12V to 7.2 power cable at DVinfo.net

Laszlo Horvath · January 16th, 2006, 05:54 PM

I need to power up my HD100 from my portable 12V "power box"
It's a 12V marine battery with 4pin XLR output. I use this "powerbox" with my Sony DSR300a camcorder with success.
I can make a special cable (4pin XLR to mini powerplug which is fit into a "7.2V DC input" of the camcorder, but obviously I need to downconvert the power from 12V to 7.2V
Anybody know who make this cable?
I have a IDX V-mount battery holder, but I want to use this big battery on tripod shoots.

Laszlo

Nate Weaver · January 16th, 2006, 06:09 PM

Quote:

Originally Posted by Laszlo Horvath

I need to power up my HD100 from my portable 12V "power box"
It's a 12V marine battery with 4pin XLR output. I use this "powerbox" with my Sony DSR300a camcorder with success.
I can make a special cable (4pin XLR to mini powerplug which is fit into a "7.2V DC input" of the camcorder, but obviously I need to downconvert the power from 12V to 7.2V
Anybody know who make this cable?
I have a IDX V-mount battery holder, but I want to use this big battery on tripod shoots.

Laszlo

I'm not so sure you have to bump down the voltage. When using the IDX battery adapter on the HD100, I've seen voltages from 12-16v in the finder readout.

I think there's a chance the voltage regulator in the camera has been beefed up for the sole purpose of external batteries. Like my AB adapter seems to step down, but I think the IDX adapter does not.

You should find an IDX adapter and take a meter to it.

John Mitchell · January 16th, 2006, 08:32 PM

Quote:

Originally Posted by Nate Weaver

I'm not so sure you have to bump down the voltage. When using the IDX battery adapter on the HD100, I've seen voltages from 12-16v in the finder readout.

I think there's a chance the voltage regulator in the camera has been beefed up for the sole purpose of external batteries. Like my AB adapter seems to step down, but I think the IDX adapter does not.

You should find an IDX adapter and take a meter to it.

I don't think that's right Nate. The IDX ad in JVC's ProHD propaganda says the IDX solution is a regulated 7.2V. It probably has an intelligent tap telling the camera what voltage the actual battery is sitting at.

Lazlo - you'll need a stepdown transformer capable of carrying the current. I tried a cheapy car adapter rated at 1.5 amps. It powers up the camera head OK but falls over if you try to engage the tape transport so you'll need something beefier than that.

If you do a search I remember reading that someone sourced one from a Canadian camera supplier.

Jiri Bakala · January 16th, 2006, 11:46 PM

The other option would be to get an IDX bracket (like a shell of a battery) that would slide into the IDX adaptor and then you could feed it 12V and the adaptor regulator would take care of the downconversion to 7.2V. Maybe the folks at IDX could help...? Try to buy an old dead IDX battery and gut it.

Steve Mullen · January 17th, 2006, 01:41 AM

Quote:

Originally Posted by John Mitchell

Lazlo - you'll need a stepdown transformer capable of carrying the current.

Since you are dealing with DC and not AC -- an Xformer cannot be used.

Radio Shack may still have or sell its Circuits Handbook that will have a diagram of what you need. I'm in Manila so I can't look it up.

If I remember right you need a Zenar Diode (sp) that rated at the current and voltage you want.

Laszlo Horvath · January 17th, 2006, 09:48 AM

Here:

http://www.swit-battery.com/new/engl...D=200493103759

What you guys think?? If I put this on my IDX adapter - instead of my battery - I thing the IDX adapter will do the job to downconvert the supplied 12V to 7.2V
I'm right??

Laszlo

Mike Teutsch · January 17th, 2006, 10:06 AM

My Varizoom monitor is 12v and the battery for it is 7.2v. It uses a stepping transformer to up the voltage to 12v between the battery and the monitor. Most of these will also work in reverse.

I don't have the time to test it for you as I am leaving for the day now. You can probably get one of these from Varizoom. If you need me to check it, I will be home later this evening.

Good Luck---Mike

Jiri Bakala · January 17th, 2006, 10:23 AM

Quote:

Originally Posted by Mike Teutsch

"The children now love luxury; they have bad manners, contempt for authority; they show disrespect for elders and love chatter in place of exercise. Children are now tyrants, not the servants of their households. They no longer rise when elders enter the room. They contradict their parents, chatter before company, gobble up dainties at the table, cross their legs, and tyrannize their teachers.

Socrates (470 - 399 BC)

How did he know...?
:-)

Steve Mullen · January 17th, 2006, 11:53 PM

Quote:

Originally Posted by Mike Teutsch

It uses a stepping transformer to up the voltage to 12v between the battery and the monitor. Most of these will also work in reverse.

Once again -- transformers can NOT be used with DC. Transformers only work with AC.

A voltage "up-converter" uses the DC to drive a circuit that makes AC which is then fed to a transformer. After the AC voltage is stepped-up, it is rectified back to DC.

Unless the box has been specifically designed to SWITCH between UP and DOWN convert -- the circuit cannot be used in reverse.

So check your box carefully!

Mike Teutsch · January 18th, 2006, 08:10 AM

Quote:

Originally Posted by Steve Mullen

Once again -- transformers can NOT be used with DC. Transformers only work with AC.

A voltage "up-converter" uses the DC to drive a circuit that makes AC which is then fed to a transformer. After the AC voltage is stepped-up, it is rectified back to DC.

Unless the box has been specifically designed to SWITCH between UP and DOWN convert -- the circuit cannot be used in reverse.

So check your box carefully!

Just to satisfy Steve, Varizoom uses a voltage conterter between their AC charging unit and the DC battery.

Part #EC-512, is 12-24v DC input, and 8.4v DC output at 600mA. Perhaps that would work for you.

Mike

Joe Carney · January 18th, 2006, 01:19 PM

You could also try over at www.taperssection.com, those folks deal with kind of stuff all the time. You might even be able to get someone to build it for you for a decent price. They have specific forums on power needs.

Diogo Athouguia · January 19th, 2006, 07:57 PM

Quote:

Originally Posted by Laszlo Horvath

Here:

http://www.swit-battery.com/new/engl...D=200493103759

What you guys think?? If I put this on my IDX adapter - instead of my battery - I thing the IDX adapter will do the job to downconvert the supplied 12V to 7.2V
I'm right??

Laszlo

This is certainly the most secure option. Thanks for the info, now I won't need this JVC charger. I'll get one of those.

Jiri Bakala · January 19th, 2006, 10:22 PM

Quote:

Originally Posted by Laszlo Horvath

Here:

http://www.swit-battery.com/new/engl...D=200493103759

That's what I was talking about...great to know about this option!

Laszlo Horvath · January 19th, 2006, 11:28 PM

Actually guys, I don't thing I was right. If you pay attention, this cable is power out from 12V V-lock battery.
First of all we need male 4 pin XLR NOT female.
Second, if you check the picture very well, the connector going to the bottom of the battery. Ths is not a dummy, this is a real battery, so you can use as a power source if I'm right.
We need something like this, but male 4 pin XLR to special connector (5 pins) to the 12V battery holder. In my case (IDX) five pin connector.
Again, I don't thing this unit is for us.

BTW: I contacted with the owner of Dolgin Enginering and they promised, they do something for me (us?) very soon.

Laszlo

Marc Colemont · January 23rd, 2006, 06:38 AM

I made my own solution:
I bought a IDX adapter, and rebuild it to feed power from my external 12V belt.
Internally in the IDX adapter, there is a DC-DC circuit which converts 12V DC to the 7.2V for the camera. The incoming voltage is routed to the middle pin of the battery socket which is placed on the camera. That explaines why you can see the incoming voltage displayed on the camera viewfinder.
I also added an extra 12V output to feed my Video lamp.
I should have taken pictures while the IDX adapter was open and been modified...

January 16th, 2006, 05:54 PM	#1
Laszlo Horvath Major Player Join Date: Oct 2005 Location: LaSalle Ontario Canada Posts: 289 Images: 5	12V to 7.2 power cable I need to power up my HD100 from my portable 12V "power box" It's a 12V marine battery with 4pin XLR output. I use this "powerbox" with my Sony DSR300a camcorder with success. I can make a special cable (4pin XLR to mini powerplug which is fit into a "7.2V DC input" of the camcorder, but obviously I need to downconvert the power from 12V to 7.2V Anybody know who make this cable? I have a IDX V-mount battery holder, but I want to use this big battery on tripod shoots. Laszlo

January 16th, 2006, 11:46 PM	#4
Jiri Bakala Major Player Join Date: Apr 2004 Location: Kelowna BC Canada Posts: 706	The other option would be to get an IDX bracket (like a shell of a battery) that would slide into the IDX adaptor and then you could feed it 12V and the adaptor regulator would take care of the downconversion to 7.2V. Maybe the folks at IDX could help...? Try to buy an old dead IDX battery and gut it. __________________ www.ascentfilms.com

January 17th, 2006, 09:48 AM	#6
Laszlo Horvath Major Player Join Date: Oct 2005 Location: LaSalle Ontario Canada Posts: 289 Images: 5	I think I find it!!!! Here: http://www.swit-battery.com/new/engl...D=200493103759 What you guys think?? If I put this on my IDX adapter - instead of my battery - I thing the IDX adapter will do the job to downconvert the supplied 12V to 7.2V I'm right?? Laszlo

January 17th, 2006, 10:06 AM	#7
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	Varizoom! My Varizoom monitor is 12v and the battery for it is 7.2v. It uses a stepping transformer to up the voltage to 12v between the battery and the monitor. Most of these will also work in reverse. I don't have the time to test it for you as I am leaving for the day now. You can probably get one of these from Varizoom. If you need me to check it, I will be home later this evening. Good Luck---Mike __________________ Chapter one, line one. The BH.

January 19th, 2006, 11:28 PM	#14
Laszlo Horvath Major Player Join Date: Oct 2005 Location: LaSalle Ontario Canada Posts: 289 Images: 5	Too early to be happy Actually guys, I don't thing I was right. If you pay attention, this cable is power out from 12V V-lock battery. First of all we need male 4 pin XLR NOT female. Second, if you check the picture very well, the connector going to the bottom of the battery. Ths is not a dummy, this is a real battery, so you can use as a power source if I'm right. We need something like this, but male 4 pin XLR to special connector (5 pins) to the 12V battery holder. In my case (IDX) five pin connector. Again, I don't thing this unit is for us. BTW: I contacted with the owner of Dolgin Enginering and they promised, they do something for me (us?) very soon. Laszlo

January 18th, 2006, 01:19 PM	#11
Joe Carney Inner Circle Join Date: Jul 2002 Location: Centreville Va Posts: 1,828	You could also try over at www.taperssection.com, those folks deal with kind of stuff all the time. You might even be able to get someone to build it for you for a decent price. They have specific forums on power needs.

January 23rd, 2006, 06:38 AM	#15
Marc Colemont Major Player Join Date: Nov 2005 Location: Belgium Posts: 695	I made my own solution: I bought a IDX adapter, and rebuild it to feed power from my external 12V belt. Internally in the IDX adapter, there is a DC-DC circuit which converts 12V DC to the 7.2V for the camera. The incoming voltage is routed to the middle pin of the battery socket which is placed on the camera. That explaines why you can see the incoming voltage displayed on the camera viewfinder. I also added an extra 12V output to feed my Video lamp. I should have taken pictures while the IDX adapter was open and been modified... Last edited by Marc Colemont; January 23rd, 2006 at 03:42 PM.