[Amps] Step Start

[sccook1@cox.net]

Seems like the delay would only need to be long enough to limit the inrush current to the safe level specified for the tube filament and power supply diodes.  In most cases I've encounter, 1/2 to 1 second is plenty.

Steve
WG7K


> 
> From: "Larry Carman" <lncarman at swbell.net>
> Date: 2005/08/12 Fri AM 10:27:44 EDT
> To: <amps at contesting.com>
> Subject: Re: [Amps] Sort Start
> 
> The Henry RF generator using a 4 KW power supply at 4000 VDC and a filter
> choke
> only use a .5 second soft start. The 1/2 second delay seems to be plenty
> even
> with 30 mf of caps and no filter choke.  I've been running this arrangement
> or years. Too much soft start in certain instances will cause the bypass
> relays
> to energize too slow and cause relay clattering amongst other problems.
> 
> Regards,
> Larry N5BIP
> 
> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]On
> Behalf Of Will Matney
> Sent: Tuesday, August 09, 2005 11:30 AM
> To: amps at contesting.com
> Subject: Re: [Amps] Sort Start
> 
> 
> You can add a soft start, some do and some don't. A 10 second delay though
> is a little too long for the soft start on the HV transformer. You only need
> about 4 to 5 seconds as that's actually over the time it takes for the
> transformer to settle down. Some circuits are a little faster than that.
> 
> Best,
> 
> Will
> 
> *********** REPLY SEPARATOR  ***********
> 
> On 8/9/05 at 11:15 AM Rich wrote:
> 
> >Gentleman, I have started bread boarding my power supply.  So far I have
> >it set for the filament transformer and fan to come on first, run for 3
> >( adjustable ) min then kick in a relay for 0 to280v to the HV trans , I
> >have a 50ohm 100 watt resistor in line for 10 sec then full voltage (as
> >set by the autotransformer) to the HV transformer.
> >The caps bank will be 33uF at 6000vdc ( 3 caps 100mF 2000vdc each ),
> >transformer will be set 3000 to 40000vdc.
> >Before I bolt it all down and hard wire it do I need a soft start for
> >the filament?
> >The tube is a 4-1000a
> >
> >Rich , kd0zz
> >
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> 
> 
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