[Amps] Fw: Step Start on a 3KA Amp

[PA3DUV]

Hal,

The softstarter in the Emtron amps is a phase control triac system, not a 
zero crosser. It allows gradually more of the primary AC sinewave into the 
powersupply. By doing so there is no need for a series resistor to limit the 
inrush current.
Although the series resistor current limiter is effective I consider the 
phase control system more gracious.

I have put a quicktime movieclip on 
http://ph.groups.yahoo.com/group/ham_amplifiers
showing the softstarter power up a lightbulb.

Cheers, Dick
PA3DUV



----- Original Message ----- 
From: "Harold Mandel" <ka1xo at juno.com>
To: "'PA3DUV'" <pa3duv at planet.nl>
Sent: Thursday, September 21, 2006 1:26 PM
Subject: RE: [Amps] Fw: Step Start on a 3KA Amp


> Dick,
>
> I think the Emtrons are zero crossers.
>
> Pat Stein uses them in the Commander series, too.
>
> The amp never makes a thump when it's switched on,
> not like the Alpha clone that makes the floor jump.
>
> Hal
>
>> Ian,
>>
>> A picture of the Emtron switched mode softstarter + schematic diagram are
>> available at:
>>
>> http://ph.groups.yahoo.com/group/ham_amplifiers/photos
>>
>> I've heard that Emtron is selling their softstarter as a seperate item.
>> This softstarter is a small switcher which chops the AC voltage, by doing
>> so limiting the inrush current.
>>
>> Cheers, Dick
>> PA3DUV
>>
>
>