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Discussion Starter · #1 ·
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Hi all
I'm new to the forum. I recently got a bargain generator; It has a briggs I/C 8Hp engine. I'm not sure what the generator head model is.
(see the pics - anybody know) Assuming 90 - 95% efficiency and given that 8hp = 6KW, maybe 4.5KW output ??
Our mains supply here is 220V. The output does give about 220 under load. (I tried a 550W drill and a 2Kw heat gun both together and separately)
The interesting thing is that with no load, I measure a bit over 500vac, this then drops to 220 when loaded.
Even if I plug in a small battery charger without connecting the output, the generator output voltage shows about 217 Vac
I plugged in a mains powered led lamp which works fine.
Is it possible that the unloaded voltage is a 'floating level' which is in fact not likely to supply any significant current?
I assume that the unloaded output is due to the AVR not regulating under no-load conditions.
I tried with another voltmeter, it reads the same - I thought perhaps, I'm getting EMI or spikes which is causing unstable readings.
I had installed one those digital ac voltmeter displays (see the pic). This reads also reads an unstable over-voltage with no load, but shows 217 vac or so as soon as I load.
If I power up the heat gun as well, the voltage goes up slightly to 220V, so I guess the regulator is doing it's thing.
Further questions:
What are the diodes for? Does this give a rectified voltage to drive the avr?
Is the AVR that module with the 4 terminals?
PS - my background is light-current electronics, so I know what I don't know :)
thanks and regards
Russell
 

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well you could preload the generator with an 100 watt light and see what the voltage is.
 

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Discussion Starter · #3 ·
I had a 60W bulb, so I used that. The meter reads 210V and the lamp lights ok. A bit unsteady even when the RPM sounds as though it 's settled.
 

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well that sounds like a plan!
use a 100 watt light to pre load the generator!
 

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Discussion Starter · #5 · (Edited)
That's a dangerous way though. I had a closer look and traced the schematic. (see attached). The large square component with 4 terminals is a bridge rectifier; SKB 30/06A1 (And it's blown - see the picture. Anyone seen a schematic like this one? How does it regulate?
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