Differences

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--- other:electronics:rectifier-circuit [2024/06/04 17:42] – [Calculation of ripple Factor] oscar
+++ other:electronics:rectifier-circuit [2024/06/14 12:34] (current) – [Transformer Selection] oscar
@@ Line 26: / Line 26: @@
   * ''** V//rms// = V//p// / √(2) **''
   * ''** V//rms// = V//pp// / (2 * √(2)) **''
-  * ''** V//pp// = √(2) * V//rms// **''
+  * ''** V//pp// = 2*√(2) * V//rms// **''
 ==== Triangle ====
@@ Line 81: / Line 81: @@
   * ''** Ripple factor =  √ ( ( V//rms// / V//dc// )² - 1 ) **''
   * ''** Ripple factor =  √ ( ( I//rms// / I//dc// )² - 1 ) **''
-==== DC output Voltage ====
+==== DC output Voltage ====
+**Please note:** the calculations below only work if the RC time is >> (x10) then the period T.
+E.g. in case of 100 hz (T=10ms) the RC should be in the range of 0,1 (100 ms) = 100 Ohm * 1000uF.
+{{ :other:electronics:rectifier-ripple.jpg?600 |}}
 For a full wave rectifier with filter the output voltage can be calculated with the following formula:
   * ''** V//dc// =  V//p// - ( I//dc// / 4fC ) **''
 Substituting I//dc// with V//dc// / R this becomes:
   * ''** V//dc// =  V//p// * 4fRC ) / ( 1 + 4fRC ) **''
+===== Transformer Selection =====
+Based on the above formulas, the table below calculates the required tranformer voltage to achieve a specific DC voltage.
+^Preferred Vdc^Stabilizer drop (V)^Vp^Rectifier Drop (V)^Trafo Vpp^Trafo RMS^
+| |  -3  | |  -1,4  | | |
+|  5  |  8  |  8,0  |  9,4  |  18,9  |  6,7  |
+|  9  |  12  |  12,1  |  13,5  |  26,9  |  9,5  |
+|  12  |  15  |  15,1  |  16,5  |  33,0  |  11,7  |
+|  15  |  18  |  18,1  |  19,5  |  39,0  |  13,8  |
+|  16  |  19  |  19,1  |  20,5  |  41,0  |  14,5  |
+|  18  |  21  |  21,1  |  22,5  |  45,0  |  15,9  |
+|  20  |  23  |  23,1  |  24,5  |  49,0  |  17,3  |
+|  24  |  27  |  27,1  |  28,5  |  57,1  |  20,2  |
 ===== Links =====
   * https://en.wikipedia.org/wiki/Rectifier
@@ Line 93: / Line 112: @@
   * https://www.studocu.com/en-za/document/central-university-of-technology/electronic-fundamentals-i/unit5-power-supply-design-3/14924637
   * https://gtuttle.net/circuits/topics/rectifiers.pdf
+  * https://www.physicsforums.com/threads/calculating-the-dc-value-of-the-output-voltage-for-a-full-wave-rectifier.1003323/
   * https://www.electronics-tutorials.ws/diode/diode_6.html
   * https://resource.download.wjec.co.uk/vtc/2016-17/16-17_1-9/gce-electronics-book-chapter-7.pdf