diff -r fdee5b2913ce -r d56199d873d4 content/TeK2445_3.rst --- a/content/TeK2445_3.rst Tue Apr 19 23:15:06 2016 +0200 +++ b/content/TeK2445_3.rst Tue Apr 19 23:19:42 2016 +0200 @@ -11,31 +11,31 @@ After having mostly `destroyed the PSU of my Tek 2445 <{filename}/TeK2445_2.rst>`_, I've decided to be a bit less foolhardy -and I've subscribed to the `yahoo Tek group`_ and discovered that such -a failure has been reported there, also after a full recap of the -preregulator and regulator of the power supply. +and I've subscribed to the `yahoo Tek group`_. I discovered that such +a failure has already been reported there, also after a full recap of +the preregulator and regulator of the power supply. -I found that I was not so wrong when I built my completely guessed -LR1060. +I also found that I was not completely wrong when I built my +replacement LR1060. It seems to be built on a 75Ω resistor. Mine was not so far, but I decided to rebuild one with closer specifications, so I took a new 68Ω -resistor and I wrapped some 34 gauge wire. The result is a bit +resistor and I wrapped some 34 gauge wire around. The result is a bit cleaner, from: .. image:: {filename}/images/tek2445/lr1060.jpg :alt: first attempt of a hand made LR1060 chocke. to: - + .. image:: {filename}/images/tek2445/lr1060_v2.jpg :alt: a better hand made LR1060 chocke. - + -But I was stuck because of my dead TR1050. Due to the lack of sucess -getting the main oscillator starts, I ended by suspecting TR1050 -suffered when Q1050 exploded... And I was right: one of the two -primary coils was short. +However, I was stuck because of my dead T1050. Due to the lack of +success getting the main oscillator starts, I end up suspecting that +T1050 had suffered when Q1050 exploded... And I was right: one of the +two primary coils was short. I've found a reasonnably cheap replacement part on `QService Electronics`_ shop. It took a bit long to arrive (12 days from Greece @@ -44,14 +44,14 @@ replce it. -The TR1050 transformer -====================== +The T1050 transformer +===================== This transformer is a small input transformer with 4 coils around a common ferrite core: .. image:: {filename}/images/tek2445/tr1050.jpg - :alt: The TR1050 input transformer. + :alt: The T1050 input transformer. I was not sure of the specifications of each coil, since mine as (at least on one coil) defective. From the schematic, it looked natural @@ -60,7 +60,7 @@ The result is: -.. list-table:: TR1050 windings +.. list-table:: T1050 windings :widths: 15 10 30 :header-rows: 1 @@ -76,14 +76,14 @@ * - 6-7 - 0Ω85 - ~ 10µH - * - 6-7 + * - 8-9 - 0Ω8 - ~ 10µH I've also quickly checked the voltage ratios using a 42kHz signal: .. image:: {filename}/images/tek2445/tr1050_ratio_measurement.jpg - :alt: Measuring the turn-ratios of the TR1050 transformer. + :alt: Measuring the turn-ratios of the T1050 transformer. I use CH2 of my scope to probe the signal produced by the `HP890A4 <{filename}/hp8904a.rst>`_ linked to pins 1 and 2 (thus a primary @@ -91,13 +91,13 @@ in: .. image:: {filename}/images/tek2445/DS1Z_QuickPrint17.png - :alt: Measuring the turn-ratios of the TR1050 transformer. - + :alt: Measuring the turn-ratios of the T1050 transformer. + .. image:: {filename}/images/tek2445/DS1Z_QuickPrint18.png - :alt: Measuring the turn-ratios of the TR1050 transformer. + :alt: Measuring the turn-ratios of the T1050 transformer. As one can see, the turn ratio seems to be 10. Both the 2 secondary -windings (5-6 and 7-8) which provide power for the preregulator +windings (6-7 and 8-9) which provide power for the preregulator control (U1030) and the inverter drive (U1062, U1064 and U1066), are identical to each other. @@ -177,7 +177,7 @@ So I'm done for now with this puppy. It should be completely checked, but that will be another story. - + Post Scriptum ============= @@ -186,7 +186,7 @@ .. image:: {filename}/images/tek2445/side_by_side.jpg :alt: Side-by-side: DS1054Z vs. Tek2445 - + Despite the fact the Rigol DS1054Z has an incredible number of features for which the Tek cannot compete, I still like this old puppy a lot. Its front panel is much easier to use: every control is