Author Topic: FYI on a Mr Induction portable cooktop and X10 signal strength  (Read 3672 times)

pomonabill22

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FYI on a Mr Induction portable cooktop and X10 signal strength
« on: October 03, 2013, 01:31:09 PM »
I know that ALOT of modern appliances use a micro controller and switching power supplies for efficiency and control.

I recently bought a Mr. Induction 1300watt portable induction cooktop and found a VERY poorly designed input filter.

I reverse engineered the unit because I was measuring a standby power consumption of 25WATTS!!!!  Hardly "green"!

What I found was two 10uF caps across the incoming line!!!  YES that is NOT a typo!!  20 MICROFARADS total cap. across the line!!1 NOT two .01uF but 10 uF!!!!!

Along with being a big signal sucker, I didn't feel like paying for the 25 watts of continuous consumption, so I removed the caps... NOW 0 (zero) watts in standby!

I called the company about the 25 watts, and a chinese lady just giggled and said to unplug it!  WOW is that POOR or what?!?!?!?

Anyway, just wanted to pass this finding on to anyone that might have this particular brand... don't know if other brands are the same or similar.

Brian H

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #1 on: October 03, 2013, 03:14:56 PM »
Are the Chinese capacitors even rated for across power line use?
I would suspect other brands maybe the same. Same factory making all different brand names.

Jeff

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #2 on: October 03, 2013, 03:44:30 PM »
Most electronic components are made in China or Malaysia today.  I was surprised to find the Signal transformers that cost twice as much as Tamura transformers now have a "Made in China" label.  They had been made in Brooklyn, and I understand production was then moved off shore to an island somewhere.

BTW, while big capacitors will certainly kill X10 signals, they will not waste much energy.  The current is out of phase with the voltage, and is "imaginary" power.  A 10uF capacitor would get VERY hot if it was actually consuming that power.

Jeff
X10 automation since the BSR days...

Brian H

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #3 on: October 04, 2013, 02:31:55 AM »
I had another thought.
20 uF sounds big for a simple line filter. Are you sure it was not part of a line conditioning and power regulating circuit?
Yes I know. I am going back in time, to things like a Sola Power Conditioner.
« Last Edit: October 04, 2013, 04:03:46 AM by Brian H »

pomonabill22

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #4 on: October 04, 2013, 11:26:40 AM »
Well I thought it might be there for power factor correction or something a little more exotic, but when I rev. eng. it, it was obvious that there isn't any PFC.
I do remember that when they were there, and after a while they were a little warm although not overly hot.
Here is my crudley hand drawn schematic (partial... power section).
I have a couple of pictures, but the upload limit is small so I can't post good pictures.
The schematic is a pdf and will need to be rotated.
Sorry for the rather confusing drawing... I did this as I traced it out and haven't redrawn it yet.
« Last Edit: October 04, 2013, 11:30:03 AM by pomonabill221 »

pomonabill22

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #5 on: October 04, 2013, 11:37:03 AM »
I had another thought.
20 uF sounds big for a simple line filter. Are you sure it was not part of a line conditioning and power regulating circuit?
Yes I know. I am going back in time, to things like a Sola Power Conditioner.
I kinda thought that might be there for that reason also, but doesn't look like it.

HHMMM... a Sola power conditioner????  Like my Sola Mini/Micro computer power conditioner  Type CVS cat. no. 63-13-150 500VA room heater/boat anchor?

pomonabill22

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #6 on: October 04, 2013, 11:39:34 AM »
Most electronic components are made in China or Malaysia today.  I was surprised to find the Signal transformers that cost twice as much as Tamura transformers now have a "Made in China" label.  They had been made in Brooklyn, and I understand production was then moved off shore to an island somewhere.

BTW, while big capacitors will certainly kill X10 signals, they will not waste much energy.  The current is out of phase with the voltage, and is "imaginary" power.  A 10uF capacitor would get VERY hot if it was actually consuming that power.

Jeff
This is true, but I remember (don't count on my memory though!), I was using a kill-a-watt and had it set on watts (not VA), and that is where I was seeing the 25watts.
I guess the thing to do is reconnect the caps and make sure (NOW that you have me questioning my memory!!!  ;)  )

Jeff

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Re: FYI on a Mr Induction portable cooktop and X10 signal strength
« Reply #7 on: October 04, 2013, 01:44:10 PM »
They are part of a line filter that is preventing the high energy switching circuitry from radiating noise out onto the powerline.  They were probably used to meet FCC regulations on conducted radiation.

And yes, sitting across the AC line like that, they would certainly kill X10 signals.

Jeff
X10 automation since the BSR days...

 

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