From: Tom Kerekes <tk@...>
Subject: Re: [DynoMotion] Power supply help
To: DynoMotion@yahoogroups.com
Date: Sunday, April 25, 2010, 4:08 PM

 

Hi Jared,

 

To reduce by 4.5X I meant to divide the number by 4.5.  So instead of P=0.9 and I=0.0018 use P=0.2 and i=0.0004.

 

Regarding connecting your power supply:  The first thing is to verify is that it is isolated from ground (floating).  It sounds like you have two 28V supplies connected in series.  This type of arrangement could be used to generate either +28 and -28 by connecting the ground in the middle, or +54 and +28 by connecting the ground to the "Left".   We desire the latter and only will be using the +54V.   So we want to ground the "Left" pin to the KBreak Ground.  However if the center pin is already grounded then this will result in a short circuit on your power supply and possible damage.  This is unlikely but it is better to be safe than sorry.  To be absolutely sure that there are no built in ground connections: with all power off set your voltmeter to "ohms".  Check for continuity between all 3 pins and all grounds (chassis and Kbreak).  No combination should be less than 10K ohms.

 

If there are no existing connections, then it is ok to connect the Left Pin to KBreak ground.  (Always use ground wires and do not rely on return currents passing through the chassis, and besides with a "floating" supply this wouldn't work anyway).

 

Also be sure to remove KBreak JP8 which connects +12V to Supply Input 0.

 

After connecting the ground (and before connecting the "Right" +54V pin to the KBreak Supply Inputs) verify that the "Right" pin is really +54V by placing your voltmeter black probe to KBreak ground and the red probe to the "Right" pin on your power supply.

 

Good luck

TK 

Group: DynoMotion	Message: 323	From: Tom Kerekes	Date: 4/25/2010
Subject: Re: Power supply help

Hi Jared,   I'm not sure why you read continuity (2.5 ohms or less).  You were supposed to make the measurements before connecting any wire from the Power Supply to KBreak.  If you had a wire connected then of course the two would not be isolated and you would read low resistance.   Regardless, it sounds all correct.  If you already grounded the "Left" pin, powered up with no smoke, and see that there is +54V on the "Right" pin relative to KBreak Ground, then it is ok to connect this "Right" pin to the KBreak VSupply input(s).   Again make sure you remove the KBreak JP8 jumper, otherwise the +12V supply and the +54V supply will be connected together - which would be bad :}   Good luck and thanks for being careful TK Group: DynoMotion Message: 324 From: Jared Tesmer Date: 4/25/2010 Subject: Re: Power supply help As an addition to my other questions is it wrong for me to attach the power supply to ground through my plug. The toroid has 2 red wires for neutral and 2 black wires for hot when run 120v. I used a grounded 120v plug and ran the hot to hot, neutral to neutral and the groung wire I just teminated at the chassis. Will this cause a problem? Will it do anything at all? Thanks Jared --- On Sun, 4/25/10, Jared Tesmer <judrandom@...> wrote: From: Jared Tesmer <judrandom@...> Subject: Re: [DynoMotion] Power supply help To: DynoMotion@yahoogroups.com Date: Sunday, April 25, 2010, 5:33 PM   Tom  When testing the ohms I get no more than 2.5 ohms on anything? Am I testing correctly? When the left pin is connected to k-break ground and the right pin is unconnected I put the black probe on the k-break ground and the red probe on the right pin of power supply an got 54v. I would hate to make a mistake and connect something wrong! Please look at the link I am posting to my power supply and see if that clearsthings up for you as to what i'm working with. http://www.kelingin c.net/SwitchingP owerSupply. html  It is the KL-5413 700w supply at the bottom of the page. Thanks Jared --- On Sun, 4/25/10, Tom Kerekes <tk@dynomotion. com> wrote: From: Tom Kerekes <tk@dynomotion. com> Subject: Re: [DynoMotion] Power supply help To: DynoMotion@yahoogro ups.com Date: Sunday, April 25, 2010, 4:08 PM   Hi Jared,   To reduce by 4.5X I meant to divide the number by 4.5.  So instead of P=0.9 and I=0.0018 use P=0.2 and i=0.0004.   Regarding connecting your power supply:  The first thing is to verify is that it is isolated from ground (floating).  It sounds like you have two 28V supplies connected in series.  This type of arrangement could be used to generate either +28 and -28 by connecting the ground in the middle, or +54 and +28 by connecting the ground to the "Left".   We desire the latter and only will be using the +54V.   So we want to ground the "Left" pin to the KBreak Ground.  However if the center pin is already grounded then this will result in a short circuit on your power supply and possible damage.  This is unlikely but it is better to be safe than sorry.  To be absolutely sure that there are no built in ground connections: with all power off set your voltmeter to "ohms".  Check for continuity between all 3 pins and all grounds (chassis and Kbreak).  No combination should be less than 10K ohms.   If there are no existing connections, then it is ok to connect the Left Pin to KBreak ground.  (Always use ground wires and do not rely on return currents passing through the chassis, and besides with a "floating" supply this wouldn't work anyway).   Also be sure to remove KBreak JP8 which connects +12V to Supply Input 0.   After connecting the ground (and before connecting the "Right" +54V pin to the KBreak Supply Inputs) verify that the "Right" pin is really +54V by placing your voltmeter black probe to KBreak ground and the red probe to the "Right" pin on your power supply.   Good luck TK  Group: DynoMotion Message: 325 From: Tom Kerekes Date: 4/25/2010 Subject: Re: Power supply help I think this is a good idea.  You are earth grounding the power supply chassis when you do this. TK