DAKAR SINE WAVE COMBI 12/2500-100 117Vac INVERTER/CHARGER COMBINATION

[Phasma2128]

12vdc to 110vac? 2500 watts? I might be interested. Shipping might be pricey

[Boatsb]

A transformer does not convert DC to AC. It needs to be run through diodes or switches. Don't believe that old is better just because. Progress is good.

[drburke]

Our later Magnum inverter was purchased because of it's options but on an O scope, still produces that saw tooth wave. It does just work for our needs running computers and on board equipment. The remaining UPS units on board still errored on this newer but noisy signal and error out till their batteries die. As common with many later "Just Works" inverters.

Comparing one of these ole Dakars with a later Victron is like comparing a fine ole Rolls with a Mini cooper. Yea, both will get you down the road.

Thanks for this info, Ralph. I plan on getting around it by feeding the inverter output into my isolation transformer thus smoothing it with the existing "big ol' iron" on our boats.

DAN

[Captain Ralph]

Thanks for this info, Ralph. I plan on getting around it by feeding the inverter output into my isolation transformer thus smoothing it with the existing "big ol' iron" on our boats.

DAN

Interesting idea.
I see some extra work in getting the gen-sets to recharge the batteries thru the inverter.
However, just an inverter and the ships own monster charger for the inverter batt bank, and all this could work very well.

Just back up from our Bert. Finally got a working gen-set auto start option on the Magnum. Seems some bugs in previous AGM-n models.
Wow, working sweet now.

[Boatsb]

How does a transformer make a sine wave from DC?

I thought you used diodes, rectifiers and switched power supplies.

Transformers do nothing for frequency. Maybe I need to use larger transformers and see what happens.

I'd never trade the newer units for the old ones. It's nice to have all the great features and controls on the new units.

[jim rosenthal]

Transformers will convert AC to AC- I think the voltage change depends on the turns ratio. They will not change AC to DC, or do anything with DC. Transformers depend on the cyclic enlargement and collapse of electric fields.

[Captain Ralph]

How does a transformer make a sine wave from DC?

I thought you used diodes, rectifiers and switched power supplies.

If you are referring to my text from post #9, maybe I typed to fast or paraphrased poorly.
Transformers help to clean up sinusoidal waves, after they were produced by diodes and rectifiers.
Quality transformers usually weigh more than not so quality transformers.

[Captain Ralph]

Don't believe that old is better just because. Progress is good.

I never said old is better nor progress is not good.
I tried to explain the older units listed in post#1 make a cleaner sinusoidal wave than most newer units and the unit pointed out in post #3.
I also expressed some people that want a very clean AC output wave, consider these and other older models.

[drburke]

Scott, just to clarify (I was not clear), the new units synthesize a sine wave by rapidly switching on and off a DC source.

What Ralph was saying was sometimes there can be residual steps visible in the output which can (but not always) play havoc with some sensitive equipment.

You are right: newer and newer technology does reduce if not eliminate that noise.

We were playing "old school" and considering pushing the slightly choppy sine into a big transformer which serves as an inductive load to force a clean sine wave. So, AC to clean AC.

The disadvantage as Ralph said is keeping around big old hunks of heavy iron, and the advantage is a very clean waveform.

I am on your side: progress is good! Sometimes I trend a little "old school"...

DAN

[Boatsb]

The old units do not use the transformer for creating the sine wave. Its a step up from dc to dc or ac to ac. They use switches and diodes to create the sine wave.

The best way to generate a true sine wave is a dc to ac generator where the dc motor spins the windings. Sheibert and others use this old school method but have moved away from the technology as switching has improved.

A good switing system will surpass the needs of your ac devices easily. With today's power supplies so improved from years gone by the last school products are being replaced.

Also the batteries need to be charged. The old school units don't properly address modern batteries nor do they properly charge and condition the lead acid ones.

So ill go back to my statement that the old inverters are quite inferior to today's quality units.