The Delta-Wye transformation is an extra technique for transforming certain resistor combinations that cannot be handled by the series and parallel equations. This is also referred to as a Pi - T transformation.
Log in Fasteric Algorithm 8 years agoPosted 8 years ago. Direct link to Fasteric Algorithm's post “Why we can assume that te...” Why we can assume that terminal z isn't connect to anything? • (16 votes) APDahlen 8 years agoPosted 8 years ago. Direct link to APDahlen's post “Hello Fasteric,Try to t...” Hello Fasteric, Try to think of each circuit as a black box - assume you don't know what is inside. When you "look" from terminal A to B you see a certain resistance. When you "look" from terminal B to C you see a certain resistance. Finally when you "look" from terminal C to A you again see a resistance. It's important that you "look" at the circuit in isolation. If it was connected to other things it would be difficult to do this thought experiment. Please give it a try you should be able to convince yourself that the wye and delta look the same. If it helps try calculating the resistances when the delta has three resistors each with a value of 3 Ohm. Then try the wye with three resistors each having a 1 Ohm value. Regards, APD (7 votes) Bill Horan 8 years agoPosted 8 years ago. Direct link to Bill Horan's post “Can you provide the work ...” Can you provide the work for solving the 3 simultaneous equations that was not shown? • (6 votes) Bob S 8 years agoPosted 8 years ago. Direct link to Bob S's post “This is awesome. Thank yo...” This is awesome. Thank you for explaining. It's very hard to find a straightforward, detailed explanation of the transformations on the web, but you've presented one here. You should do a YouTube video. It would blow people's minds! (5 votes) 😊 7 years agoPosted 7 years ago. Direct link to 😊's post “I want u to ask a full wa...” I want u to ask a full way to derive R1 and Ra plz give a derivation how we get R1 and Ra ? • (5 votes) _phidot_ 7 years agoPosted 7 years ago. Direct link to _phidot_'s post “since,(resistance betwe...” since, (resistance between X&Y in Y) = (resistance between X&Y in delta) so, To get R1, we do ([1] + [3] - [2]) / 2, at the left hand side : ( (R1 + R2) + (R3 + R1) - (R2 + R3) ) / 2 = (R1+R2+R3+R1-R2-R3)/2 = (2 x R1)/2 = R1 ..[4] Do the same for right hand side : ( ( Rc || Ra+Rb ) + ( Rb || Rc+Ra ) - ( Ra || Rb+Rc ) ) / 2 Since, left hand side = right hand side, or [4] = [5], R1 = (Rb x Rc)/(Ra+Rb+Rc) Done, we got our R1. :D ref : previous question @ (11 votes) Professor6 8 years agoPosted 8 years ago. Direct link to Professor6's post “why would we want to go f...” why would we want to go from y-delta • (5 votes) APDahlen 8 years agoPosted 8 years ago. Direct link to APDahlen's post “Hello Professor,They ca...” Hello Professor, They can be used to simplify the occasional circuit as shown in this video. They really come in handy when working with three-phase system. The transform simplifies the math :) This link may help: http://www.belden.com/blog/datacenters/3-Phase-Power-Wye-It-Matters.cfm Regards, APD (6 votes) emiliano.sanchez5 8 years agoPosted 8 years ago. Direct link to emiliano.sanchez5's post “so if they delta and y ar...” so if they delta and y are then transformed into a combination circuit.. why have those?? • (2 votes) Willy McAllister 8 years agoPosted 8 years ago. Direct link to Willy McAllister's post “One of the common places ...” One of the common places a Delta resistor configuration shows up is in a "bridge" circuit. If you search for "Whetstone Bridge" on the web you will see deltas in the resistor bridge. This circuit is used to make very sensitive differential voltage measurements. (5 votes) Hagar Usama I can derive R1, R2 & R3 easily, but I can't derive Ra at all. I can't figure it out ! • (2 votes) Willy McAllister 7 years agoPosted 7 years ago. Direct link to Willy McAllister's post “Scan down through the com...” Scan down through the comments here and find a response by learner phidot. There's a derivation in two separate comments. (2 votes) popalzaymaiwand 8 months agoPosted 8 months ago. Direct link to popalzaymaiwand's post “A video explanation might...” A video explanation might made it easier to understand. • (2 votes) ChloeM. 5 years agoPosted 5 years ago. Direct link to ChloeM.'s post “If we used these configur...” If we used these configurations for inductors instead of resistors, would that create a magnetic field in the shape of the configuration? • (1 vote) Willy McAllister 5 years agoPosted 5 years ago. Direct link to Willy McAllister's post “In an inductor most of th...” In an inductor most of the magnetic field is concentrated on the inside of the coil. The field is much weaker around the outside of the inductor. If you tuck three straight inductors tight together in a triangle you pretty much get three magnetic fields in a triangle shape. But, if you curve the inductors into a circle the magnetic fields get together to make one more powerful field. See the second to last image of a circular-wound inductor in this article: https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/circuit-elements/a/ee-real-world-circuit-elements (3 votes) poorvabakshi21 8 years agoPosted 8 years ago. Direct link to poorvabakshi21's post “I didn't understand the d...” I didn't understand the derivation of the three simultaneous equations. Can someone please explain them. • (1 vote) melissa 6 years agoPosted 6 years ago. Direct link to melissa's post “I found this video to be ...” I found this video to be very helpful: https://youtu.be/igvqOyJYAoA (2 votes) Andrew Rose 5 years agoPosted 5 years ago. Direct link to Andrew Rose's post “Do these transformations ...” Do these transformations only work for planar circuits, or would they work for 3D structured circuits as well? • (2 votes) Willy McAllister 5 years agoPosted 5 years ago. Direct link to Willy McAllister's post “The Delta-Wye transforms ...” The Delta-Wye transforms work for deltas and wyes, which are 2D arrangements. Most 3D circuits are physics puzzles, like this one, http://web.physics.ucsb.edu/~lecturedemonstrations/Composer/Pages/64.42.html You work these out from first principles or by exploiting symmetries to simplify down to 2D series and/or parallel circuits you do the usual way. (1 vote)Want to join the conversation?
I mean, in the example, it clearly show that terminal z did connect to something and must have a current flow through.
(resistance between Y&Z in Y) = (resistance between Y&Z in delta)
(resistance between Z&X in Y) = (resistance between Z&X in delta)
(R1 + R2) = ( Rc || Ra+Rb ) .. [1]
(R2 + R3) = ( Ra || Rb+Rc ) .. [2]
(R3 + R1) = ( Rb || Rc+Ra ) .. [3]
=( (Rc x (Ra+Rb))/(Rc+(Ra+Rb)) + (Rb x (Rc+Ra))/(Rb+(Rc+Ra)) - (Ra x (Rb+Rc))/(Ra+(Rb+Rc)) ) / 2
=( ((Rc x (Ra+Rb)) + (Rb x (Rc+Ra)) - (Ra x (Rb+Rc)) / Ra+Rb+Rc ) / 2
=( ((RbRc+RaRc) + (RaRb+RbRc) - (RaRb+RaRc)) / Ra+Rb+Rc ) / 2
=( (2 x RbRc) / Ra+Rb+Rc ) / 2
=(RbRc)/(Ra+Rb+Rc) .. [5]
https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/ee-resistor-circuits/a/ee-delta-wye-resistor-networks?qa_expand_key=kaencrypted_ad2413cde556298b64a98d41d01fd684_cd6a16e8a8a657a21f768c0ff04804160d977a939ac691b3ecd6f7ee4a7f3b908c3a74bcab01337d6533d3b2cd73bf8f6ff245d796c6ba5cd4935e7434b49ff5a41f9fde6e3e3b40568f65d949ebef1c2069c478d967b52cc4b9a4782497244937b838cd8908e0ad3a3a524e87a524e6f816e4f6f1312d1554b5f5586074aab1f7d6c61e4d62263fecf53eb29522e61469af6deb96ff91ae7303c04481bb2de0
