[Jukebox-list] Selenium Rectifier

[Don]

Usually when you see a center tapped secondary winding powering a two diode 
rectifier you need to watch to see if the center tap also serves as the 
ground reference.   I think putting a four diode bridge across the whole 
transformer secondary complicates things.... you get about double the 
voltage which is not what the loads want.... even if you put a bridge from 
center tap to one end of the secondary and another bridge from center tap to 
the other end of the secondary, then tied the bridge outputs together 
properly you run shorting risks in the bridges when their diodes have 
extremely small differences in switching times.... ergo they'll run hot even 
in the best case scenario... even if this would seem to work it seems one 
risks overheated bridges and also the possiblility that the wire size in the 
transformer secondary would not be correct for the changed current demand.
Ron is right, it was engineered for two diodes..... leave good news alone.
Cheers,
Don


----- Original Message ----- 
From: "Ron" <tracron at bigpond.net.au>
To: "Jukebox mailing list" <jukebox-list at lists.netlojix.com>
Sent: Tuesday, May 01, 2007 9:13 AM
Subject: Re: [Jukebox-list] Selenium Rectifier


> The two diode design works well, leave it.
> There is no advantage trying to modify it.
> May be to high a voltage from the diodes since the selenium rectifier has 
> been replaced, just check the voltage.
> 30 volts sounds okay I think it should be around 28V .
> Ron from OZ
> ----- Original Message ----- 
> From: "Jim Poe" <jpoe at dsldata.com>
> To: "Jukebox mailing list" <jukebox-list at lists.netlojix.com>
> Sent: Wednesday, May 02, 2007 1:29 AM
> Subject: Re: [Jukebox-list] Selenium Rectifier
>
>
>> When I was working on my AMI G-200, I was going to replace the diodes in 
>> the power supply with a bridge.  Got it wired up, & realized I had 60 
>> volts instead of the required 30.  The transformer has center tap that is 
>> 30V.  Not being that knowledgeable, I went back to 2 diodes as the 
>> original design.  Is there a way to get the bridge to work in that 
>> situation, where the transformer has a center tap & each side is 30V? 
>> Could I only use 1 side of the transformer?
>>
>> Thanks
>> Jim
>
>
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