Inverters

normally just an ac motor-generator set , it is simpler to output ac than dc but output quality can be very variable for small cheap units

inverter may be a labelling mistake, some people seem to have learned that 'inverter ' is 'any portable power supply'

or it may be designed to provide a better conditioned output

but output

gah, easy to fall into first-learned mistakes, engine-generator not motor-generator

'inverter '

The real reason is that some small petrol generators are just an engine attached to an alternator. Invertor generators have an engine , an alternator and then a solid state inverter to produce clean AC for todays fussy electronic devices. Hence to differentiate the modern ones from rough old generators the better ones name has been shortened to just inverter.

--
John G.

A large part of the reasoning - apart from a reputed weight saving - is the ability to provide a decent output frequency stability without needing uber-tight engine speed governing.

"Paulie"

** Only modern and generally top of the line ones are.

There is a petrol motor and alternator as usual, but the alternator is three phase and rectified to produce high voltage DC.

This allows the petrol motor to run at any rpm that suits the load conditions - so it is way more fuel efficient.

The DC is converted to 50Hz 240V (or 120V) AC by an inverter, using modern electronics like Mosfets and IGBTs plus of course a uP.

The output frequency and voltage are rock steady and the sine wave quality very good.

.... Phil

Nearly all of todays 'fussy' electronic devices convert whatever input they are supplied with to highly regulated DC, then use that. The source can be almost anything. Typical input range specs I see now are

100-250 volts, for full regulated output. And the frequency is almost irrelevant. Unlike what we used to do in the ancient days, where valve equipment ran off a totally unregulated mains transformer, with just a rectifier and a filter cap.

But I have to agree that 'inverter' for a petrol driven generator is a bit of a misnomer.

--
Regards,

Adrian Jansen           adrianjansen at internode dot on dot net
Note reply address is invalid, convert address above to machine form.

"Adrian Jansen"

** Nothing like true.

A large percentage of items in use today have iron cored transformers - and a large percentage of them use toroidal transformers. The latter are particularly fussy as to the applied voltage and frequency.

And it is not just the ability of the motor to hold a particular rpm ither - both start up and run down can be a real hazard if transformer loads are still connected. If 40 Hz or lower is applied for even a couple of seconds to a toroidal tranny that expects to be fed with 50 Hz, the supply fuse will blow.

** No it is not.

Read the damn thread.

... Phil

are supplied

anything. Typical

the

days, where

rectifier

a

but then the generator is really a motor powered by the engine, and may be an alternator :-)

Haven't taken one apart lately and methods change fast. They may have found it is cheaper to use an inverter from another product line and configure the generator/alternator to feed it DC. Electronics are likely to be much cheaper than materials and mechanicals in the engine or generator.

.

"| || ||| ||||| || |"

** The design is all new.

The alternators use permanent magnets ( neodymium) and are three phase.

The petrol motor is operated over its full speed range.

The end up result is way more run time on a given amount of fuel - especially if lightly loaded.

.... Phil

Not if it is one of those becoming-more-popular type that generate DC and then drive a solid-state inverter to produce the AC.