# Presentation: 143737

##  TF Joint Voltage DropInstrumentation

- Robert Marsala
-  (609) 243-2507
- Hans Schneider
- (609) 243-2017
- Engineering Operations
- August 7, 2003

- TF_JOINT_Final_Design_Review.ppt

## Voltage Drop Measurement Plan

- Instrumentation Must be Capable of the Following
- Maintenance Testing
- Inject up to +/-220A into TF Coil and Measure the Voltage Drop at Every Joint
- Operational Testing
- Measure the Voltage Drop at Every TF Joint During an Actual Shot at Up to 72KA
- Common
- Computation or Resistance, Trending, Alarms, Warnings

## System Block Diagram

- EPICS

- R=V/I (at 72kA or 200A)

- Agilent 6671A
- 220A @ 8V

- 1N4047
- 275A
- 200V

- Polarity
- Switching
- Relay

- Transorbs
- 450J 50kA
- 340V
- 200A

- 1 Ohm
- 275W

- Shunt
- 40mV
- @ 200A

- CAMAC
- CRATE
- 96
- Channels
- ADC

- #24AWG Two Twisted Pair
- Teflon (1500V Between Conductors)
- Tefzel Outer Insulation
- (Spark Test to 10kV)

- x 72

- x TBD

- Instrumentation Rack

- Manual Control

- Gain
-   72kA
-      or
-        200A

- Two Twisted Pair Per Flag

- Shunt Voltage

- TF Power Supply
- Halmar Current

- Disconnect
- Switch

**Notes:**
Hardware Only estimate (with spares)
Joint Resistance – 72,000 Amps
All 72 Joints = $21,000 (Includes Wiring and Chassis Top & Bottom)

Joint Resistance – 200 Amps
All 72 Joints = $1,300 (In addition to 72,000 Amp configuration)
Note: Insitu “COMBO” Test System Saves $5,500  as opposed to separate Maintenance and Commissioning Systems.

Strain Gauges
24 Locations (12 Top, 12 Bottom of Machine)
$17,200 (In addition to 72,000 Amp configuration)

Displacement
16 Locations = $13,600 (Independent from 72,000A configuration, includes Sensors, Cabling & 6031E or equivalent Data Acquisition Board)

PCI Digitizer
Complete $13,000

GPIB Extenders
With Fiber Optic Cable (new) $3,000 (could substitute discontinued, used HP37204A’s for a $1,500 savings)
Grand Total: $69,100

## TF Joint Voltage Measurement Components

- 2 Voltage Probes on Each TF Joint
- Cables from all Probes (144) to Racks
- Instrumentation Consisting of
- Quick Disconnect Panel
- Isolated Programmable Gain Amplifier
- CAMAC Transient Digitizer
- 200 A Source Hardware and Switch

## TF Flag Joint Voltage Probes

- Two Probes per Joint
- 144 Potential Data Points

- Two Coax Probes
- To Measure
- Voltage Drop

## Probe Detail

- Probe Terminated in a SMB Connector Near Flag

## Cable

- Janor Wire & Cable Corp
- 2 Twisted Pairs per Cable with Overall Jacket
- One TP for Each of the Two Probes on a Joint
- #24 Conductors
- ETFE Insulation
- 10KV Isolation from Conductor to Outer Jacket
- Terminations
- Flag End:  SMB Mating Cable Spliced to Cable
- Rack End:  4 Pin Locking Tripeg Molex Connector

## Instrumentation

- Located in Two Racks on Midplane Level
- Consists of
- Mother Boards (6)
- Quick Disconnect (12)
- Programmable Gain Isolation Amplifier (72)
- CAMAC Crate with Transient Digitizers
- Power Supplies
- 200A Source and Control

## Quick Disconnect Modules

- Channels Can be Quickly Disconnected from the Amplifiers
- 6 Channels (12 Probes) Serviced by each of 12 Disconnects
- Uses Properly Spaced Banana Jacks on Mother Board and Banana Plugs on Disconnect Module

## Quick Disconnect

- Banana
- Plugs

- Mother
- Board

- Disconnect
- Board

- BananaJacks

## Programmable Gain Isolation Amplifier

- Amplifies and Isolates Voltage Across Joint
- 12 Boards per Mother Board, 6 Mother Boards = 72 Boards
- 5000V Isolation between Input and Output
- Two Gain Stages (Each having a Gain of 1, 10, 100 or 1k) followed by Unity Gain Isolation Amplifier
- Overall Gain from 1 to 1 Million Controlled by Two Rotary Switches on Control Panel
- Nominal Gain:  100 for 72kA, 10,000 or 100,000 for 200A
- Board Designed to Measure Voltages from Both Probes of a  Joint, but only Parts for One Probe are Installed (Cost)

## Summary

- 2 Voltage Probes on Each TF Joint
- Cables from all Probes (144) to Instrumentation Racks
- Quick Disconnects Provided to Open Probe to Amplifier Connections
- Capable of 72kA Operation or 200A Maintenance Operation
- One Probe from Each Joint is Monitored
- Isolation to 5000V
- CAMAC Data Acquisition
- EPICS Used for Calculations, Trending, Alarms and Warnings

## Resistance Measurement System Benefits 

- All 72 Joints Monitored at 200A and 72kA
- Manual 200A & Automated 72kA Measurements
- Expandable & Upgradeable
- Measure All 144 Probes & Automate 200A Measurements
- CAMAC Digitizer Upgraded to PCI Digitizer
- Addition of Strain Measurements
- Design Signal Conditioning/Amp/Iso Board
- Least Cost (M&S) and Effort (Manweeks) System
- Combo Amp/Iso Board Designed and Being Tested
- CAMAC Crate and 908 Digitizers Available

## Mother Board

- Each Mother Board Services 12 Joints (24 Probes)
- 6 Mother Boards Mounted in Rack
- 3 Accessible from Front of Rack and 3 from Rear
- Expansion to 8 Mother Boards is Provided (Strain or Displacement)
- Only One Probe from a Joint is Actively Monitored
- Capable of Expansion to Actively Monitor Both Probes
- Active Probe can be Selected by Plugging Cable Connector into a Second Connector on the Mother Board

## Mother Board

## Iso-Amplifier Schematic

## CAMAC Crate

- CAMAC Crate with 3-908 Transient Digitizers Used to Store Voltage and Current Data
- EPICS Used to Calculate Resistance and for Trending/Status/Alarms
- Memory/Sample Rate TBD

## Programmable Gain IsolationAmplifier Layout

- Input Connector

- Input Resistors

- PG Amps

- Isolation Amp

- Buffer

- Opto Couplers

- DC/DC Conv

- Output and Control Connector

- 5000V Barrier

## Power Supplies

- All Programmable Gain Isolation Amplifiers Powered by +/- 15V Linear Supplies (2) for Ground Referenced Output and +24V Linear Supplies (2) for DC/DC Converters

## 200A Supply and Control

- Supply
- Agilent 6671A
- 220A @ 8V
-  Control and Protection
- Current Programmed via Pot on Control Panel
- Polarity Switching Relays Controlled from Control Panel
- Interlock to Prevent Switching of Polarity while Current is Flowing in TF Coil
- Protection Incase of Open Circuit
- Interlocked Switch to Apply 200A to TF Bus