Flux Paths in a Saturable Core Reactor

[Randy Gross]

Please view in a fixed-width font such as Courier.


Legs:1 2 3 4 5
____________________________________________________________
| ->__ -> <- ___ <- |<- ___ <- -> ___-> |
| |___|_______________|___| |___|_____________|___| |
| | | | | | |
| | Coil wound | | Coil wound | |
| ^| ----->>>> | | | <<<<----- | |
| ||_______________________| |_____________________|| |
| | | |___|___|___|___| | |v |
| | | | | DC Control | | | |
| | | v | Winding | ^ | | |
| | | |_______________| | | | |
|__|___|_______________|___|___|___|___|_____________|___| __|
| <- <- -> Flux -> -> Path -> <- <- |
|______________________________|_____________________________|


All of the information I could gather on this subject, describes the
configuration of this device as either a 3 leg core, 2 Tories, a U core or
ELI. I could not locate any descriptions for the ELI core.

Pictured above is a depiction of how I think the cores would be
arranged(based on descriptions stating that the flux path is canceled in
the leg containing the control winding to prevent induced voltage).

NOTE: Please bear in mind that this is only a thought at this point. No
components have been gathered or assembled.

Am I on the right track here?

 

[Eric Y. Chang]

Randy Gross ([email protected]) wrote:

: All of the information I could gather on this subject, describes the
: configuration of this device as either a 3 leg core, 2 Tories, a U core or
^^^^^^^^^^
: Am I on the right track here?

Almost.

The way these things are usually constructed is with 3 legs. The
reason is that the outer legs in your diagram are not really necessary
for operation, and in fact, they actually detract from the effectiveness
of the design because they leak flux further outside the saturated
(center leg) region. Imagine what your device looks like and operates
with the two outer legs removed. You could also use two toroids that
are side by side.

One minor warning is that the weight of the higher current devices can
get kind of large.

 

[Randy Gross]

You confirmed my concern about the first and fifth legs in the diagram. The
extra paths would present a problem. I couldn't conceive of how the SCR was
constructed with an EI core unless the unit was massive.

Thanks Eric for the reply,

Randy Gross

<[email protected]>...
: Randy Gross ([email protected]) wrote:
:
: : All of the information I could gather on this subject, describes the
: : configuration of this device as either a 3 leg core, 2 Tories, a U core
or
: ^^^^^^^^^^
: : Am I on the right track here?
:
: Almost.
:
: The way these things are usually constructed is with 3 legs. The
: reason is that the outer legs in your diagram are not really necessary
: for operation, and in fact, they actually detract from the effectiveness
: of the design because they leak flux further outside the saturated
: (center leg) region. Imagine what your device looks like and operates
: with the two outer legs removed. You could also use two toroids that
: are side by side.
:
: One minor warning is that the weight of the higher current devices can
: get kind of large.
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:

 

[Harry Dellamano]

Please view in a fixed-width font such as Courier.


Legs:1 2 3 4 5
____________________________________________________________
| ->__ -> <- ___ <- |<- ___ <- -> ___-> |
| |___|_______________|___| |___|_____________|___| |
| | | | | | |
| | Coil wound | | Coil wound | |
| ^| ----->>>> | | | <<<<----- | |
| ||_______________________| |_____________________|| |
| | | |___|___|___|___| | |v |
| | | | | DC Control | | | |
| | | v | Winding | ^ | | |
| | | |_______________| | | | |
|__|___|_______________|___|___|___|___|_____________|___| __|
| <- <- -> Flux -> -> Path -> <- <- |
|______________________________|_____________________________|


All of the information I could gather on this subject, describes the
configuration of this device as either a 3 leg core, 2 Tories, a U core or
ELI. I could not locate any descriptions for the ELI core.

Pictured above is a depiction of how I think the cores would be
arranged(based on descriptions stating that the flux path is canceled in
the leg containing the control winding to prevent induced voltage).

NOTE: Please bear in mind that this is only a thought at this point. No
components have been gathered or assembled.

Am I on the right track here?

Hi Randy,
Check this out.
http://www.tpub.com/neets/book8/32n.htm

enjoy
harry

 

[Randy Gross]

This is a great site for the SCR. It described the unit in detail as well
as the Magnetic Amplifier. The three leg core and the torroidal cores are
the norm for this design.

Thanks Harry,

Randy Gross


<[email protected]>...
!
: >
: Hi Randy,
: Check this out.
: http://www.tpub.com/neets/book8/32n.htm
:
: enjoy
: harry
:
: