Author Topic: did i break physics?  (Read 16879 times)

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Offline neoTopic starter

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Re: did i break physics?
« Reply #25 on: September 23, 2016, 05:02:14 am »
You think that's bad, you should see his schematics in his other topic|O

They're about as useful as a London Tube map on the Moscow Metro.  :scared:

i will conceed my schematics are terrible but this one doesnt allow me to draw a transformer easily and the other is just really complex
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Offline StillTrying

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Re: did i break physics?
« Reply #26 on: September 23, 2016, 01:04:25 pm »
The best fix would be to delete this whole thread.
.  That took much longer than I thought it would.
 
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Offline Buriedcode

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Re: did i break physics?
« Reply #27 on: September 23, 2016, 04:26:24 pm »
From what I can gather (you haven't made it easy..) you have a mains transformer, the secondary is tapped to give 17V-0V-17V, and you've slapped a 1000uF cap across the two 17V nodes.  So you have 34V RMS across the cap. We have no idea how you measured this, what multimeter setting or anything else involved.  But  if we find the peak... 34 / 0.707 = ~48V peak.  Pretty close to 50V.  How did you test this transformer? 

Even if it was rectified, you still have 34V RMS, which when rectified can easy get to 48V I assumed you rounded up.

I didn't see a rectifier, so that poor cap gets 34V, then -34V across it - did it complain via the standard procedure of exploding and making nasty smells?
 

Offline neoTopic starter

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Re: did i break physics?
« Reply #28 on: September 23, 2016, 05:15:41 pm »
You think that's bad, you should see his schematics in his other topic|O

They're about as useful as a London Tube map on the Moscow Metro.  :scared:

i will conceed my schematics are terrible but this one doesnt allow me to draw a transformer easily and the other is just really complex

You can hand-draw a schematic and then take a picture of that (on macro mode so the camera will focus at a close distance), or scan it if you have a scanner.  WAY faster than drawing a schematic on an eCAD system.  It doesn't need to be pretty-- it just needs to be correct and show the information needed.

For your transformer, is it a dual-primary type [settable to 115V or 230V], a single primary type [only one input voltage]?

Is the secondary only one winding or are there multiple windings?

So, with nothing else connected to the transformer [please disconnect it from everything], what does you meter say is the ACV coming out of the secondary?

Is the transformer connected to a full-wave diode bridge [that info is missing in your schematic]?

Is there anything else connected to the transformer other than line voltage on the input and rectifier on the output?

What is the line voltage in your area [100, 110, 115, 120, or 200, 208, 210, 220, 230, 240, or ???]?

Does the transformer have a label on it that describes the input and output voltages and power (or current) ratings (and what are they)?

Please draw a schematic of what you are doing from line input to the capacitor your showed in your previous schematic, and upload that.  Then, please answer the above questions.  This is the information we need to help you.

-Ken

only one primary 3 secondaries, 17v 2.2v and 1v full wave rectifier yes, and those readings are with nothing else no label 120 mains
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Offline Monkeh

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Re: did i break physics?
« Reply #29 on: September 23, 2016, 06:00:43 pm »
What the f-

That is not how you connect a bridge rectifier.
 

Online PA0PBZ

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Re: did i break physics?
« Reply #30 on: September 23, 2016, 06:07:10 pm »
What the f-

That is not how you connect a bridge rectifier.

Bridge rectifier? Where?

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Offline Monkeh

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Re: did i break physics?
« Reply #31 on: September 23, 2016, 06:07:34 pm »
What the f-

That is not how you connect a bridge rectifier.

Bridge rectifier? Where?



Point.
 

Offline neoTopic starter

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Re: did i break physics?
« Reply #32 on: September 23, 2016, 06:08:31 pm »
sorry
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Online PA0PBZ

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Re: did i break physics?
« Reply #33 on: September 23, 2016, 06:08:52 pm »
I think it is connected right-- it looks like the PDF did not render properly

Well, it looks like GND is connected to the transformer however you render it...
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Offline neoTopic starter

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Re: did i break physics?
« Reply #34 on: September 23, 2016, 06:11:37 pm »
sorry it isnt
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Online PA0PBZ

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Re: did i break physics?
« Reply #35 on: September 23, 2016, 06:11:51 pm »
@neo

Try this:


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Online PA0PBZ

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Re: did i break physics?
« Reply #36 on: September 23, 2016, 06:13:30 pm »
sorry it isnt

Then don't put the label GND there, or is that another PDF failure?
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Offline neoTopic starter

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Re: did i break physics?
« Reply #37 on: September 23, 2016, 06:32:45 pm »
i dont know where my oscilloscope leads are
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Offline Ian.M

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Re: did i break physics?
« Reply #38 on: September 23, 2016, 07:05:45 pm »
Not everyone has access to a scope.  While its careless to mislay the leads (even if some tealeaf has nicked them while your back was turned), we can probably proceed on the basis of meter readings if you have a few simple components to make test jigs e.g  any of 1N4002 up to 1N4007 diode, a 100uF 100V capacitor and a 10K 1/2W resistor.  It would also help if you provide a photo of the hookup of the transformer, rectifier and big capacitor, and also provide the make and model number of your meter so we can check the specs of its AC ranges.
« Last Edit: September 23, 2016, 10:50:45 pm by Ian.M »
 

Offline R005T3r

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Re: did i break physics?
« Reply #39 on: September 23, 2016, 07:06:56 pm »
The transformer you are measuring at the secondary is in a particular modality called "no load", because ideally, a multimeter is a open circuit. Actually that working principle, is very important, because if no load is attached you will have only losses at the primary windings and core losses.
All transformers(and all other motors as well) are made like that in order to compensate the voltage losses when you are working on the "nominal plate" point. every characteristics (especially transformer constants) above or under the nominal point is going to change.

Actually you have this result in any transformer (including the 20KV ones!), but it is way more noticeable on a step down transformer because you work with higher amounts of current than mains ones...
 

Offline Audioguru

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Re: did i break physics?
« Reply #40 on: September 23, 2016, 08:29:57 pm »
I corrected the schematic but I suspect the transformer is 17V-0-17V which is 34V center-tapped to produce a rectified and filtered 44VDC. Then with no load it might measure 50VDC.
 

Offline ZeTeX

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Re: did i break physics?
« Reply #41 on: September 23, 2016, 10:35:05 pm »
neo,
There is a button called "quote", in the right side of the comment.
if you want to reply to someone, click on it and then write your comment, this way we know to which person u are talking to.

can you please take a picture with your phone and upload it here? in the picture we want to see the transformer, the multi-meter that shows 50V and your wiring.
 

Offline pepelevamp

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Re: did i break physics?
« Reply #42 on: September 24, 2016, 02:15:05 pm »
hi guys my alarm went off. did someone break physics?
 

Offline neoTopic starter

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Re: did i break physics?
« Reply #43 on: October 02, 2016, 05:04:03 am »
it was inductance i think anyways i found my oscilloscope probes but before i could thoroughly test it let out a gigantic spark and went down to 24 volts permanently
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Offline StillTrying

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Re: did i break physics?
« Reply #44 on: October 04, 2016, 08:31:36 pm »
it let out a gigantic spark and went down to 24 volts permanently

Probably just yet another PDF, (Potential Difference Flash), - nothing to worry about. :horse:
.  That took much longer than I thought it would.
 

Offline Cyberdragon

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Re: did i break physics?
« Reply #45 on: October 06, 2016, 04:34:51 am »
it let out a gigantic spark and went down to 24 volts permanently

Probably just yet another PDF, (Potential Difference Flash), - nothing to worry about. :horse:

Like this?


EDIT: Your secondary had half of it shorted thus doubling the voltage. The fault burned away so it works now. However the insulation is probably screwed so it may short again or burn out entirely.
« Last Edit: October 06, 2016, 04:41:41 am by Cyberdragon »
*BZZZZZZAAAAAP*
Voltamort strikes again!
Explodingus - someone who frequently causes accidental explosions
 

Offline neoTopic starter

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Re: did i break physics?
« Reply #46 on: October 06, 2016, 05:29:12 am »
kynar insulation doesnt burn as far as i know, not easily at any rate
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 


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