Difference between revisions of "DRIVE50"

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=== Automated Test Software Method ===
 
=== Automated Test Software Method ===
  
* [https://github.com/land-boards/QT-Py/blob/main/CircuitPython/lbcards/PulseGen/PulseGen_DRIVE50_Test.py PulseGen_DRIVE50_Test.py] - Tests PulseGen and DRIVE50 cards
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[[File:PulseGen_TestStation_P18373-720px.jpg]]
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==== Setup ====
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* [[QTPy49]]
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* [[QT_Py_(RP2040_based)]]
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** Analog cable
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** GVS Cable to A1
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** Analog in (BNC) to A0 on [[QTPy49]]
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* [[MyMenu]]
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* Power card options
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** Connect USB-C to the [[QT_Py_(RP2040_based)]] or
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** Power from 9-12V to DC jack
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* Cables
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** USB-C (power option)
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** Power cable to UUT
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* Terminator - dependent on build option
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** 50 Ohms
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** 75 Ohms
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* Unit Under Test (UUT)
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* [https://github.com/land-boards/QT-Py/blob/main/CircuitPython/lbcards/PulseGen/PulseGen_DRIVE50_Test.py PulseGen_DRIVE50_Test.py] - Test software for PulseGen and DRIVE50 cards
 
** Stored as code.py on [[QT_Py_(RP2040_based)]] to auto-run
 
** Stored as code.py on [[QT_Py_(RP2040_based)]] to auto-run
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==== Procedure ====
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* Connect 3 pin power cable to card
 
* Connect 3 pin power cable to card
 
* Connect BNC T to output of card
 
* Connect BNC T to output of card

Revision as of 16:15, 30 July 2022

DRIVE50 P1080480-720PX.jpg

50 Ohm Driver Card

  • "TTL" Level Line driver
  • 50 or 75 Ohm output impedance
  • BNC or SMA output connector
  • 10K pull-up on input
  • Card is non-inverting
  • 1.5V-5.5V power
    • Typically 3.3V or 5V
  • 3-pin right angle 0.1" pitch input connector
  • (4) 4-40 mounting holes

Driver

  • 5x paralleled 74AC14 drivers
    • 24mA per pin max current output
      • Symmetric high-low drive levels
    • Short-circuit proof
      • 5V, 250 Ohms to ground is 20 mA (pins are rated for 24 mA
  • Card input has single buffer stage
  • Schmitt Trigger Input
  • 3.3V, 250 Ohm resistors (/5) for 50 Ohm output
    • Normal output = 10 mA per pin

Test

  • Manual or Automated test methods

Manual Test Method

  • Supply Vcc 3.3V to 5V and ground
  • Input is pulled up to Vcc
  • Measure output with BNC T
    • Should be 1/2 of Vcc with 50 Ohm terminator
    • Should be Vcc without terminator

Automated Test Software Method

PulseGen TestStation P18373-720px.jpg

Setup

Procedure

  • Connect 3 pin power cable to card
  • Connect BNC T to output of card
  • Connect BNC female from tester to BNC T male
  • Install 50 terminator to other side of BNC T
  • Connect USB C cable
  • Display will show
PulseGen/DRIVE50 V1.1
50 Ohm card
Set/Got Low
Term High = OK
  • All 3 LEDs are on

Mechanicals

DRIVE50 MECHS REV1.PNG

Assembly Sheet