[Amps] Direct rectification of AC mains to drive the amp,

[peter chadwick]

Bill,

As I understand it - and quite likely I' m wrong - with a normal rectifier and input C, the rectifiers draw current only when the transformer volts exceed the reservoir capacitor volts. This puts a large harmonic component on the input which isn't in phase. Using a switching  'boost inverter' allows the supply current to effectively see a resistive load.

I know the people at Alpha were telling me that meeting EU requirements was difficult with a usual transformer/ rectifier/capacitor supply, but I don't know how they got over that.

With some years of professional experience regarding EU requirements and their development, I personally feel that the Commission people have all demonstrated that they are a useless load of idiotic incompetents, busily trying to legislate things they do not understand.......

thank heavens I've retired.....





========================================
 Message Received: Sep 27 2013, 05:04 PM
 From: "Bill Turner" <dezrat1242 at yahoo.com>
 To: "Amps" <amps at contesting.com>
 Cc: 
 Subject: Re: [Amps]  Direct rectification of AC mains to drive the amp,
 
 ORIGINAL MESSAGE:          (may be snipped)
 
 On Wed, 25 Sep 2013 10:10:06 +0930, you wrote:
 
 >
 >Yes all that you mention below is correct Jim. That's why I commented in an
 >earlier post that an individual QRO amp builder would get away with doing
 >this questionable 3 kW power supply realization technique, but no commercial
 >SS amp manufacture would be able to do this due to the electrical codes in
 >respect of EU power factor rules and product compliance certification.
 
 REPLY:
 
 Power factor correction is an area I am a bit hazy on. Could someone explain
 why the power factor would be different between a direct-rectified PS and a
 transformer-isolated one? Either one charges the capacitors with a series of
 pulses. What's the difference in power factor?
 
 73, Bill W6WRT
 _______________________________________________
 Amps mailing list
 Amps at contesting.com
 http://lists.contesting.com/mailman/listinfo/amps