powering laser from inverter

[ghosttrain]

Just get a cheap PC UPS. PC UPSs are just that, battery+inverter in a nice package and I think cheaper than buying them separate. Plus they include the electronics which know when to stop charging the battery.

Here's what works with powering lasers (or video projectors) outdoors:
1) PC PSUs. I have a beefy one and no problem powering 1W laser for 4 hours. Though even it says it can't handle more than 900W out. PSUs have batteries and inverters inside them, which leads to option 2
2) Most 12V rechargeable batteries + an inverter which can handle the load. A 10000 mAh battery I tried once powered a 1.4W laser I had for hours.
3) Your car (your cars battery) + inverter
4) Generators which use fuels. These are good for several reasons:
1. no need to waste time recharging
2. no need to worry of battery life, just get enough fuel with you
But have disadvantages too:
1. Are a bit noisy. I tried a Honda one once. If there's music playing, forget about this, not a problem then. if a quiet, more "artistic" or cultural scenario, it might be annoying to the crowd. Maybe go with other options or get a long power cable and move it far enough so the sound won't bother people.
2. They generate a bit of gas. May or may not be an issue for you.

Ideally, if you make your own laser projectors and need to use them outdoor a lot in places with no close power source (for whatever reason), maybe you should put a rechargeable battery inside the projector itself. Think about it, at least for my projectors most stuff inside have a 12V PSU which converts mains power to 12VDC. It seems a waste to convert a 12V DC from a battery to 110/220V AC which is going to be converted to 12V DC inside the projector anyway.

BTW, why is pure sine wave stressed out so much here? I haven't had issues with the cheapest chinese inverters. Don't the AC to DC PSUs inside the projector handle that themselves?

[yoink]

So the pure sine wave isn't so important? Would a 300w inverter be enough for the 300mw laser?

[swamidog]

[QUOTE=yoink; Would a 300w inverter be enough for the 300mw laser?[/QUOTE]

without any specifications on the type and efficiency of your 300mW laser, it's impossible to say. i have a 250mW laser that requires about 1kW to run.

[ghosttrain]

So the pure sine wave isn't so important? Would a 300w inverter be enough for the 300mw laser?

I don't think it is important. Maybe someone can prove me wrong.

There's a difference between the power a device consumes which is measured in Watts and the laser output power which is also measured in Watts.

Even 300mW inverter would "work" with 300mW laser projector, but only if the laser projector consisted only of the laser modules which create the beam and they were 100% efficient which they aren't in real life (meaning it outputs X Watt laser beam by consuming the same X Watts). On top of that laser projectors also have motors (galvos), fans, electronics and other optional components that draw power, so like swamidog said you can't tell how much your lser projector draws power by only knowing the Watts or miliWatts of laser llight it outputs.

The seller knows and you can ask him. It should also be in the manual. If both aren't available, it can be measured with a special device.

[buffo]

Pure sine inverter is not required. Every solid state projector I've ever worked on had a switching power supply(s). They don't know or care from pure sine waves.

If you are experiencing jitter in the scanned image from your inverter, then you have the A/C ground connected to the signal input on your scanner amps, which is a no-no regardless of how you're powering the projector.

I've run a single Pluto II projector (nominal output power 2.5 watts RGB) and a large Dell Laptop (Core2Duo with 17" screen and separate Radeon 5000 series GFX adapter built-in) with an FB3 all on a single 400 watt inverter that I picked up at Harbor Freight for less than $30. (The inverter could handle an 800 watt surge, but 400 watts is the continuous limit.) Used a set of cable clamps to connect the inverter right to the battery on my Jeep. Ran just fine with no jitter in the output at all.

Like Rick said - just run the vehicle now and then to re-charge the battery.

As for how to know what size inverter to buy, you need to measure the amp draw of the projector first, and then use watts law (power in watts = A/C RMS voltage in volts times Current in amps) to figure the power needed. Plutos draw less than 2 amps, so that's less than 240 watts total per projector. Thus a 400 watt inverter is actually more than you need for just one. (The laptop power supply is really low - like 50 watts.)

Adam

[LaserCo]

A pure sine wave inverter allows more "backward compatibility".
-=-
In situations where there are iron core transformers being fed 60hz AC and they need to put out a LOT of current, like for the filament of an argon laser, filament of a microwave ovens's magnetron, a welder etc. You would want to approximate a sine wave for better efficiency.
-=-
Nowdays, in an effort to keep things light weight they have moved away from the big / bulky / heavy iron core transformers towards ferrite cores and even air cores and have raised the frequency above 60hz.
-=-
A sine wave will more closely approximate the signal coming out of a rotary generator, and when you think of it in reverse, will more efficiently power a rotory motor.. (most motors can be generators and most generators can be motors).
-=-
A sine wave is more natural.

[Draco]

what i found that works for me is a boost converter, a laptop top only needs about 18 volts at about 8 amps at full power so i use a Boost converter that takes 12 volts and ups it to 18 volts and that works fine for the computer, for the switch modes in the laser projector i don't believe you need a pure sine wave as the switch mode power supply the projector uses rectifies the 120 volts back into DC before it does it's magic, on the front end of most switchers that i have had experience with they take the ac rectify it into dc filter that with a capacitor and send that to the electronics farther down the line. now i do prefer a true sine wave inverter for my home back up power system and that is mainly to power my furnace and refrigerator and some times a fan, all of which use induction motors, an induction motor will not work correctly with a modified sine wave, they will run slow or even possibly damage the motor. you can also get a laptop power supply that does both ac and dc
This is what i use for my computer in the car http://www.ebay.com/itm/AC-Adapter-P...-/231458429104,
when i lost it in my massive hoard i used a 300 watt boost converter to get the 18 volts but last week i found it behind a file cabinet and has served me very well in my field service roles, i used my laptop as a nav system since i have an older car, but if you need power for your galvos i think you can use two boost converters to get the differential voltage they need with out a more power hungry mains output inverter as long as it's clean dc, you may need to add filtering caps to get rid of the ripple. the cheesy e-bay boost inverter can go to 24 volts and is more effecent in my view, or just use batteries with out the power supply as long as it's the right voltage.
the down side of the iGo was the cost it was over 60 bucks when i got it but does double duty, it works with 120 or 12 volts and comes with different tips for different brands of craptops

for true sine wave inverters i use an APC brand UPS and just added extra batteries for extended run time, i found that the APC true sine wave will run for long amounts of time with out overheating, i cant say the same for other brands though, but even on a scope the ac out was a very clean sine wave, the down side is it's heavy as hell and i went with a rack mount version as they are cheaper on the used market, i have even used them to power circular saws and other power tools, mine can do almost 15 amps and i have a larger one that will do 20 amps, the batteries though are 24 volts and my entire back up power system is 24 volts from the solar panels and batteries. i use them for short outages when dragging the generator out is not needed

[neskusen]

i use an APC brand UPS and just added extra batteries for extended run time

I have a big APC PSU myself (Smart UPS 1500), how do you add extra batteries? There isn't extra spare slots inside so I assume you add them externally somehow?

[Erenozgen]

hi guys. ı want to power my laser with my motocycle battery (7A). The laser company describbed the power of my laser as 35w. Which inverter would work fine with my laser.

[Finale]

35W is pretty low. I'd suggest measuring how much power your laser draws, maybe they meant 350W, not 35. There are cheap AC power meters, you plug the AC plug to one end and plug the meter itself to the wall and it tells the power drawn. Display a white test pattern to know the max power your projector will draw when all diodes are on and scanner is busy at work.