Timeline for Art Of Electronics - Center Tapped Transformer Efficiency and Current Question, LTSpice Question too
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| Jan 14, 2017 at 21:47 | history | edited | rioraxe | CC BY-SA 3.0 |
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| Jan 14, 2017 at 14:22 | comment | added | Jeffrey Edward Messikian | I see how the full coil is used in the full wave bridge, verses the half in the center tapped (on each half cycle). Are you, and the book, implying that the number of windings in W1 and W2 need to change between designs to get the voltage to where it needs to be? If so, and we did this, wouldn't it make sense to use fatter wires when more current was needed? | |
| Jan 14, 2017 at 14:22 | comment | added | Jeffrey Edward Messikian | If I had a load on the center tapped transformer that required 5V at 2A and that design fit the bill ok. If I then took that same load and placed it on the top design, the full wave bridge, would that design be supplying 10V at 1A, because of the parallel W1 and W2? If so, I can see the power being the same but the current halved. But, in both cases the load needed 5V, not 10V. I was assuming the output was exactly the same. | |
| Jan 14, 2017 at 6:07 | comment | added | rioraxe | During the half cycle when the top of the windings is positive, the possible path of current flow is from top of the windings, through D5, through the load, through D1 back to bottom of windings. During the opposite half cycle when the bottom is positive, bottom -> D4 -> load -> D2 -> top. | |
| Jan 14, 2017 at 1:54 | comment | added | Jeffrey Edward Messikian | In the top image, When the input sine wave transitions say from 0-1-0, at this point W1 and W2 conduct and current flows to D4 and D5? Correct? When the sine wave goes from 0 to -1 and back to 0, the voltage is negative, and current is pulled from d1 and d2, if ground sourced current.which it doesn't, hence the, the half cycle. right? | |
| Jan 13, 2017 at 22:29 | comment | added | rioraxe | While the one compiling reason to go center-tapped configuration would be if both positive and negative outputs are needed, which your pasted image seems to be getting to. | |
| Jan 13, 2017 at 22:28 | comment | added | rioraxe | Go look up some actual transformer (for DC power supply applications) datasheets, you would probably find that the most common configuration of the transformers is the split output windings like above. For the same equivalent output voltage, you can connect the windings in parallel to get better current characteristic (as explained in the pasted image) but extra diodes and one extra diode voltage drop. Or connect the windings in series for center-tapped for less diodes. | |
| Jan 13, 2017 at 21:46 | vote | accept | Jeffrey Edward Messikian | ||
| Jan 13, 2017 at 21:45 | comment | added | Jeffrey Edward Messikian | This is interesting. The bottom image is definitely the center tapped transformer in the book. In the top image, can you explain the transformer a little? I see the transformers are equivalent except for the center tapp, but what are the outputs in the top transformer? The bottom transformer should have only two, which it does, the top should have just one? In the top image, W1 and W2 look parallel, what does that do? I guess that is double the windings? | |
| Jan 13, 2017 at 21:02 | history | edited | rioraxe | CC BY-SA 3.0 |
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| Jan 13, 2017 at 20:55 | history | answered | rioraxe | CC BY-SA 3.0 |