Vector power inverter mods

[ratdude747]

I bought a refurb vector 70W power inverter for $5 yesterday.

tested it, 3 min later and HISS! gray smoke and nasty fumes as well.

no warranty on it (thrift store had buckets of them), so i cracked it , found 2 hot bloated "wisdom" capacitors.

I was able to recap it but it involved modding the plastic case to allow taller caps...

it works now but it is too hot out to see if it is safe to use long term or if i should gut it for parts?

it had a huge heatsink inside... luckily the bolt mount was slotted to allow the bigger caps...

I was using a 65w dell power brick to charge a laptop... it is a 70w moadel so it should have been fine.

they gave an extensive manual with waveforms and lots of techinical info... it said it was not for use with battery chargers, but it said in the next sentence chargers with thier own transformer were ok to use, and to use it for 10 minutes and if the unit was not hot, it was ok for use.

any ideas?

[kc8adu]

Re: Vector power inverter mods

does it contain $5 in scrap?
i have yet to see a good vector product.the switcher overshot and vented the caps.carefull with that thing you will put your laptop out with it!

[ratdude747]

Re: Vector power inverter mods

no returns... i am stuck with it.

staying away then... no way to upgrade the guts in it (and make it safe)?

[smason]

Re: Vector power inverter mods

Most Dell power bricks are SMPSs that are supposed to be good from 100-240v so you're probably safe, but I wouldn't trust it.

[Longbow]

Re: Vector power inverter mods

Remember that the vast majority of inverters produce a square wave output. Many pieces of equipment just don't work well with a square wave input. I would always assume that the "rated" output current is at least 25% overstated. A possible work-around if you must use an inverter is to add filter inductors to the output. The inductors must be rated at the full operating current, and may cost as much as the inverter. The expensive inverters have them built in.

[Th3_uN1Qu3]

Re: Vector power inverter mods

Remember that the vast majority of inverters produce a square wave output. Many pieces of equipment just don't work well with a square wave input.

Agreed. Anything with a SMPS will work (heck, from a SMPS perspective it could as well be straight DC), linear regs will work, but motors may not, and devices with mains transformers will be disturbed by the many harmonics of the square wave.

A possible work-around if you must use an inverter is to add filter inductors to the output.

Which won't do anything by itself on a square wave inverter. You'd also need a capacitor alongside the inductor to form a lowpass filter. And that cap would have to take a ton of ripple too.