12V DC to AC power inverter for use inside vehicle - Page 1
Forum section: electronics / general

author: engineheat
author_rank: Frequent Contributor
timestamp: January 15, 2023, 12:19:24 am
content: Hi,I wanted to power an air purifier (120V, 60Hz, 48W) inside the car.I got this inverter from Home Depot:https://www.ryobitools.com/products/details/46396035363#specificationsIt says 120W of "continuous power" and it worked for the few times I tested it, albeit for only a few minutes. Lately there has been a winter storm around Christmas where the temperature dropped very low, and the inverter won't power on. It did power on once when after the interior of the car warmed up, but now it won't power up at all.I'm a novice when it comes to electronics so I wonder if the cold temperature could've ruined the inverter. If so, I'd like to know some possible reasons.I also wonder if the "48W" air purifier drew too much power and possibly burned a fuse inside the inverter?Lastly, the inverter states that it does not produce sinusoidal wave. I wonder if this could have anything to do with it. This last part is the most interesting to me. What is the ramification of powering an AC device via non-sinusoidal wave? For instance, what kind of products is it critical to use a sinusoidal input?I tried searching for Amazon for another inverter and there are many brands I've never heard of. Can you guys recommend a good one for a budget of under $200? I just need to power the air purifier without it dying on me after 2 days. I've heard good things about a brand called Victron.Thanks

author: james_s
author_rank: Super Contributor
timestamp: January 15, 2023, 12:32:24 am
content: It sounds like it's just defective, if it works occasionally I doubt it's the fault of anything you did, it could be a bad solder joint or a bad capacitor, Ryobi is not junk but it's a budget brand that is not fantastic either.Until very recently most inexpensive inverters produce a "modified sine wave" which is actually a square wave with some dead time. Some equipment does not work properly on these, some will even be damaged, but a lot of things work ok. These days pure sine wave inverters are cheap, I got one a few years ago and never looked back. Personally I'd just get one of those, it will work with everything and you don't have to think about it.

author: themadhippy
author_rank: Super Contributor
timestamp: January 15, 2023, 12:51:37 am
content: is this déjà vu revisited?https://www.eevblog.com/forum/chat/12v-dc-to-ac-power-inverter-for-use-inside-vehicle/msg4622776/#msg4622776

author: Psi
author_rank: Super Contributor
timestamp: January 15, 2023, 12:53:20 am
content: yeah, you shouldn't have any issues running a 48W item on a 120W inverter.Does sound like something is wrong either the inverter or the air filter.One thing i would check though, is the cigarette lighter plug on the inverter. And maybe the DCjack end as well.Cigarette lighter connectors are notorious for having bad connections and so that could be the problem.Maybe its just a bad connection and there's a voltage drop that causes the inverter to switch off.Sometimes they get hot and the spring on the tip pin loses all its springyness or they melt a bit.They can also contain a fuse insider the connector, so unscrew the metal bit on the tip and check the fuse looks ok, spring is good and nothing is melted.If you do buy a new one get something with A) a known brand name B) pure sign wave

author: engineheat
author_rank: Frequent Contributor
timestamp: January 15, 2023, 11:34:10 pm
content: Quote from: themadhippy on January 15, 2023, 12:51:37 amYeah, there's a guy who asked me to post it here as I wasn't getting enough help there.

author: engineheat
author_rank: Frequent Contributor
timestamp: January 15, 2023, 11:36:55 pm
content: Quote from: Psi on January 15, 2023, 12:53:20 amCan you recommend one? I want a quality one from a respected brand, not some no-name stuff off Amazon. Thanks

author: engineheat
author_rank: Frequent Contributor
timestamp: January 15, 2023, 11:39:06 pm
content: Quote from: james_s on January 15, 2023, 12:32:24 amCan you recommend a good brand? I tried Amazon but all I see are brands I don't recognize.Thanks

author: sleemanj
author_rank: Super Contributor
timestamp: January 15, 2023, 11:45:35 pm
content: Are you doing your test with the car running? If the car is not running then the battery may be too-low a voltage and your inverter may have a low-voltage cut-off.

author: james_s
author_rank: Super Contributor
timestamp: January 16, 2023, 02:51:47 am
content: Quote from: engineheat on January 15, 2023, 11:39:06 pmThe one I have is made by AIMS Power, it's a 300W continuous model that I think I paid $90 for a few years ago, never had any problems with it.

author: TruslowPJ
author_rank: Contributor
timestamp: February 07, 2023, 05:42:15 pm
content: my personal (cheap) recommendation is the Bestek 300W pure sine wave model. the one with the plastic injection molded case, not the extruded aluminum one.Its ungrounded, and the outputs are isolated, but it puts out pretty clean power, and despite my best (accidental) efforts, refused to die. when I got mine I accidentally fed it 27V DC and its little red light came on but it did not die. it has survived 8 hours at max load powering some incandescent lights as a test, and connecting power supplies with huge inrush currents cause it to go into protect, but again it won't die. it draws about 3/4 of an amp idle, and the fan rarely ever comes on at mild loads. It comes with a cigarette lighter but keep the load under about 100-150w if you are going to plug it into a socket in your car, as usually they are fed with a 15A fuse. my only real complaint about this thing is that it refuses to operate at higher than 15V. that and with the outputs floating, it generates some common mode noise that can cause trackpads on laptops to go haywire according to some reviews.