Photographer needs pro advice...

[klynam]

Greetings to all,

I hope you'll all allow me a little grace in that I am not an engineer. I am a photographer and I need some advice, but this is the only online forum I can find with electrical engineers.

I'm trying to find a portable power source for my strobe lights and don't want to use a generator. I found a Xantrex unit online that I think will suit my needs but I can't afford to buy it and risk blowing it up the first time I use it. It's a small cart containing a sealed rechargeable battery and integrated 1500watt DC to AC inverter. Here's the link:

http://www.xantrex.com/web/id/63/p/1/pt/4/product.asp

The manufacturer specifies up to 1350 watts continuous power (for a limted time of course.) The power-pack that powers my strobes is an 880 watt/second pack that runs on 120v AC at 10amps. According to my calculation (10amps x 120 = 1200 watts) the Xantrex should be able to power this pack.

My questions are:

1. Do photographic strobe power-packs require surges of energy after discharging the strobes (known as recycling in my line of work)? If so, will it exceed the ability of the Xantrex unit to provide power.
2. Assuming the Xantrex can adequately recharge the strobe power-pack, how many times could it recyle the strobe-pack before having to be recharged itself.

I hope this makes sense, and I welcome any advice. If this is not suitable for this forum, I compeletely understand if you must remove my post.

Thank you for your time,

The Image Doctore
theimagedoc@comcast.net

 

[jraef]

"The manufacturer specifies up to 1350 watts continuous power (for a limted time of course.) "

Well there is the issue right there. What is that "limited time"? Batteries are rated in Amp-Hours, so that will be the determinig factor in "how many times". As far as I know, strobe circuits usually have a recharge time limit circuit that will prevent you from firing them off until the capacitors have fully recharged anyway, and that is dependant upon the available voltage. As your power source batteries begin to discharge, their voltage will begin to decay and most likely will result in longer delays between stobe firings, but the total number of firings is totally dependent upon the capacity of the batteries. You should describe your application just as you have above to the manufacturer of the power unit and get an answer from them directly. They are really the only ones that can provide that to you.

"Venditori de oleum-vipera non vigere excordis populi"

 

[KWman]

I would be concerned about the waveform provided by the converter (also called inverter.) Xantrex in the size range below 3000 watt units are often "modified sine wave", which contains a lot of harmonics. In other words, not a pure sine wave. If the load is electronic in nature, as a strobe power system is, there may be heating and/or damage to your strobe from the non-sine wave source power.

I would contact the strobe company to get their recommendation on this point. Ask them if "modified sine wave" or "pure sine wave" source power is required from a source inverter.