Power Inverters (Pure Sine?)

**brain21** · 11-02-2004, 02:52 PM

I have a MIPI pc (like a tiny shuttle) that I am going to eventually put in my car. There is no room inside for a power supply (it has an external one). This is going to be placed on the floor in the backseat of the car.

Anyway, it seems like a lot of people here are using regular (modified sine wave) power inverters here. I don't know how much voltage regulation, etc. the stock power supply for my MIPI case offers, and I will also be plugging in a Lilliput 7" once I get one in the next 2 months.

So my question is, why don't I see too many people using Pure Sine inverters rather than Modified Sine inverters? Wouldn't a Pure Since perform much better, and avoid many damaging spike via PWM (Pulse Width Modulation)?

Is it just overkill? I can get a dual AC outlet 150 watt Pure Sine for around $80 and a 300 watt one for around $120 I think.

Thoughts? Comments?

Thanks,

Brain21

**VanMan69** · 11-02-2004, 03:09 PM

I think the main reason people use modified sine is cost. Pure sine is way more expensive, and the advantages are negligible. I haven't seen anyone who's posted a problem with power spikes.

Also, I don't know if they're more or less efficient than modified sine.

**petemillis** · 11-02-2004, 03:28 PM

Pure sine are less efficient that modified sine (modified square actually). I've checked the instructions for my Nikkai 300W modified sine (square) inverter, and it says to check with the equipment manufacturer whether it's ok to power it using modified sine. I guess if the manufacturer says it is, and the inverter then blows it up, you would be able to go back to the inverter manufacturer for comp??

**MatrixPC** · 11-02-2004, 04:07 PM

The cost of a pure sine inverter will cost about the same (maybe little more or less)as the Opus. So people either go with Opus (or other DC-DC route) or the cheaper modified sine wave inverter.