1. Home
  2. ⏚ Electrical Engineering
  3. Any experts on DC-AC inverters? I need help please.

Any experts on DC-AC inverters? I need help please.

Hi, My first post in this newsgroup, I have been asking these questions in various laptop/computer and the Dell computer forums but nobody has been able to answer.

I need some advice on using an Inverter with my Dell 9100 Laptop. I have discovered that a modified square wave inverter will damage my laptop power adapter, so I had it replaced with a pure sine wave inverter, it is this model,

formatting link
- here is another link, but again, its the same model..

formatting link
I am using it on my 9100, but I have had my 9100 for 3 months and have only used the inverter heavily for the last 7 days, during these 7 days, the battery life in the laptop has dropped by about 25%, This is really troubling me as it was consistent before this. Do you have any idea why this might be?

I have had the inverter tested and it is outputting a nice sine wave on an oscilliscope in the store I bought it from..

Also, is it normal for inverters to make cyclic humming sounds when used with laptops? Mine seems to make a funny buzzing/humming sound every few seconds, and the dell power supply hums in sync with it. Again, I took it back to the store and they tested 3 other pure sine wave inverters and they all made similar buzzing/humming sounds that seemed to cycle on and off, as if the load was changing every few seconds.

I don't have any prior knowledge on inverters but have researched them a lot on the internet, however I cannot find anyone or anywhere to answer these questions, hopefully someone here can help.

Any advice appreciated.

Thank

Rob

Reply to
Rob
Loading thread data ...

It could be coincidental if the battery's capacity has diminished since you started using the inverter, but if the inverters output is either low or is sufficiently distorted, the voltage output of the laptops adapter could be lower than the full charge voltage needed for the batteries. That cyclic humming Might be the units output overload protection actuating due to interaction with the power adapters inductive transformer, clipping the output pulses (this is not a true sign wave inverter, rather poorly synthesized). I'm really wondering about the quality of the inverter. You can't use a cigarette lighter adapter, if it's in a vehicle? Anyway, I'd look for a better unit with a better (clean) sign wave, if you must have one of these.

Dave M.

Reply to
Dave M.

Reply to
Chris Johnston

X-No-Archive: Yes

The typical laptop A/C adapter is more forgiving of poor power than anything else. It's usually got a range of 100 to 240V A/C because it has a switching power supply that can modify switching speed and duty cycle to accmodate for this wide range.

How did you diagnose or who told you modified squarewave damages the power adapter?

I've used a laptop on a cig lighter plug in 120W inverter and haven't ever had a problem.

Rob wrote:

Reply to
AC/DCdude17

Thanks for the response, are there any brands you could recommend that have a pure clean sine wave??

Thanks again

Reply to
Rob

Yes, I had a previous laptop that ran for years on a mod sinewave inverter, but when I tried the new Dell on it, the power adapter for the new laptop died within a few minutes.

I should clarify, the power supply for this model has two circuits, one for powering the laptop and one for charging it, the charging circuit failed and I could not charge the laptop at all.

So I had the power adapter replaced and bought a pure sine wave adapter and it works ok now except for the humming/buzzing. Incidentally, I emailed the manufacturer and they replied with basically the same explanation as Dave M.

Rob

Reply to
Rob

Yes, I received a reply from the techs at the company who made my inverter and they pretty much said the same thing, they said I needed a higher capacity inverter (same price - clean swap)

I'll try it later this week when I pick it up. Thanks again for the response and I have learned a lot this week! :-)

Reply to
Rob

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.