Portable 9V power supply

[Fredo]

Hi,


I am looking for a portable 9V DC (300mA) power supply.
For a variety of reasons, we need to record a lot of stuff with the Zoom H4. Unfortunately, the Phantom Power of our 416 sucks the life out of our batteries within 15 minutes. So I am looking for a more robust (and portable) solution.

I know, I know .... don't give me a lecture about doing this kind of stuff with an H4. The matter of fact is that we have to use the H4. My apologies if I can't elaborate about it... Carrying a belt with an additional Power supply shouldn't be a problem, as long as it isn't too heavy and doesn't make too much noise.

Looking forward to your suggestions.

Best regards
Fredo Gevaert
Belgium

[John Willett]

Didn't the H4 have low-voltage phantom? (IE: not the full 48V)?

The 416 only draws 2mA - but it needs 48V + 4V.

[HughH]

Hello Fredo,

I don't know of a portable 9v supply as most of those are 12v or higher for cameras equipment. I suspect the two easiest solutions are to check and see if the H4 will run on 14v (a portable battery on full charge), or regulate a portable battery down to 9v.

It's possible the H4 will run on a higher voltage, but you'd have to test it to find out. The easiest way is to put it on a variable power supply while monitoring the current draw, slowly ramp the voltage up from 9v, and see if the current draw starts to spike.

It's also easy to regulate down to 9v - the LM7809 positive voltage regulator is a chip that will do this. The drawback is you waste the power from the voltage drop to 9v, but it will work. There are switching supplies as well you could wire up but they're more complicated. You could then use a camera battery to deliver your power.

Hugh

[Thomas W. Bethe]

A 12 volt sealed battery and a voltage regulator set to 9 volts DC should do exactly what you need and will run your equipment for a long long time. You can recharge the battery when you are at home base with a standard power supply or battery charger. You can probably build the voltage regulator yourself or find someone with electronic skills to do it for you.

Best of luck!

[Fredo]

Originally Posted by John Willett

Didn't the H4 have low-voltage phantom? (IE: not the full 48V)?

The 416 only draws 2mA - but it needs 48V + 4V.

Just checked the manual and they simply spec 48V & 24V, no extra information.
From the tests we have done so far, it all sounds pretty good, actually better than we expected. What would happen if there's a mis-match?

One other solution might be using a portable Mic preamp, that might kill two birds with one stone.
Any recommendations on that subject, except for the Sound Devices MP or MM1?

Fredo

[Fredo]

Thanks Thomas & Hugh,

I'll ask my maintenance engineer to make me a Voltage regulator.
I hoped for a simple solution, and apparently this is the way to go.

Appreciated.

Fredo

[bishopthomas]

Grace Lunatec