Aaaargh

[Wombat]

Hey all,

I have a technical problem here!

I have been running my Sanyo radio CD on a little 100w inverter (just read that the system sucks 110 watts!), the inverter is at least modified sine wave and possibly square wave. When I came home tonight the overload on the inverter was tripped (funny 'bout that) but the sound system was dead as a maggot. Investigation seems to infer that the internal transformer is burned out. The stuff I read on the 'net seems to say that modified sine wave should be OK with this sort of gear.

But it is still burned out.

Any thoughts Muddy? Martin? anyone?

Nev

[Muddypause]

Well, I wouldn't want you to get the idea that I know anything about electronics (or indeed anything else), but from what I think I do know, a sine wave is A Good Thing, and a square wave is A Bad Thing - for some applications, more so than for others. But as you say, for this type of application, a modified sine wave seems to be reckoned OK.

However, a modified sine wave is actually a modified square wave, and I would guess that there may be degrees of modification, some better than others.

On the other hand, transformers do burn out even in the best of circumstances. Some of them are protected by an internal fuse or other type of cut out, which I feel sure you may already have checked.

Is it possible to dispense with both the inverter and the transformer, and run the unit directly from your low voltage supply, maybe with some kind of voltage regulator?

[Martin]

Sounds like you've fried the internal fuse in the transformer, which is often non-replaceable - I'd concur with Muddy that you'd be far better to "run direct" off battery power
Modified squarewave inverters often have this effect, and although sold as being perfect for all "mains" uses are actually highly unsuitable for many - and it's not easy to find out precisely what will run satisfactorily, and what won't......
Some energy saving bulbs work fine, others "buzz" and have a short life - I wouldn't risk any precious circuitry with them. There's two answers - ditch the inverter and spend a little extra for true sinewave, or run direct from the battery voltage (preferable)

[Martin]

I've been experimenting with cheapie switch-mode voltage converters, and they would appear to be an excellent solution - if you have say a 12v battery, and a radio that runs on 4.5 volts, you can use them to drop the voltage from the battery. Look for the magic words "regulated", and "switch mode" - they only cost a few quid, and work well!

[Wombat]

Thanks guys,

I suspected the the sine wave inverter was the way to go. I think that straight run 12 volt is good too but some applications just don't have good quality or powerful stuff in 12 volt.

I had the transformer looked at professionally and they said it was fine.....so I dunno!

Nev