add zener to protect ADC load cell input

[hw/quantimotor] / Notebook

diff --git a/Notebook b/Notebook
index cc807cb85bc9560ea0bb36d8741754b68b6b2665..e1a0392477544d90748aef5dbcece0e72b2a2fe1 100644 (file)
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+++ b/Notebook
@@ -56,3 +56,62 @@
   Means we need multiple header pins carrying pyro voltage to get enough
   current, since the header spec is 3A per pin.  2-4 pins each for v_pyro
   on the pin 1 end, and gnd on the other end should do.
+
+- for strand burner daughter, use CUI TB003-500-P06BE 6-position 5mm pitch
+  screw terminal strip, supports 14-26 AWG wire, 10A per pin continuous,
+  DK 102-6165-ND, $1.01 q1
+
+2020.11.15
+- thinking about connectoring again.  for the base TeleStatic, we need to
+  have DC power in for battery charging, pyro output, pressure sensor, and 
+  load cell.
+
+  For battery charging, use the same powerpole and 3d-printed part we use on
+  TeleFireEight.
+
+  For pyro output, let's try a panel-mount single 3-wire AC socket:
+
+        Schurter 4300.0701, DK 486-1082-ND, $1.48 q1, needs a complex routed
+        opening, has lugs for soldering wires.  Sides squeeze to remove if
+        if needs to be replaced.  Should be easy enough to CNC mill opening.
+
+  For the pressure sensor, a 3-conductor 1/4" audio plug seems like a great
+  plan, use metal-shell Switchcraft parts.  Couple that with shielded twisted
+  pair cable.
+
+  For the load cell, we need 4 conductors plus ground, so a 5-pin XLR is an
+  economical possibility.  
+
+       male chassis IO-XLR5-M-BK-JL    DK 1937-1135-ND         4.65
+       female cable IO-XLR5-F-BK       DK 1937-1035-ND         5.25
+
+  Gary's load cells use Amphenol PC04E-10-6P, which is $64/ea from Newark!
+  Could offer to deliver him a cable with one of those on one end and what
+  we want on our end?
+
+  Cable that's 2 twisted pairs, shielded with drain wire, would suffice for
+  the load cell and could be used ignoring one pair for the pressure sensor
+  if desired.  Here's one with grey PVC jacket and foil shield:
+       Alpha M4473 SL005       DK M4473SL005-ND        51.79/100ft
+
+2021.02.09
+- Grainger carries Rust-Oleum "Industrial Choice Spray Paint in Gloss OSHA
+  Safety Purple for Masonry, Metal, Plastic, Wood", Item #6KP15, $6.60 per
+  12oz can.  The idea of test stand electronics being purple with orange
+  logo decals vs TeleFireEight being orange with purple decals might make
+  sense?
+
+2022.05.22
+- looking at firmware for v4 board.  
+
+       ads131          has driver for ADS131A0X, not quite working?
+       bdale-ui        work on teststand ui
+
+  - created new branch telestatic-v4 from master
+  - merged bdale-ui, resolving conflict in altoslib/AltosCSV.java
+  - merged ads131, resolving conflict in src/kernel/ao_data.h
+
+- improper gain setting or higher than expected mV/V on load cell can easily
+  drive INA125 output above the 5V allowed by ADC input.  adding a 5.1V, 500mW
+  zener between INA125 and ADC to clamp that and protect the ADC
+