Re: Using SCR's For Regulating Input Current (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Tue, 08 Feb 2005 22:15:13 -0600
From: Shaun Epp <scepp@xxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Using SCR's For Regulating Input Current (fwd)

I should have added,  In a switched bridge configuration the two SCR's 
connect to two diodes.  Since you module had three heavy terminals, this is 
one configuration.  You wouldn't want to use a switched bridge on a 
transformer though.  So back to back SCR's is the way to go.

Shaun Epp


----- Original Message ----- 
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: "hvlist" <hvlist@xxxxxxxxxxxxxxxxx>
Sent: Tuesday, February 08, 2005 7:41 PM
Subject: Re: Using SCR's For Regulating Input Current (fwd)


> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Thu, 03 Feb 2005 22:21:50 -0600
> From: Shaun Epp <scepp@xxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: Using SCR's For Regulating Input Current (fwd)
>
> The application is called "phase control", and you'll need more that a
> potentiometer to control it.  Look up motor speed controls, lamp dimmers 
> and
> phase control on google, you'll probably find the information you need. 
> The
> current will be pulses timed with the line frequency to turn on the SCR's 
> a
> number of milliseconds after each zero crossing that way limiting the
> average current and voltage to the load.  Two SCR's would be a switched
> bridge configuration.
> Your peak current each time the SCR's fire will be high.
>
> Good luck,  that's alot of power your dealing with
>
> Shaun Epp
>
> ----- Original Message ----- 
> From: "High Voltage list" <hvlist@xxxxxxxxxx>
> To: "hvlist" <hvlist@xxxxxxxxxxxxxxxxx>
> Sent: Thursday, February 03, 2005 4:28 PM
> Subject: Using SCR's For Regulating Input Current (fwd)
>
>
>> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>>
>>
>>
>> ---------- Forwarded message ----------
>> Date: Mon, 31 Jan 2005 10:57:56 -0600
>> From: Carl Litton <Carl_Litton@xxxxxxxxxx>
>> To: High Voltage list <hvlist@xxxxxxxxxx>
>> Subject: Using SCR's For Regulating Input Current
>>
>>
>> Would someone please explain how the brick-like high current 'power
>> module' blocks containing 2 SCR's are used to regulate current?  We are
>> interested in pursuing this as an alternative to heavy/bulky variable
>> inductors.
>>
>> We have such a module rated at about 250 Amps continuous and 1200 Volts.
>> It has the 3 main terminals: 1 for AC in and 2 (+/-) used to connect the
>> SCR's and provide output.  It also has four small terminals, 2 to the
>> gates of the SCR's and 2 to the cathodes of the SCR's.
>>
>> We have been given to understand that such a module may be placed in 1
>> leg of the AC input line (along with a potentiometer and such) to
>> regulate the input current as a sort of pulse width modulator.  Current
>> demand on our input line is about 80-120 Amps and we would like to
>> restrict it to a variable 25 to 60 Amps with this type of setup.
>>
>> We would appreciate a brief description of such a control circuit or a
>> link to the explanation and/or a schematic.
>>
>> Thank you,
>>
>>
>> Carl Litton
>>
>>
>>
>>
>
>
>
>