The diagrams I looked at came from here:
ok1hra.nagano.cz/Expert_Schematic_diagramsII.pdf
I can't see any mains filtering, and no power factor correction.
The repairs on my friend's amp required no more than removing the lid,
so I can't vouch for what's actually inside the box.
What's the power limit for when power factor correction is required?
Steve
On 07/03/13 10:05, peter chadwick wrote:
Steve, How much filtering is there to meet EU regs on noise put on
the mains, and is there any power factor correction circuitry? 73
Peter G3RZP
======================================== Message Received: Mar 07
2013, 08:50 AM From: "Steve Thompson" To: amps@contesting.com Cc:
Subject: [Amps] Expert 1k amp
Yesterday I did some minor repairs to a friend's amp - resoldering
joints on the current sensing resistor. Looking at the circuits later
I noticed that the main supply voltage is regulated by having SCRs in
place of diodes rectifying the transformer secondary and the main
smoothing capacitor is 47000uF.
My friend tells me the amp runs over 40A at full tilt, which means
something like 8.5V ripple on the supply (7V at 60Hz). That strikes
me as quite high and I'd expect to see some difference in amplifier
gain/output if I was running such an amp off a regulated supply and
altered the voltage that much. Has anyone measured one? Is any
100/120Hz audible on a carrier?
Steve _______________________________________________ Amps mailing
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