Enough Power in this Inverter?

jasonb

Hi there,

I hope this is the right forum, please let me know if it isn't.

My Dad needs to use a Nebuliser every 4 hours or so. He sometimes finds it awkward to plan his day as he needs to make sure he's somewhere he can plug it in.

It occurred to me that it might be possible to get an adapter to use it in his car using the 12V Socket.

So I looked into it, and lo and behold, Inverters exist for this very purpose.

However, they come in different Watt versions, and my vague memory of Leaving Cert Physics reminded me that I need to make sure it's powerful enough.

So, I checked the Nebuliser, and it says 230V and 0.6A on it. If I'm right, that means 138 Watts, correct?

I then looked at some Inverters, and some of the 150W ones actually do 150W for 5 mins, but 120W over a longer period. My Dad needs to use it for about 15-20 mins.

I did find this one:

http://www.ringautomotive.com/uk/products/Cars/In-car+Power/Compact+Inverters/RINVC150

which is 150W, and when I downloaded the manual, it has the following in it:

Max.Continuous power (Watts): 150w (30 mins) 120w (4 hours)

So, what I'm asking is will this do the job, if he needs to get 138W for about 20 mins in his car? I presume it will from the figures, but thought I'd check.

Thanks...

Inverters on cigarette lighter adapters are the tools of Beelzebub.

Get a true sine one you can hard wire and add an external input fuse.
Yes it will work.

red sean

Sir Liamalot wrote: »

Inverters on cigarette lighter adapters are the tools of Beelzebub.

Get a true sine one you can hard wire and add an external input fuse.
Yes it will work.

+1 on the true sine wave. A lot of electronic devices will burn out on the mod. sine wave, cigar lighter inverters.

The cigarette lighter plug will burn and the mod sine will damage sensitive equipment. These are two completely separate issues.

jasonb

Thanks for your replies...

So, assuming that the nebuliser is 'sensitive electronic equipment', this sounds like it would be a waste of money that could damage it, right?

I only use mod. sine for resistive loads they're pretty filthy in terms of power quality. Inductive loads and medical equipment I would recommend true sine.

jasonb

Cool, thanks. I'll look into Pure Sine Inverters then.

I have read online that you should get one that's 3 times the power of what you need. In other words, if I'm looking at needing 138W, I should get a 500W one. Is that true, or just sales talk? I found one that 150W continuous and 300W max, which sounds good to me but doesn't meet the 'three times' recommendation.

Thanks...

Depends on what you're running. For induction motors 10X might be required. For your purposes 150W will be fine.

MorningStar Suresine is good.
Cotek, Xantrex, Marinco, Victron, make decent ones too.
Anything low frequency and weighty gets my vote.

Actually you probably don't need one. If the appliance you are running has one of these:


You'd be a lot better off just using a DC-DC converter.

jasonb

I'm running out of thanks for you... So, basically, what you're saying is that if it uses its own power transformer (or whatever you call those adapters, then it can handle the 12V DV as long as I use a DC-DC Converter? What exactly is the DC-DC Converter doing, converting the amount of Volts?

Thanks...

Yeah it's a switching voltage converter like the wall wart except source power is 12VDC instead of 230VAC.

Inverters are usually just a waste of power. Most people convert 12VDC to 230VAC back to ~12VDC and waste as much power as the appliance uses in the process.

You just have to find a DC power supply with the same output characteristics as the supplied appliance power supply.