Hi Nigel;
The issue is when in the wave form the power supply draws all its current. A resistive load draws current relative to voltage so the drawn current trace on a scope follows the voltage wave nearly perfectly, in form. A switched power supply draws current only when the (grid) wave form voltage is in excess of the capacitor storage voltage of the switched power supply, this is a very small portion of the wave form, the current is drawn from the very last part of the rising edge of the wave form.
This isn't a huge problem with a stiff power supply like the national power grid or even a large gen like a Whisper Watt. Running these types of loads on a small gen will severly distort the wave form leaving even less time to charge a capacitive load. This can drive a small gen bananas.
A high quality inverter gen like the Honda I series produces a very very smooth sinewave, usually better than the grid. With it's high frequency rectified pre inverter power supply these gennies can and do deliver large proportional amounts of current into the portion of the waveform where the heavy peak demand of a switching power supply demand current. This preserves the wave form allowing for the proper charging of these very demanding power supplies. A small standard generator can not do this.
An example would be compact flourecent lighting. You can barely run 600 watts worth of these on a 1000 Watt standard gen before many of them loose their mind.
I am not a power expert. I have studied this quite a bit since we use gen power a fair amount. We had a semi with a big 3phase gen and have a stepvan with a Honda 6.5kW gen. We use air compressors, welders, lighting and computers and after having some real issues with switch supply welders and lighting we had to figure out how come we could not power up these "more efficient" peices of equipment. I have had gennies that despite outputting 60 Hz 120 volt metered power, wont charge a laptop or a cell phone.
Not an expert but hope this helps a bit.
All the best,
Barry.
The issue is when in the wave form the power supply draws all its current. A resistive load draws current relative to voltage so the drawn current trace on a scope follows the voltage wave nearly perfectly, in form. A switched power supply draws current only when the (grid) wave form voltage is in excess of the capacitor storage voltage of the switched power supply, this is a very small portion of the wave form, the current is drawn from the very last part of the rising edge of the wave form.
This isn't a huge problem with a stiff power supply like the national power grid or even a large gen like a Whisper Watt. Running these types of loads on a small gen will severly distort the wave form leaving even less time to charge a capacitive load. This can drive a small gen bananas.
A high quality inverter gen like the Honda I series produces a very very smooth sinewave, usually better than the grid. With it's high frequency rectified pre inverter power supply these gennies can and do deliver large proportional amounts of current into the portion of the waveform where the heavy peak demand of a switching power supply demand current. This preserves the wave form allowing for the proper charging of these very demanding power supplies. A small standard generator can not do this.
An example would be compact flourecent lighting. You can barely run 600 watts worth of these on a 1000 Watt standard gen before many of them loose their mind.
I am not a power expert. I have studied this quite a bit since we use gen power a fair amount. We had a semi with a big 3phase gen and have a stepvan with a Honda 6.5kW gen. We use air compressors, welders, lighting and computers and after having some real issues with switch supply welders and lighting we had to figure out how come we could not power up these "more efficient" peices of equipment. I have had gennies that despite outputting 60 Hz 120 volt metered power, wont charge a laptop or a cell phone.
Not an expert but hope this helps a bit.
All the best,
Barry.
While my experiences with cheap generators and audio equipment isn't as bad as that, you can't really expect to run full rated power out of them. Used to run about 1200 watts of audio off of one occasionally, and it took a 5kW gasoline generator to do it. The 2800 watt unit would go nuts every time the bass hit, and would occasionally stall. Even the bigger one would blow up switching supplies - had to limit the power amps to old core-coil transformers.
I eventually said the hell with it and invested in a boatload of 10/3 power cables, once the system got large enough where nothing short of a 20KW diesel would be of any use. If there is a plug or five within 300 feet, I'll plug the darn thing in. If not, there just isn't going to be multi-kilowatt level bass.
I eventually said the hell with it and invested in a boatload of 10/3 power cables, once the system got large enough where nothing short of a 20KW diesel would be of any use. If there is a plug or five within 300 feet, I'll plug the darn thing in. If not, there just isn't going to be multi-kilowatt level bass.
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