Wired Backward?

DZLHED · 5th June 2007, 23:35

I hear tell KJ wires his sensors backward. I'm thinking this may be why my KJ center section won't talk to my original electronics pod and why my secondary buries the needle in the negative when I try for a voltage reading.

Any comments as to the validity of this assumption and perhaps an explanation as to why it is good to be wired backward would be greatly appreciated.

Todd

Drmike · 6th June 2007, 02:58

Quote: (Originally Posted by DZLHED)

I hear tell KJ wires his sensors backward. I'm thinking this may be why my KJ center section won't talk to my original electronics pod and why my secondary buries the needle in the negative when I try for a voltage reading.

Any comments as to the validity of this assumption and perhaps an explanation as to why it is good to be wired backward would be greatly appreciated.

Todd

Im sure kevin will be along to answer shortly but I believe thats correct. My MK15.5 (SM1600) also has the polarity switched. Using it with my MK16 secondary it reads -1.3

at setpoint 1.3 But I just ignore the -ve

I believe (could be talking bollocks here) that all you have to do is swap the sensor connectors over +ve to +ve, -ve to -ve (ie back to original) to switch polarity - then your original pod and secondary should work.

I know when I used an old MK15 secondary on my (polarity switched)electronics I just had to swap the +ve to -ve connections on the back of the analog display for the needle to go in the right direction.

Hope that helps.

DZLHED · 6th June 2007, 04:12

So... I flip the polarity on my sensors and then swap the polarity to the display in the secondary and all is right with the world?

Man... What ever happened to "ground is ground the whole world round."

Drmike · 6th June 2007, 05:32

Quote: (Originally Posted by DZLHED)

So... I flip the polarity on my sensors and then swap the polarity to the display in the secondary and all is right with the world?

Does the pod work? if so you just need to unsolder the two wires on the back of your analog secondary and swap them over.

If your pod doesnt work then maybe you need to swap over the sensor connectors (in which case you dont need to do anything to your secondary)

....I think

Skipbreather · 6th June 2007, 15:39

Umm… I may be reminding you guys of stuff you already know, but recall:

For reasons known only to God and Biomarine, the original MK15 rev G analog electronics had a + (positive) common!?! The varying signals were carried in the – (negative) branches of the circuitry. Have a look at the old circuit diagrams. It might be that his Dudeness was merely sticking w/ the original strange baseline.

Kevin?

Ken

teksimple · 6th June 2007, 17:29

Yes, it is true. I assume that was because Kevin wanted there to be one Hammerhead version, not two. Of course, this also required Kevin to flip the polarity of my analog secondary to make it work. I did not like re-soldering the sensor leads every time I replace the sensors, so eventually I flipped the sensor lead wires coming off the horseshoe board. Colkan had to make my digital secondary with reverse polarity, which they did at no charge.

DZLHED · 7th June 2007, 03:32

Not sure if he was following suit but my original analog pod and secondary are having a hell of a time with his rebuilt center section...

Not questioning the genius behind it... Just wondering why.

Todd

Quote: (Originally Posted by Skipbreather)

Umm… I may be reminding you guys of stuff you already know, but recall:

For reasons known only to God and Biomarine, the original MK15 rev G analog electronics had a + (positive) common!?! The varying signals were carried in the – (negative) branches of the circuitry. Have a look at the old circuit diagrams. It might be that his Dudeness was merely sticking w/ the original strange baseline.

Kevin?

Ken

heyydude · 7th June 2007, 14:38

Hey everyone,

As Ken said, the original Mark 15 was POSITIVE ground - like my old MGA ("Lucas - the Prince of Darkness" and all that) - I don't exactly know why, nobody else does this, and no electrical engineer has ever given me a good explanation of why they would do that.

Anyway, the Hammerhead is Negative Ground - so all you have to do to use the HH in your Mark 15 is reverse the polarity of your Sensor Leads (or the Leads coming out of your Center Section, and then reverse the Polarity of your Mark 15 Analog Gauge.

As Dr. Mike pointed out, on the Mark 16 Secondary, it just displays a "-" symbol, so you don't need to reverse the polarity there, just ignore the sign.

When I designed the Horseshoe Board, I kept to the Original Layout - that is because we often have customers who just want their Center Section repaired. It seemed to make sense to keep that central part similarly configured to the base units, then change the easily accessible parts (Winchester Connectors, etc.).

Changing the Polarity of the Sensors instead of the Center Section Winchesters made sense when folks used to carry a spare Analog Pod to back up our 1st Gens. As we moved along, the HH Mark 15 proved itself robust enough that most people abandoned that route - therefore, it became easier to just change the Center Section ones.

I'm only on my 1st cup of Coffee, so I hope all this makes sense.

As always, if you have any questions, please feel free to call me at (814) 395-9509 and I'll walk you through the set-up.

All the best,

Kevin Juergensen
Juergensen Marine, Inc.

Dave Sutton · 7th June 2007, 16:04

Quote: (Originally Posted by heyydude)

As we moved along, the HH Mark 15 proved itself robust enough that most people abandoned that route

Maybe.... For those who actually got their rigs back after being sent for upgrade......

Dave Sutton (suffering thru another month of the Mark-15 Hostage Crisis....)

5th June 2007, 23:35	#1 (permalink)
DZLHED Swimmin' upstream Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Join Date: Jun 2005 Location: Maui County, Hawaii Posts: 101	Wired Backward? I hear tell KJ wires his sensors backward. I'm thinking this may be why my KJ center section won't talk to my original electronics pod and why my secondary buries the needle in the negative when I try for a voltage reading. Any comments as to the validity of this assumption and perhaps an explanation as to why it is good to be wired backward would be greatly appreciated. Todd __________________ Aloha, Dieselhead To err is Human... to ccr, Divine. www.NorthShoreExplorers.com
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6th June 2007, 02:58	#2 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,165	Re: Wired Backward? Quote: (Originally Posted by DZLHED) I hear tell KJ wires his sensors backward. I'm thinking this may be why my KJ center section won't talk to my original electronics pod and why my secondary buries the needle in the negative when I try for a voltage reading. Any comments as to the validity of this assumption and perhaps an explanation as to why it is good to be wired backward would be greatly appreciated. Todd Im sure kevin will be along to answer shortly but I believe thats correct. My MK15.5 (SM1600) also has the polarity switched. Using it with my MK16 secondary it reads -1.3 at setpoint 1.3 But I just ignore the -ve I believe (could be talking bollocks here) that all you have to do is swap the sensor connectors over +ve to +ve, -ve to -ve (ie back to original) to switch polarity - then your original pod and secondary should work. I know when I used an old MK15 secondary on my (polarity switched)electronics I just had to swap the +ve to -ve connections on the back of the analog display for the needle to go in the right direction. Hope that helps. __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
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6th June 2007, 04:12	#3 (permalink)
DZLHED Swimmin' upstream Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Join Date: Jun 2005 Location: Maui County, Hawaii Posts: 101	Re: Wired Backward? So... I flip the polarity on my sensors and then swap the polarity to the display in the secondary and all is right with the world? Man... What ever happened to "ground is ground the whole world round." __________________ Aloha, Dieselhead To err is Human... to ccr, Divine. www.NorthShoreExplorers.com
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6th June 2007, 05:32	#4 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,165	Re: Wired Backward? Quote: (Originally Posted by DZLHED) So... I flip the polarity on my sensors and then swap the polarity to the display in the secondary and all is right with the world? Does the pod work? if so you just need to unsolder the two wires on the back of your analog secondary and swap them over. If your pod doesnt work then maybe you need to swap over the sensor connectors (in which case you dont need to do anything to your secondary) ....I think __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
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6th June 2007, 15:39	#5 (permalink)
Skipbreather Reads the fine print Current Rebreather/s: Megalodon Home Build Other Rebreather/s: Not Bought Yet MK 15.X Home Build Join Date: Mar 2005 Location: Chicago, Illinois, USA Posts: 544	Re: Wired Backward? Umm… I may be reminding you guys of stuff you already know, but recall: For reasons known only to God and Biomarine, the original MK15 rev G analog electronics had a + (positive) common!?! The varying signals were carried in the – (negative) branches of the circuitry. Have a look at the old circuit diagrams. It might be that his Dudeness was merely sticking w/ the original strange baseline. Kevin? Ken __________________ "Entropy RULES! Enjoy the interim."
(Online)

6th June 2007, 17:29	#6 (permalink)
teksimple Enlightened Alpinist Current Rebreather/s: Sport Kiss MK 15.X Other Rebreather/s: Sport Kiss Classic Kiss Join Date: Apr 2005 Location: Back in Hawaii Posts: 496	Re: Wired Backward? Yes, it is true. I assume that was because Kevin wanted there to be one Hammerhead version, not two. Of course, this also required Kevin to flip the polarity of my analog secondary to make it work. I did not like re-soldering the sensor leads every time I replace the sensors, so eventually I flipped the sensor lead wires coming off the horseshoe board. Colkan had to make my digital secondary with reverse polarity, which they did at no charge. __________________ ---- _____________ "I don't know the percentage of the Internet that's valid, do you? Jesus, it's scary." - Hunter S. Thompson
(Offline)

7th June 2007, 03:32	#7 (permalink)
DZLHED Swimmin' upstream Current Rebreather/s: MK 15.X Other Rebreather/s: Inspiration Classic Sport Kiss Classic Kiss Join Date: Jun 2005 Location: Maui County, Hawaii Posts: 101	Re: Wired Backward? Not sure if he was following suit but my original analog pod and secondary are having a hell of a time with his rebuilt center section... Not questioning the genius behind it... Just wondering why. Todd Quote: (Originally Posted by Skipbreather) Umm… I may be reminding you guys of stuff you already know, but recall: For reasons known only to God and Biomarine, the original MK15 rev G analog electronics had a + (positive) common!?! The varying signals were carried in the – (negative) branches of the circuitry. Have a look at the old circuit diagrams. It might be that his Dudeness was merely sticking w/ the original strange baseline. Kevin? Ken __________________ Aloha, Dieselhead To err is Human... to ccr, Divine. www.NorthShoreExplorers.com
(Offline)

7th June 2007, 14:38	#8 (permalink)
heyydude King of the Geeks Current Rebreather/s: MK 15.X Optima Other CCR Other Rebreather/s: Other CCR Join Date: May 2005 Location: Addison, Pennsylvania Posts: 340	Re: Wired Backward? Hey everyone, As Ken said, the original Mark 15 was POSITIVE ground - like my old MGA ("Lucas - the Prince of Darkness" and all that) - I don't exactly know why, nobody else does this, and no electrical engineer has ever given me a good explanation of why they would do that. Anyway, the Hammerhead is Negative Ground - so all you have to do to use the HH in your Mark 15 is reverse the polarity of your Sensor Leads (or the Leads coming out of your Center Section, and then reverse the Polarity of your Mark 15 Analog Gauge. As Dr. Mike pointed out, on the Mark 16 Secondary, it just displays a "-" symbol, so you don't need to reverse the polarity there, just ignore the sign. When I designed the Horseshoe Board, I kept to the Original Layout - that is because we often have customers who just want their Center Section repaired. It seemed to make sense to keep that central part similarly configured to the base units, then change the easily accessible parts (Winchester Connectors, etc.). Changing the Polarity of the Sensors instead of the Center Section Winchesters made sense when folks used to carry a spare Analog Pod to back up our 1st Gens. As we moved along, the HH Mark 15 proved itself robust enough that most people abandoned that route - therefore, it became easier to just change the Center Section ones. I'm only on my 1st cup of Coffee, so I hope all this makes sense. As always, if you have any questions, please feel free to call me at (814) 395-9509 and I'll walk you through the set-up. All the best, Kevin Juergensen Juergensen Marine, Inc.
(Offline)

7th June 2007, 16:04	#9 (permalink)
Dave Sutton Membership Cancelled Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Classic Kiss rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,637	Re: Wired Backward? Quote: (Originally Posted by heyydude) As we moved along, the HH Mark 15 proved itself robust enough that most people abandoned that route Maybe.... For those who actually got their rigs back after being sent for upgrade...... Dave Sutton (suffering thru another month of the Mark-15 Hostage Crisis....)
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