120V Bed Outlet waveform/etc.

Modified square wave isn't necessarily dirty. If the RMS is correct then it's meeting the basic requirements for a functional 120VAC source. You then measure duty cycle, harmonics, phase distortion, peaks & sags to determine how clean it is. This is still true for a quasi-sine wave inverter. For example even a well filtered 3-level single rail PWM can still have significant noise (albeit much improved), particularly at no-load and full load. The only "true" sine wave is a rotating generator, so it's a matter of degrees (mainly cost and control complexity) on any inverter.

No kidding, 860W to 320W is major. Here in Colorado we pay 11.46¢/kW-hr, so that's saving roughly 6¢ per hour.

 

That is my situation as well, it came with my '09 DCSB and in over a year of ownership i have only used it to observe it's performance. At 400/100 watts, and given the abundance of cordless tools and 12 V powered "stuff"it is pretty much useless to me--t'would not be a major flaw in my life if it were not there at all...

 

I wouldn't miss it either. It has proved useful a couple of times when buying and selling stuff on Craigslist, you can demonstrate functionality in any old random parking lot. But that's obviously easily solved with a stand-alone inverter at a much cheaper price.

 

I must say that I am unimpressed with that graph. I don't have a complete electrical background. My background is in physics, naturally learning electronics was something that I had to do alot of. I did mainly DC stuff, very little AC

So is this what an inverter does? Take direct current and "simulate" the sinusoidal nature of alternating current? If so, it would seem to me that's an extremely poor representation of an AC signal. I would imagine more "sensitive equipment" would not care for that type of waveform...

 

Yes, exactly. The approach you take is dictated by how close the AC approximation needs to be and the cost to do so. With enough components you can make an inverter produce an extremely nice AC waveform but at some point (generally as the load requirements become more than a laptop) it quickly becomes more cost effective to just use a generator.

Now that's not always possible, for example solar is a to/from battery system for which tens and hundreds of kW true sine inverters exist to tie them to the grid. But these don't cost $120 either.

Yes, you're right. This approach doesn't yield an especially good AC but it's also not atypical of run-of-the-mill inverters. It can be done very simply and with some care the resulting modified square wave can work. Also, it could be done worse and to do better may not be necessary.

If you use a UPS on your computer this is probably the way the output looks unless it says it's a true sine output. Some converters, like the power brick for your laptop or a USB charger, don't really need a sinusoidal waveform. So for them this is perfectly acceptable as long as you keep the high frequency noise down. Motors and supplies with transformers, however, won't like this at all. You'd never run test equipment or something sensitive on an inverter like this and honestly any inverter is going to need conditioning for truly sensitive work. But even the mains aren't guaranteed to be perfectly clean sinusoidal waveforms either.

The main point here is that Toyota installs what is basically something you'd find for $30 at Walmart. I'm not sure what the individual cost for this would be since it's included as a package, but a name brand 500W true sine inverter is probably $120 or so, which is probably less than the equivalent option cost and is going to shame it on any 'scope.

 

This makes sense. For some of the nucleon detectors I used when working on projects with my professors at Argonne we would use discriminators to keep high frequency noise down for some home-made particle detectors when were conducting basic tests on them. It makes sense that an inverter would do this although it sounds as though the OEM one in the tailgate does not.

This is both surprising to me and not. In my mind Toyota has always tried to give the consumer a quality product for the money, but this inverter (from the data collected so far), is far from quality. At the same time no one in their right mind would use sensitive test equipment using the truck's inverter, so as long as it can run a light or something equivalent reliably the average consumer will be happy.

 

Toyota never claimed the bed inverter was anything special and it's not terrible as far as cheap inverters go (it could be worse, really). Think of it this way, Toyota is not Lexus or Bentley, but rather well made utilitarian vehicles. So it fits that philosophy. I don't know of them burning out or setting fire to trucks and the measurements seem to indicate it's working like you'd expect something of this class to work. It wouldn't surprise me to find it's actually made by someone like Xantrex based on one of their existing designs.

 

I have used my bed socket all of once in the 4 years of ownership of my truck, and it was for a buddies air mattress that only had a 120v hookup on a camping trip. I saved the day, so it did its job exactly as toyota described.

All of my stuff is 12v dc stuffs which makes things much easier and nicer when out in the bush.

 

I also sold my tectronix scope quite a while ago so I can't see exactly what comes out of various ac power generator(s), solar and what not. I tried using the bed socket for a medium sized air pump, didn't work.

 

I just know that common sense has come to the US to die, people are confused they can't run an AC unit on a 100w solar panel, all wire is undersized, nothing if properly fused, people drain their SLA batteries past 50% and expect them to last more than 100 cycles. I just do my best to dummy proof anything I say on the web as I know common sense is rare.

 

Common sense? Whats that? I put in a solar array on my roof this year and I am (most of the time) getting more power than I use out of it.

 

Yeah same here.

 

I just slap a 600W PSW into the trucks. 2012 Tacoma, '05 Tundra, '07 and '08 4Runners. All had the 130A factory alternator. Samlex SSW-600-12A fits under the driver seat. The 130A alternator and a 27F battery can handle it. There's a grommet under the driver seat to run a positive cable from the battery, then ground it to the driver side seat bolt.

 

I need batteries charged, only an AC source can charge them. I need the laptop and cellphone charged, only an AC source can charge them. I like being out in the bush but I also like being in communication.

 

Was there any real surprise that this wasn't a pure sine inverter?

 

We have an ARB fridge in the back of our 4Runner and it stays there most of the time. We have a big Goal Zero yeti plugged into the trucks AC outlet, and the fridge plugged into the 12v outlet on the goal zero. That way we can run the fridge with the truck off and then charge the goal zero when we drive. Works out pretty well and my wife uses the fridge all the time for grocery shopping. Good for when you need to make multiple stops.

 

Can’t contribute much to the technical side of this conversation but can vouch for the usefulness of the inverter. We generally boondock when camping and, on shorter trips, use it with a smart charger to keep our camper’s batteries (two 6V GC2’s wired in series) topped off. The Honda 3K genset goes on longer adventures.

 

I was not surprised when I tested it as I was expecting just a good quality "modified" sine wave (it is better than the el-cheapo I got for $18 at the flea market)--nonetheless I had sort of hoped Toyota would have spent the lousy $100 that a decent quality piddly little 400 W PSW unit would probably have cost them, and put one in...

 

I've had great success with these UPSes below for indoor uses, powering many types of equipment at home (a/v, networking, tech) and work (pbx, network, wifi, hvac controls..) with no problems:
htts://

$240 CyberPower CP1500PFCLCD PFC Sinewave UPS System, 1500VA/1000W, 12 Outlets, AVR, Mini Tower,Black

www.amazon.com/gp/product/B00429N19W
But I've never actually taken a look at the waveform to see how 'true sine wave' it really is, although one Amazon reviewer says it is cleaner than his home's AC and posts a picture of a really clean-looking scope trace.
So, I'm wondering if using something like this UPS in the truck would increase capacity (it says something like 900W nominal max) for short times when the vehicle is turned off or you unplug the UPS so as not to trip the 400W limit on the truck? The max recharge current on this UPS is quite low. Heavy-ish, but not bad for the extra Watts, if you need more than 400W but less than 900W. And you'd have to keep it clean & dry, duh.
Thoughts? Apologies if in any way.

 

The unit's specs state 2 minutes runtime @ 900 watts--that's a lot of hassle for 30 Wh of power.

IMHO the only real solutions for obtaining a usable amount (let's say 1500 W, same as a typical 15 A household receptacle) of 120 VAC in the "wild" are:

1. A 1500 W inverter with some big-ass cables connecting it to a deep cycle 2nd battery;
   
   
2. A small 1500 W ICE (Internal Combustion Engine) powered generator;

Option 1 is obviously more hassle to set up, and would require a larger generator on the truck's engine to even come close to the runtime available via option 2 and a 5-gallon can of gas...