If the device in question really works at 30VDC, that's a clear sign the diode conduction duty cycle is much longer, and the ratio of peak to average current more benign. You are simulating a circuit with extremely crappy power factor.
After this, the device can't be connected to AC supply and correct DC polarity must be applied. The obvious, and very easy modification is to remove and bypass the bridge rectifier. I know AC rated power supplies are widely used on DC and I do that myself, too, but it's good to know about the potential pitfalls. Depending on package, the highest temperature may not be on the diode case but on one of the legs. For example, run for an hour at the hottest environment you'll ever use it at, use a thermocouple (or a thermal camera) to measure the diode temperature. So the temperature of the diodes is definitely worth monitoring. There may not be a DC rating available at all! So it's obvious for a designer to look at the average current number and choose a suitable part if not generously derated, it's then not suitable for DC. Many integrated diode bridges are not even rated as single diodes but list the maximum average output current assuming sinusoidal AC input. BOM and purchasing is funny, though, sometimes a manufacturer can find a higher rated part for cheaper than a lower rated. Extreme derating rarely takes place in cost optimized mass produced cheap electronics. I don't see why a bridge rectifier would be "highly likely extremely de-rated". Unless the capacitor is really badly undersized. Current spikes from charging from a sinusoidal waveform also are far from "huge". But the good news is that this vac also works with an outlet, so it’s still an option, even if you may or may not be adding other DeWalt tools in the future.Mains 100/120Hz ripple current rarely is problematic to the filter cap anyway capacitors often die in switch mode supplies, but the large cap after the diode bridge seldom is the one dying. If you’re just starting out, however, you’ll need to get the kit that comes with the battery and charger this raises the cost quite a bit and, we think, really compromises the value of this tool. This vac makes the most sense if you already have some other tools in the DeWalt 20-volt line up. The 36-minute runtime really impressed us, though, and it was far longer than that of any other cordless options we tested. There was also the risk of larger items getting caught in the narrow hose. We had no problem sucking up wood shavings, drywall dust, and little bits of this and that, but this vac couldn’t suck up anything heavier, like a nail or a screw. The capabilities of the DeWalt are limited by the small motor and hose diameter. Because there’s also a cordless option and this vac is so light, you won’t have a problem using it in a crawl space, a tight attic, or an outbuilding that needs a little tidying, like a potting shed. But it’s a real champ with little messes around the garage, in the house, or in the basement. This is a much smaller vacuum than the Ridgid models (it doesn’t even have wheels), and it doesn’t match their capabilities on larger areas. If you’re looking for something smaller and more portable, we like the DeWalt DCV581H 20V 2-Gallon Cordless/Corded Wet/Dry Vac. Ridgid gives the vac minor upgrades and tweaks every few years, so the models have changed, but the core positives of the vac have always remained constant. The 12-gallon Ridgid is the vac I saw most on job sites and used the most often throughout a 10-year construction career, and it’s the one I’ve owned at home for years.
And extra filters, hoses, and nozzles are easy to get in an emergency, as long as you have a Home Depot nearby. This Ridgid vac is regularly sold on the shelves of Home Depot (where it has thousands of mostly five-star online reviews). They all store on the vac and out of the way-a smarter design than that of many competitors’ accessory caddies. The Ridgid 12-Gallon NXT Wet/Dry Vac HD1200 comes with two wand extensions and three nozzles (one for general use, another for wet spills, and a small one for detail work). And with its four casters, well-positioned handle, and manageable weight, this model isn’t that difficult to drag through a basement or clunk up a flight of stairs. This wet/dry vac (aka “shop vac” 1) has a large capacity and a powerful motor for sucking up debris.
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