The Drek builder's thread

[Magura]

As I expect to need to get rid of a lot of heat, the main heatsink is moved away from the board.



Magura

 

[steenoe]

That's correct.

As I recall, the Drek draws about 500mA

Sure it's gonna be cooking

Magura

The shunty is fine then, having to sink 150mA I know you got the heatsinks for that
500mA through a preamp?? Ya' nutz I better build it into a biggish case, with room for some serious hardware then.



Edit Good call, moving the HS away from the board in this case. I plan to use a series reg at first, and simply measure the excact current draw, before attaching a shuntreg. Luckily I have a spare set of Shunty boards.

 

[Magura]

The shunty is fine then, having to sink 150mA I know you got the heatsinks for that
500mA through a preamp?? Ya' nutz I better build it into a biggish case, with room for some serious hardware then.

500mA is for two channels, I recall specifying 250 or 300mA as minimum current per inductor.



Magura

 

[steenoe]

Morten, how do I find the correct CT point on this one? Is it simply the 2 in the middle?
No prob's finding two windings

 

[Magura]

Morten, how do I find the correct CT point on this one? Is it simply the 2 in the middle?
No prob's finding two windings

As I recall, there are two longer, and two shorted leads. They represent the inner and outer to each coil.


Magura

 

[cviller]

Cool you have turned this old thread back on - and it seems that all my boards have landed unharmed at maguras place.

 

[Zen Mod]

Morten, how do I find the correct CT point on this one? Is it simply the 2 in the middle?
No prob's finding two windings

with L meter

connect two wires and measure ; if you connected them in phase , you'll have mucho L overall , comparing to L of halves

 

[steenoe]

Cool you have turned this old thread back on - and it seems that all my boards have landed unharmed at maguras place.

Hi cvi

with L meter

connect two wires and measure ; if you connected them in phase , you'll have mucho L overall , comparing to L of halves

Thanks. It says 205mH no matter which two I connect together. Each winding is 48mH.

 

[Magura]

Cool you have turned this old thread back on - and it seems that all my boards have landed unharmed at maguras place.

Oh, you're still alive and kicking

Yes, the boards has landed in Denmark.

Some has taken off to Austria, some to Italy, so now I'm just about out of boards.


Magura

 

[Magura]

Hi cvi



Thanks. It says 205mH no matter which two I connect together. Each winding is 48mH.

You can't measure it like that, when it has no core.


If the other coil is not powered, it's just dead metal in a bad place, so you get a smaller reading on the L meter.

Magura

 

[Zen Mod]

.......... It says 205mH no matter which two I connect together. Each winding is 48mH.

my trusty (memeasurefookineverythin' " ) russkie meter always tells me when windings are outa phase .

OK - then just stay with MetalDanske's recipe , then CRO will tell if you have something out of phase .

 

[Magura]

my trusty (memeasurefookineverythin' " ) russkie meter always tells me when windings are outa phase .

Cause it is Ruskie, as in higher current.

Me thinks modern el-cheapo L-meter is not able to deal with dual air core. Me also had problems measuring



Magura

 

[cviller]

Oh, you're still alive and kicking

Yes, the boards has landed in Denmark.

Some has taken off to Austria, some to Italy, so now I'm just about out of boards.


Magura

I'm kicking alright!

You haven't signed up for any F5 pcbs... have you built one already?

my trusty (memeasurefookineverythin' " ) russkie meter always tells me when windings are outa phase .

OK - then just stay with MetalDanske's recipe , then CRO will tell if you have something out of phase .

Might be a silly question but do you actually want the windings to be in phase or out of phase? The setup is differential, so in phase would be out of phase or what?

 

[Zen Mod]

Cause it is Ruskie, as in higher current.

....

me likee russkie

where are my capicapi russkie piccies ?

 

[steenoe]

When I connect the two long ends as CT. the meter says 2,3mH Something works, maybe not all though. Each half is 48mH and both windings in || also says 48mH.

 

[Magura]

where are my capicapi russkie piccies ?

Here

http://www.diyaudio.com/forums/attachment.php?s=&postid=1690821&stamp=1229797601


Long white thingies.


Magura

 

[Magura]

You haven't signed up for any F5 pcbs... have you built one already?

Naah, I've auditioned an F5, that will do


Magura

 

[Magura]

Might be a silly question but do you actually want the windings to be in phase or out of phase? The setup is differential, so in phase would be out of phase or what?

To be honest, I can't remember, but what I do recall, is that you have no doubt if you have it hooked up right.

A weak memory of connecting the coils out of phase is surfacing though.


Magura

 

[Manu]

Seems ya have to visit me in BETSCH Sasha ... sorry ...

 

[Magura]

When I connect the two long ends as CT. the meter says 2,3mH Something works, maybe not all though. Each half is 48mH and both windings in || also says 48mH.

I suspect that the meter is not up to the task. I have found, that the higher DCR a coil has, the further the reading has been off. I never had this sort of issues, with the big low DCR inductors.


Magura