does a check for proper battery, which it doesn't find if an ac adapter is being used, thus resulting in message, "This battery cannot be used".
The voltage level inconsistencies fit but for a different reason. The IC senses the thermistor in the battery pack and knows it's a battery(also, the battery pack will transmit SBS messages to the IC, such as battery condition/level/charge/discharge, etc). The DC adapter has no thermistor and the unit knows it's NOT a battery and thus it switches to a higher voltage (for the missing battery charging option).
However we don't know this for sure. There also seems to be inconsistencies with the voltage that some cameras fail at too. I think this is a function of current demand from the cameras and the sourcing abilities of the adapters. Not all power supplies can supply fast demands of current from the cameras and will cause voltage droop for a short period of time while the camera boots because the switching power supplies need a small amount of time to "catch up". There are a lot of variables here that need to be taken into account though.
I think I'll make another DC adapter, only this time it will be adjustable and I can see where the cutoff point is.
However we don't know this for sure. There also seems to be inconsistencies with the voltage that some cameras fail at too. I think this is a function of current demand from the cameras and the sourcing abilities of the adapters. Not all power supplies can supply fast demands of current from the cameras and will cause voltage droop for a short period of time while the camera boots because the switching power supplies need a small amount of time to "catch up". There are a lot of variables here that need to be taken into account though.
I think I'll make another DC adapter, only this time it will be adjustable and I can see where the cutoff point is.
Ram S.O.S
Well-known member
Yes indeed it fit's perfect.
Peter J. DeCrescenzo
Veteran
Nah, a _real_ DIY-er would've grown the wood from scratch by planting a seed, tending the sapling, felling the tree, cutting it into boards on their own micro saw-mill, etc.
:grin:
Excellent work, plasmasmp! Whatever it takes!