--- 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