Author Topic: Power measurement issues.  (Read 3782 times)

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Power measurement issues.
« on: April 03, 2010, 23:45:45 pm »
Hi members,


I have a case here. Please try to help me out here.
The story is as follows.
I got an energymeter from Cresta which was tested a Best Buy in a consumertest. This meter was most correct in his measurements.

I put the meter between the 230V wandoutlet and my lab variable powersupply. On this PS are an ampmeter and a voltmeter.

After doing tests with Strait dc and also with a setup with 50% pulses and new coils it was very difficult to say what the powerconsumtion was in these tests.

What i did was keeping the watts on the energymeter on 60watts.
The reading from my PS display where between the 2.5v till 9v and most of the time on 2A.

Question: is the energy meter right because it includes the whole powersupply or should i use the PS readings?

My first impression is to choose for the energy meter.
If thats the right way of measuring then i have good news for you  :D
Strait dc vs 50% duty vs 50% with diodes and coils.....
All tests did 60watts on the energy meter.
The coils setup was a winner....

Steve





« Last Edit: April 04, 2010, 00:03:54 am by Steve »

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Re: Power measurement issues.
« Reply #1 on: April 04, 2010, 11:13:52 am »
Helloooooo....

Do we measure powerconsumption before the powersupply or after?


Thank you.

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Re: Power measurement issues.
« Reply #2 on: April 04, 2010, 16:32:29 pm »
Hey Stevie... I would measure before the power supply.

how about using a small fully charged battery... testing how long it will take to drop to a predetermined voltage. like 10 volts.


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Re: Power measurement issues.
« Reply #3 on: April 04, 2010, 20:50:34 pm »
Hey Stevie... I would measure before the power supply.

how about using a small fully charged battery... testing how long it will take to drop to a predetermined voltage. like 10 volts.

Hi Jolt,

Well, i thought the same. Can you do me a favour and run a test on your PS?
Just measure amps and volts on the 110V, and monitor that when you add some load to the ps. It totally doesnt match here.
The PS pulls like 60watts, but on the PS outlet it does like 10watts.
Seems to me like a lot of losses.

Its pretty hard to explain like this. Can we meet on Skype or msn one of coming days?

Steve


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Re: Power measurement issues.
« Reply #4 on: April 05, 2010, 00:51:05 am »
If it's not a rms meter then you can't believe it to be correct. especially not if your powersource shows more power than your cheap outlet energy meter.

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Re: Power measurement issues.
« Reply #5 on: April 05, 2010, 01:41:39 am »
Hey Stevie... I would measure before the power supply.

how about using a small fully charged battery... testing how long it will take to drop to a predetermined voltage. like 10 volts.

Hi Jolt,

Well, i thought the same. Can you do me a favour and run a test on your PS?
Just measure amps and volts on the 110V, and monitor that when you add some load to the ps. It totally doesnt match here.
The PS pulls like 60watts, but on the PS outlet it does like 10watts.
Seems to me like a lot of losses.

Its pretty hard to explain like this. Can we meet on Skype or msn one of coming days?

Steve

Steve,

I tested mine PS and wow you not kidding those things are so inefficient. I have a 12volt 55 watt automotive bulb and to light it up the PS uses 160 watts. this is horrible!!!!! I think it is because they use an analog method with transistors to control the output voltage.

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Re: Power measurement issues.
« Reply #6 on: April 05, 2010, 10:41:05 am »
Hey Stevie... I would measure before the power supply.

how about using a small fully charged battery... testing how long it will take to drop to a predetermined voltage. like 10 volts.

Hi Jolt,

Well, i thought the same. Can you do me a favour and run a test on your PS?
Just measure amps and volts on the 110V, and monitor that when you add some load to the ps. It totally doesnt match here.
The PS pulls like 60watts, but on the PS outlet it does like 10watts.
Seems to me like a lot of losses.

Its pretty hard to explain like this. Can we meet on Skype or msn one of coming days?

Steve

Steve,

I tested mine PS and wow you not kidding those things are so inefficient. I have a 12volt 55 watt automotive bulb and to light it up the PS uses 160 watts. this is horrible!!!!! I think it is because they use an analog method with transistors to control the output voltage.

I will run a test with my variac and see how that reacts.

Still, with the external powermeter on 60watss, the setup with 2 coils and pulsing at around 15khz showed much more gas then on strait dc.







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Re: Power measurement issues.
« Reply #7 on: April 05, 2010, 16:41:33 pm »
I think you will get a little better efficiency with the variac. maybe 80%

so far the best power supplies are PWM power supplies. like Laptop PSs they are just over 90% efficient.

oh and yeah we can meet on skype.