Zarcon Dee Grissom's Idea Page
Updated 22DEC2010
M.C.C.HPA17r16 icon Home > IdeasHPA17r16 Intro.
HPA17r16 Operating Environment.
HPA17r16 RFI filters.
The Main Amplifier Board.
HPA17r16 Vmon & sources.
HPA17r16 Tests & Afterthoughts.
M.C.C. HPA17r16 Vmon & Sources.
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Idea#017 Page 5 of 6

HPA17r16vm Voltage monitor.
Vmon in it's secret compartment
V-mon cad view
O.K. so none of my solder joints pass NASA-STD-8739.3 page 52 Figure 8-18. I was concerned about baking the components to death. I think I have the NASA-STD-8739.3 non-PTH soldering down tho.

This board was an after thought, I didn't know if I wanted this or a simple audio level bar graph display. This board is solely for monitoring the OAP+ voltage, and the left/right V-ref levels. The LEDs are green if all is good, and from amber through red if there not at optimum level. I chose this over the instant red/green to avoid any annoying non-critical blinking LEDs.

Unfortunately this board only indicates weather the voltages meet there minimum level or not. Perhaps later on I'll update this board to go from green, to cyan through blue for over voltage indication.
Dual-color LED output chart

Sense detect input schematic The difference between the L/R-Vref indicator circuits and the Power LED (Min+V) indicator circuit, is the method of providing the sense levels to the op-amp inputs. For the L/R-Vref, I only needed to drop the Vreg output just enough to trip the red led off when the L/R-vref is equal to the Vreg output. The power LED is driven by a 1/2V divider fed from OAP+, compared to the Vreg output.

LED op-amp schematic I didn't want to contaminate the sensed circuits with interference by tying a feedback loop to them, or loading them down by making them directly drive an LED. A simple differential detector will work for driving the red LED, the green LED is another matter. Here I improvised by using the voltage drop of the LED, to provide the reference for the feedback loop. The LED driving/output resistor is replaced by the two feedback loop resistors.

ESD protection diodes&capacitors I had concerns about some one walking across a carpet and touching an LED on the faceplate. In the unlikely situation that the static discharge jumps to the LED wiring instead of the faceplate, I wanted something to protect the Op-Amps. Normal equipment uses arc-gaps on the PCB to achieve this. NASA-STD-6001, hints at the possibility of a flammable atmosphere under some unfortunate situations. A simple arc-gap is a bad idea under those circumstances. Here I'm using a small capacitor to dissipate the high frequency leading-edge component of an ESD discharge pulse, and a reverse diode to clamp the lower power trialling-edge of an ESD discharge pulse. ARP5412 section 7, Fig5: Waveform1 example

Full V-Mon schematic.
HPA17r16vm Schem full
Larger Schem T.B.D.
When I first drafted out this board, I didn't think to look to see if there was a dual ESD resistant variant of the LM224KAN quad op-amp IC. I discovered my mistake, when I went to swap out the generic op-amps with actual glass for simulating the boards in an in-house variant of LASI. Well, after giving up on strictly using Texas Instruments only chips, I found three drop-in dual op-amp equivalents to the LM224KAN, including the STMicroelectronics TS522IN. The RH101#MP alternate chips, are extreme overkill for this prototype.

Sources used for the graphics;

Color scale (red & green) used to create the "Dual-color LED output" color charts, came from Tranquility Images. [External Link]

Background image in the concept art, is a southern Chile volcano eruption photo by UPI Photo/Carlos Gutierrez.

The amplifier chassis in the concept art, is the Mirage B1016G, photo by M0UKD. [External Link]

The solar flair in the RFI-Hell image is from an LLNL NIF presentation video.

Elsie charts [External Link] were screen-caped, converted to red/green/etc, and overlaid in Adobe PhotoDeluxe(tm).

Schematics were created in Paint(tm) pixel by pixel, from the original coffee-stained engineering chicken scratches.

The Stargate(tm) Alteran font used to watermark the schematics, is Anquietas by Joseph Spicer.

Simulation setup; Design setup;
RFI filters;
ELSIE v2.17,

Everything else;
TINA-TI v7.0.30.267 SF-TI,
WinVLSI v1.32,
LASI v7.0.1.1,
SPICE custome FreeBSD build
pocket calculator, 0.5mm mechanical pencil, quadrille paper,
Sir Isaac Newton's Principia Mathematica,
James Clerk Maxwell's Scientific Letters and Papers,
Various on-line grounded coplanar waveguide calculators,
88 practical OP AMP circuits you can build [TAB Books],
1988 and 2005 ARRL Hand Book,
Texas Instruments OPA2134 and BUF634 datasheets,
EagleCad v5.6.0, and intuition.

Testing Software; Testing equipment;
RightMark Audio Analyzer

dB summing calculator and dB to % converter;
pocket calculator, 0.5mm mechanical pencil, quadrille paper,
Audigy2 ZS in OSWATT,
APC Smart-UPS 1400 120V (Alterd for CRT simulation),
Dynisco UPR700 (Main bus voltage monitor),
Raytek MT MiniTemp,
Ideal 61-482 multimeter,
Canon PowerShot A560
Thanks to BatchPCB/SparkFun Electronics, for there superb workmanship with the PCBs.

<PG4 (The Main Amplifier Board)< - ^Ideas^ - >PG6 (Tests & Afterthoughts)>

Sources continued;

"Electrical Grounding Architecture: Design Guidelines for Unmanned Spacecraft", 1996, Prepared by A. Whittlesely of JPL.

"Spacecraft Power Systems Engineering", 2007, John H. Scott, NASA Lyndon B. Johnson Space Center.

"Single-supply op amp design", 1999, By Ron Mancini, Texas Instruments Incorporated.

"Op Amp Precision Design: PCB Layout Techniques", 2009, By Kumen Blake, Microchip Technology Inc.

"Reducing crosstalk of an op amp on a PCB", 1999, By Randy Stephens, Texas Instruments Incorporated.

"The PCB is a component of op amp design", 2000, By Bruce Carter, Texas Instruments Incorporated.

"Fusing Current, When Traces Melt Without a Trace", 1998, Douglas Brooks, Miller Freeman Inc. UltraCAD Design Inc.

"Current Carrying Capacity of Vias", 2003, by Doug Brooks and Dave Graves, UP Media Group inc. UltraCAD Design Inc.

"How to Gauge Traces", 2001,  by Doug Brooks and Dave Graves, UP Media Group inc. UltraCAD Design Inc.

Sources... T.B.C.

Spell-check Error from previous page... What is a "Darning Effect"!?  I've never herd of that before?

<PG4 (The Main Amplifier Board)< - ^Ideas^ - >PG6 (Tests & Afterthoughts)>

Home > IdeasHPA17r16 Intro.
HPA17r16 Operating Environment.
HPA17r16 RFI filters.
The Main Amplifier Board.
HPA17r16 Vmon & sources.
HPA17r16 Tests & Afterthoughts.

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