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#127389 - 06/18/01 08:38 PM Choke Transformer Schematic  
Scott35  Offline

Broom Pusher and
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Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
[Linked Image]

This connection is similar to the "Boost" transformer, except the relative polarity is Series Subtractive, plus the connection creates a "Choking Effect" on the current that flows through the secondary coil - hence the name "Choke Transformer".
This lowers the voltage, plus limits the current.
The current limiting action is similar to how a Ballast functions [Typical Magnetic Reactor, HX, CWA Ballasts used for HID and Fluorescent lamps].
Maximum output current is based on the secondary winding's ability to create current, so the short circuit current would be what ever the secondary coul can produce [same as the reactor type Ballast].
Total KVA that can be drawn through the secondary is figured same as any other Buck/Boost transformer - % of Pri/Sec voltage
Example: 120 x 12 VAC - 1 KVA = 1000% of 1 KVA , or 10 KVA max.
Another example: 240 x 12 VAC - 1 KVA = 500% of 1 KVA, or 5 KVA max.

Hope everyone likes these schematics!!

Any comments??? [Linked Image]

Scott SET

[This message has been edited by Webmaster (edited 06-18-2001).]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

Tools for Electricians:

#127390 - 06/19/01 06:39 AM Re: Choke Transformer Schematic  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,303
Scott,
i don't get it... what math is involed in the auto-X to figure 277 x 37 vac to an Es of 240vac?

p.s- go slow, i'll take my boots off and be good up to 20...

[Linked Image]


#127391 - 06/20/01 09:18 PM Re: Choke Transformer Schematic  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Steve,

This setup does the 'ol Series-Subtractive thing on the voltage.

The position of the relative polarity between Primary and Secondary in this connection causes the created voltage to be reduced, instead of combined [added].
Now, the output voltage will be Epri minus Esec [or 277 minus 37].

Kind of interesting little thing, is'nt it??

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127392 - 06/20/01 11:19 PM Re: Choke Transformer Schematic  
Anonymous
Unregistered

The location of the phase points on the buck and boost transformer make sense to me.

On this diagram, they don't.

E.s has a ø on both sides of it and I would say that just can't be.

I suspect that the ø by X1 belongs by X2 instead.


#127393 - 06/24/01 02:38 PM Re: Choke Transformer Schematic  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,303
bad things would happen if the H1-H2 coil were to open... [Linked Image]


#127394 - 06/25/01 04:14 PM Re: Choke Transformer Schematic  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Dspark,

In a way, this arrangement resembles a "Buck" transformer, just that it's not connected as an Autotransformer with a tap out of the coil between the input lines [tapped coil for voltage reduction]. If this is unclear, the opposite would be an Autotransformer with an extended coil's length to increase the voltage - making it equal to the "Boost" transformer.

Here we have made connections so that they fall out of polarity with the current flow. Simply we have reduced the voltage and choked the currents because they are not in step with the core's flux polarity. This makes the effects series subtractive for the voltage, plus restricts the currents flowing in the long run [similar to the typical reactor].

Best thing here is to view only the single line schematic so the connections to polarities thingee is unmasked.


Steve,

You're right about the results of the primary coil opening.
That would make the circuit have no polarity to work against, plus minimal core effects - making the secondary coil act only as a filter section, instead of a current choke and part of a voltage reduction circuit.

Scott SET

P.S. had to edit after posting due to crazy looking typo's!! [Linked Image]
SET.

[This message has been edited by Scott35 (edited 06-25-2001).]


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127395 - 07/05/01 05:33 PM Re: Choke Transformer Schematic  
Anonymous
Unregistered

>In a way, this arrangement resembles a "Buck" transformer,
...except that X1..X2 is flipped over.

It took me a while to get it.

I guess to avoid crossing lines, X1..X2 is turned over in the pictorial view which made the diagram look like the buck transformer with the X1 and X2 terminals transposed.
A "sloppier" picture that retained the X1..X2 orientation would have processed more easily in my brain (so much so that I still feel that the pictorial diagram is not so pictorial).

But the topology of this transformer is distinctly different from boost and buck.
It seems to me that there should be an "induce" transformer to complete the set. It would be like the choke xformer with the primary and secondary swapped. Do you have a design like that?


#127396 - 07/07/01 07:32 PM Re: Choke Transformer Schematic  
Scott35  Offline

Broom Pusher and
Member
Joined: Oct 2000
Posts: 2,707
Anaheim, CA. USA
Dspark,

The problem I created on these drawings was using the term "Pictorial" on the schematic that is located at the top.
It is a 1 line diagram, just as the lower drawing is.
Anyone have a better term I could use in place of "Pictorial"??? Something like "1 line layout" might be the better term.

Anyhow, this "noodle" [compliments of "Sparky" Steve [Linked Image]], would do it's thing by the repulsion created when driving currents through subtractive XL's at an opposite direction to the core's flux [if that makes any sense [Linked Image]].

Think of it as being an Inductive Reactor [Reactor Core type ballast], in series with an Autotransformer which steps down the input voltage.
Kind of like an HPS ballast!

This might be the circuit example you are reffering to at the end of your last message.

I'll post some Ballast drawings ASAP, plus a few Rectifier [DC converter] circuits, a couple AC motor drawings [hopefully some simple control ladders, too!], a few more filters [including passive crossovers], and some simple Inverter circuits.
If possible [and wanted], I'll throw in some Electronic circuits. Mainly basic ones, nothing too complex.

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

#127397 - 07/12/01 01:55 PM Re: Choke Transformer Schematic  
JBD  Offline
Member
Joined: Jul 2001
Posts: 599
WI, USA
Scott
For new descriptions you could use:

Wiring diagram - shows actual physical relationships

Elementary diagram - shows electrical connections without regard to physical location (often called one-line diagrams)



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