Low Crack Voltage

Hi-Q · 1891

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Offline Hi-Q

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on: August 06, 2013, 05:03:59 AM
Hi,
Sorry my english not good.

I measure the voltage PT-3 from output 149VAC. It seems correct, right?
The problem is terminal 13 (B+) measured only 150VDC.

Everything is working correctly.
But why B+ is too low?

Thanks!
« Last Edit: August 06, 2013, 05:24:06 AM by Hi-Q »



Offline Paul Joppa

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Reply #1 on: August 06, 2013, 11:29:09 AM
We do not however have transformers with 100v primaries, as used in Japan. If you have 100vAC power, then you need a step-up transformer to generate 120vAC.

Paul Joppa


Offline Hi-Q

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Reply #2 on: August 06, 2013, 04:52:21 PM
Input voltage +-223VAC.

Measured output voltage is 149-150VAC.
The transformer labeled at 150VAC, I think it's already good.

Based on the calculation, I must increase secondary output higher than 160V. It means the transformer has wrong label, right?  ???

So how much secondary AC voltage needed to make 170VDC B+?  :o
« Last Edit: August 06, 2013, 05:18:45 PM by Hi-Q »



Offline Paul Birkeland

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Reply #3 on: August 06, 2013, 08:45:50 PM
Please proceed with construction of the kit and report any DC voltage problems present (I do not believe you will encounter any).

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Hi-Q

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Reply #4 on: August 07, 2013, 05:45:06 AM
yes,
i already told you, my crack running well. ::)

my question is how much secondary AC voltage needed to make 170VDC B+?



Offline Paul Joppa

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Reply #5 on: August 07, 2013, 12:34:37 PM
Sorry, my mistake. 150vAC with 220vAC supplied to the 240v transformer, with the tubes operating, should be about 150vAC on the high-voltage winding. That should make about 155vDC with the Crack power supply, so your voltages are as expected, and within the range for correct operation.

Paul Joppa


Offline netmask254

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Reply #6 on: September 09, 2013, 03:08:08 AM
Just want a double confirm: The 240V transformer shall work well with 220V input voltage without sound quality problem, is this correct? Thanks a lot!



Offline Paul Birkeland

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Reply #7 on: September 09, 2013, 05:30:20 AM
Ah, I somehow missed this.  Yes, 240V on the 220V transformer will work nicely.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man