comparison: content/TeK2445_3.rst
content/TeK2445_3.rst
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| 9 :series_index: 3 | 9 :series_index: 3 |
| 10 | 10 |
| 11 | 11 |
| 12 After having mostly `destroyed the PSU of my Tek 2445 | 12 After having mostly `destroyed the PSU of my Tek 2445 |
| 13 <{filename}/TeK2445_2.rst>`_, I've decided to be a bit less foolhardy | 13 <{filename}/TeK2445_2.rst>`_, I've decided to be a bit less foolhardy |
| 14 and I've subscribed to the `yahoo Tek group`_ and discovered that such | 14 and I've subscribed to the `yahoo Tek group`_. I discovered that such |
| 15 a failure has been reported there, also after a full recap of the | 15 a failure has already been reported there, also after a full recap of |
| 16 preregulator and regulator of the power supply. | 16 the preregulator and regulator of the power supply. |
| 17 | 17 |
| 18 I found that I was not so wrong when I built my completely guessed | 18 I also found that I was not completely wrong when I built my |
| 19 LR1060. | 19 replacement LR1060. |
| 20 | 20 |
| 21 It seems to be built on a 75Ω resistor. Mine was not so far, but I | 21 It seems to be built on a 75Ω resistor. Mine was not so far, but I |
| 22 decided to rebuild one with closer specifications, so I took a new 68Ω | 22 decided to rebuild one with closer specifications, so I took a new 68Ω |
| 23 resistor and I wrapped some 34 gauge wire. The result is a bit | 23 resistor and I wrapped some 34 gauge wire around. The result is a bit |
| 24 cleaner, from: | 24 cleaner, from: |
| 25 | 25 |
| 26 .. image:: {filename}/images/tek2445/lr1060.jpg | 26 .. image:: {filename}/images/tek2445/lr1060.jpg |
| 27 :alt: first attempt of a hand made LR1060 chocke. | 27 :alt: first attempt of a hand made LR1060 chocke. |
| 28 | 28 |
| 29 to: | 29 to: |
| 30 | 30 |
| 31 .. image:: {filename}/images/tek2445/lr1060_v2.jpg | 31 .. image:: {filename}/images/tek2445/lr1060_v2.jpg |
| 32 :alt: a better hand made LR1060 chocke. | 32 :alt: a better hand made LR1060 chocke. |
| 33 | 33 |
| 34 | 34 |
| 35 But I was stuck because of my dead TR1050. Due to the lack of sucess | 35 However, I was stuck because of my dead T1050. Due to the lack of |
| 36 getting the main oscillator starts, I ended by suspecting TR1050 | 36 success getting the main oscillator starts, I end up suspecting that |
| 37 suffered when Q1050 exploded... And I was right: one of the two | 37 T1050 had suffered when Q1050 exploded... And I was right: one of the |
| 38 primary coils was short. | 38 two primary coils was short. |
| 39 | 39 |
| 40 I've found a reasonnably cheap replacement part on `QService | 40 I've found a reasonnably cheap replacement part on `QService |
| 41 Electronics`_ shop. It took a bit long to arrive (12 days from Greece | 41 Electronics`_ shop. It took a bit long to arrive (12 days from Greece |
| 42 to France, but to be honest, it seems the longest part of the transit | 42 to France, but to be honest, it seems the longest part of the transit |
| 43 was in France), but it arrived. So yesterday evening I've been able to | 43 was in France), but it arrived. So yesterday evening I've been able to |
| 44 replce it. | 44 replce it. |
| 45 | 45 |
| 46 | 46 |
| 47 The TR1050 transformer | 47 The T1050 transformer |
| 48 ====================== | 48 ===================== |
| 49 | 49 |
| 50 This transformer is a small input transformer with 4 coils around a | 50 This transformer is a small input transformer with 4 coils around a |
| 51 common ferrite core: | 51 common ferrite core: |
| 52 | 52 |
| 53 .. image:: {filename}/images/tek2445/tr1050.jpg | 53 .. image:: {filename}/images/tek2445/tr1050.jpg |
| 54 :alt: The TR1050 input transformer. | 54 :alt: The T1050 input transformer. |
| 55 | 55 |
| 56 I was not sure of the specifications of each coil, since mine as (at | 56 I was not sure of the specifications of each coil, since mine as (at |
| 57 least on one coil) defective. From the schematic, it looked natural | 57 least on one coil) defective. From the schematic, it looked natural |
| 58 that both the primary windings should have the same charactritics. So | 58 that both the primary windings should have the same charactritics. So |
| 59 when my replacement transformer arrived, I took a few measurements. | 59 when my replacement transformer arrived, I took a few measurements. |
| 60 | 60 |
| 61 The result is: | 61 The result is: |
| 62 | 62 |
| 63 .. list-table:: TR1050 windings | 63 .. list-table:: T1050 windings |
| 64 :widths: 15 10 30 | 64 :widths: 15 10 30 |
| 65 :header-rows: 1 | 65 :header-rows: 1 |
| 66 | 66 |
| 67 * - Winding | 67 * - Winding |
| 68 - R | 68 - R |
| 74 - 4.5Ω | 74 - 4.5Ω |
| 75 - 6.5mH | 75 - 6.5mH |
| 76 * - 6-7 | 76 * - 6-7 |
| 77 - 0Ω85 | 77 - 0Ω85 |
| 78 - ~ 10µH | 78 - ~ 10µH |
| 79 * - 6-7 | 79 * - 8-9 |
| 80 - 0Ω8 | 80 - 0Ω8 |
| 81 - ~ 10µH | 81 - ~ 10µH |
| 82 | 82 |
| 83 I've also quickly checked the voltage ratios using a 42kHz signal: | 83 I've also quickly checked the voltage ratios using a 42kHz signal: |
| 84 | 84 |
| 85 .. image:: {filename}/images/tek2445/tr1050_ratio_measurement.jpg | 85 .. image:: {filename}/images/tek2445/tr1050_ratio_measurement.jpg |
| 86 :alt: Measuring the turn-ratios of the TR1050 transformer. | 86 :alt: Measuring the turn-ratios of the T1050 transformer. |
| 87 | 87 |
| 88 I use CH2 of my scope to probe the signal produced by the `HP890A4 | 88 I use CH2 of my scope to probe the signal produced by the `HP890A4 |
| 89 <{filename}/hp8904a.rst>`_ linked to pins 1 and 2 (thus a primary | 89 <{filename}/hp8904a.rst>`_ linked to pins 1 and 2 (thus a primary |
| 90 winding), and CH1 on a secondary winding (pins 6-7), which resulted | 90 winding), and CH1 on a secondary winding (pins 6-7), which resulted |
| 91 in: | 91 in: |
| 92 | 92 |
| 93 .. image:: {filename}/images/tek2445/DS1Z_QuickPrint17.png | 93 .. image:: {filename}/images/tek2445/DS1Z_QuickPrint17.png |
| 94 :alt: Measuring the turn-ratios of the TR1050 transformer. | 94 :alt: Measuring the turn-ratios of the T1050 transformer. |
| 95 | 95 |
| 96 .. image:: {filename}/images/tek2445/DS1Z_QuickPrint18.png | 96 .. image:: {filename}/images/tek2445/DS1Z_QuickPrint18.png |
| 97 :alt: Measuring the turn-ratios of the TR1050 transformer. | 97 :alt: Measuring the turn-ratios of the T1050 transformer. |
| 98 | 98 |
| 99 As one can see, the turn ratio seems to be 10. Both the 2 secondary | 99 As one can see, the turn ratio seems to be 10. Both the 2 secondary |
| 100 windings (5-6 and 7-8) which provide power for the preregulator | 100 windings (6-7 and 8-9) which provide power for the preregulator |
| 101 control (U1030) and the inverter drive (U1062, U1064 and U1066), are | 101 control (U1030) and the inverter drive (U1062, U1064 and U1066), are |
| 102 identical to each other. | 102 identical to each other. |
| 103 | 103 |
| 104 Testing the new T1050 transformer | 104 Testing the new T1050 transformer |
| 105 ================================= | 105 ================================= |
| 175 - R1060 and R1070, | 175 - R1060 and R1070, |
| 176 - R1069 | 176 - R1069 |
| 177 | 177 |
| 178 So I'm done for now with this puppy. It should be completely checked, | 178 So I'm done for now with this puppy. It should be completely checked, |
| 179 but that will be another story. | 179 but that will be another story. |
| 180 | 180 |
| 181 | 181 |
| 182 Post Scriptum | 182 Post Scriptum |
| 183 ============= | 183 ============= |
| 184 | 184 |
| 185 For the fun: | 185 For the fun: |
| 186 | 186 |
| 187 .. image:: {filename}/images/tek2445/side_by_side.jpg | 187 .. image:: {filename}/images/tek2445/side_by_side.jpg |
| 188 :alt: Side-by-side: DS1054Z vs. Tek2445 | 188 :alt: Side-by-side: DS1054Z vs. Tek2445 |
| 189 | 189 |
| 190 Despite the fact the Rigol DS1054Z has an incredible number of | 190 Despite the fact the Rigol DS1054Z has an incredible number of |
| 191 features for which the Tek cannot compete, I still like this | 191 features for which the Tek cannot compete, I still like this |
| 192 old puppy a lot. Its front panel is much easier to use: every control is | 192 old puppy a lot. Its front panel is much easier to use: every control is |
| 193 directly accessible. And yet, I don't think the Rigol can measure both | 193 directly accessible. And yet, I don't think the Rigol can measure both |
| 194 the rise and fall time (with a decent precision) of a square wave: | 194 the rise and fall time (with a decent precision) of a square wave: |
