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Trouble with Rod Coleman DHT reg

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67339

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Joined 2002
Hello,
I will use the Coleman regulator in the near future.i asked him some questions before deciding to buy it when I am back home. From what I read so far it is clear that you need a minimum input to get the right output. But I think the problem is outside the regulator. ROD will answer here soon.greetings, eduard
 
6

67339

Disabled Account
Joined 2002
andyjevans said:
Yes indeed. The Ver. 7 requires less headroom than previous versions which were good at around 6v-7v headroom but even so, I'd suggest 5v. Rod will tell you.

Why not choke input? I'd be doing that with a big chunky 18v transformer without much voltage drop.
Click to expand...

Hello,
I also think choke input is the way to go. Depending on the current you can use lundahl ll1694 or ll2733 both are so called filament chokes designed for higher currents. Not sure if an ordinary transformer will not saturate or will lack enough my for proper choke input.greetings, eduard
 
merlin el mago

merlin el mago

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Joined 2009
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cowneko said:
Hi everyone,

I'm converting my raphaelite CSK30 to monoblocks and I wish to integrate the rod coleman regs V7 I assembled some months ago.

I'm in the testing phase and I encounter a strange behaviour, seems like not enough current is fed to the reg, witch seems odd.

My PT is a PW300ABA-230 from raphaelite

390V - 320V - 100V - 0V - 320V - 390V at 300mA
5V at 4A (for the rectifier)
6.3V at 4A ( for common input pentode tubes)
2X 5V - 2.5V - 0V

I decided to wire the two 5V secondaries in serie to obtain 10V at 4A witch should be enough to feed the reg board.

An externally hosted image should be here but it was not working when we last tested it.

This is the way my secondaries are wired.

An externally hosted image should be here but it was not working when we last tested it.


This is the PSU I made on a breadboard.
R1 and R2 are 0R22 5W

The Coleman Reg R20=1K, Reg R1=0R82 5W
The Dummy res connected to reg output is 3R1 20W (10R 10W + 4R7 10W) that was all I had on hand to mimic a 300B.

The PSU gives 14.423V DC unloaded, so fine.

But as soon as I wire the reg board The Psu outputs 5.185V DC ??

Regboard output (with 3.1ohm dummy resistor) gives 2.71V DC
0.856A between PSU + output and regboard + input

the output does not seem to change much by altering the RV1 pot on the regboard.

Something is not working fine here. Rod asked to invert the phase of one of my secondaries, but I don't really know how to do this in my configuration.

Any clues?
Click to expand...


Try attached pic.
 

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E

euro21

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Joined 2004
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cowneko

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Joined 2013
Well I tried with a new PT, an indel 2X9V at 2,22A in parallel so 9V at 4,44A
I also changed the diodes for 1N5822 and caps for Samwha HC 10000uf 35V.

i got exactly the same behavior :(

Here,s the full setup and numbers I found:

PSU Part:
An externally hosted image should be here but it was not working when we last tested it.

R1= 33ohm 3W (that's the only 33R I got on hand)
C1 and C4 = Wima mks 220nf 63V
D1= 4x 1n5822
C2 and C3= Samwha HC 10000uf 35V
R2 and R3= 0,22ohm 5W

Reg Parts:
Q1 and Q6= BC546
Q2 and Q3= BC549 (not sure for Q3 as I cannot see the markings)
R1= 0,82ohm 5W
R20= 1K
R24= 33ohm
Dummy load= 4,7ohm 10W

Measures:

Mains= 231,6V AC RMS
PT out unloaded= 10,1V AC RMS
PSU out unloaded= 13,743V DC

PT out loaded (with RV1 fully anticlockwise)= 9,80V AC RMS
PT out loaded (with RV1 fully clockwise)= 9,76V AC RMS

PSU out loaded (with RV1 fully anticlockwise)= 4,380V DC
PSU out loaded (with RV1 fully clockwise)= 4,500V DC

Filament out (4,7ohm 10W load) with RV1 fully anticlockwise= 2,5V DC
Filament out (4,7ohm 10W load) with RV1 fully clockwise= 2,56V DC

Current PT out loaded= 0,671A AC
Current PSU out (+ wire) loaded= 0,5A DC
Current measures have been taken with a clamp meter on 2A caliber.

I don't get what's going on :(
 
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