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Need help figuring out Chinglesh schematic and a PoE module

HPS USA

May 2, 2017
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Hey guys, I am in a bit of a jam... my customer has supplied a PoE control module with a schematic. I am trying to connect it to a Mag Jack via break-out board. The purpose is to finish the prototype of a power delivery device (battery operated) for PoE (Power over Ethernet).

I am confused by the schematic, and my customer is expecting me to figure this out. I am telling him that the schematic is wrong, he is saying it is not... ;-(

I have attached a photo of the PoE module and the Mag Jack. Also the schematic provided. I have tried to decipher the correct connections, and am afraid I will damage one of my precious samples of the PoE module.

...I need people smarter than me to chime in! Please! ;-)
POE_Module.jpg PoE_Schematic.png
 

Arouse1973

Adam
Dec 18, 2013
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Hello. Which bit do you think is wrong, give me a pointer.
Adam
 

HPS USA

May 2, 2017
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For example, they say that pin #3 is ‘IN+’ and GND and Power Ground...

Also, I am new to PoE and Mag Jacks... I am not an electronics expert by any means.
 

73's de Edd

Aug 21, 2015
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HPS USA . . . .

Isn't this the way that you are interpreting its hookup ?


LAN hookup.jpg

73's de Edd
 

HPS USA

May 2, 2017
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...it might be... lol.

What do you mean by 'Fill in 2-7' ?
 

Arouse1973

Adam
Dec 18, 2013
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It doesn't really matter what voltage you connect to the terminal marked GND, which isn't actually connected to ground. It's all about the potential difference which you need to make sure is within spec. It does seem a little strange what they have done but it will still work if the voltages are within spec.
Adam
 

HPS USA

May 2, 2017
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It doesn't really matter what voltage you connect to the terminal marked GND, which isn't actually connected to ground. It's all about the potential difference which you need to make sure is within spec. It does seem a little strange what they have done but it will still work if the voltages are within spec.
Adam

OK... well I am using a DC\DC step up buck to get to 56VDC, so hopefully that is the correct voltage you refer to...
Also, what is meant by Fill in 2-7'... any idea?

BTW, you guys are great. If I can solve this, my whole weekend just improved. ;-)
 

Arouse1973

Adam
Dec 18, 2013
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Fill in I think is you fill in the rest of the connections. But is not that important so that why he only drew two lines.
Adam
 

Arouse1973

Adam
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Also you need to look at the -V supply which is -45 to -57. This connection needs a minus voltage i.e be lower than GND for this pin.
Adam
 

HPS USA

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Also you need to look at the -V supply which is -45 to -57. This connection needs a minus voltage i.e be lower than GND for this pin.
Adam

Sorry, my ignorance is showing... you are referring to pin #1, yes? And you are saying I cannot simply run the -56vdc from the step up converter?
 

Arouse1973

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If you connect +57 Volts of your power supply to your GND (pin 3) pin and the 0V of your power supply to the Vin pin and measure with a multi-meter across the supply terminals with black connected to GND (pin 3) and the red lead connected to Vin (pin 1) you will read -??V
Adam
 

HPS USA

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If you connect +57 Volts of your power supply to your GND (pin 3) pin and the 0V of your power supply to the Vin pin and measure with a multi-meter across the supply terminals with black connected to GND (pin 3) and the red lead connected to Vin (pin 1) you will read -??V
Adam

Adam, I am sorry... trying to understand what you wrote... I get the +57v to pin3, but what is OV from the power supply?
 

Arouse1973

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Your PSU will have two output connection one red and one black normally. The black one is your 0V.
Adam
 

HPS USA

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Also, as far as filling in connections... the mag jack integrates the transformers... meaning that the PoE module is connecting directly to the soldaer pads shown on the breadboard...
 

Arouse1973

Adam
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Yeah it can be confusing. :) Like the negative of a battery...
 

Arouse1973

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Think of 0V as your return path for the energy you are using in your circuit. There has to be a path to come back to the source that created it in the first place and this path is your 0V i.e. zero energy. After all voltage is energy.
Adam
 

Arouse1973

Adam
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Here is a simple example two voltage sources. One at 500 volts and one at 490 Volts. With an LED and resistor across them. The current in the LED is just under 7 mA. Some people might think the LED will blow up.
Adam

LED_PSU.PNG
 

HPS USA

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Please imagine that the red, black, and yellow lines are physical wires.... is this even close to correct?

Please remember, as far as 'filling in' connections, the mag jack integrates the transformers with the rj45...POE_Module-2.jpg
 

Arouse1973

Adam
Dec 18, 2013
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If your red wire connects to the positive terminal of your power supply then you have them reversed. The more positive terminal of your power supply should connect to the GND connection of that little green PCB.
Adam
 
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