1. Electric Field and Waves Instrument (EFW)
Technical Interchange Meeting
EFW Boom Electronics Board
(BEB)
Hilary Richard
University of California - Berkeley

2. BEB Block Diagram

3. BEB High Voltage Parts Study
Objective:
- Increase the High Voltage from +/-100V (THEMIS) to +/-250V
Limitation:
- Design must meet derating guidelines of GSFC PPL-21
- High voltage transistors must be selected and tested
Parts Selection:
Option 1: Increase voltage on THEMIS design.
- High voltage stage: +/- 112V
Option 2: Drop-In Qualified High Voltage parts to THEMIS design.
- High voltage stage: +/- 131V
- TO-3 package will significantly increase mass and size of BEB board
Option 3: Screen and Qualify commercial HV Transistors
- High voltage stage: +/- 168V
Option 4: Redesign BEB circuit

4. SPB Cable Characterization
Old vs. New Style Gore Cable
- Sensor Signal no longer co-ax with Floating Ground as shield
- Length increased from 22m (THEMIS) to 47m (RBSP)
Cable Characterization Tests
Set-up includes:
-THEMIS BEB and Preamp with Boom cable
- Assembled into THEMIS SPB
-Sensors in Faraday Cage with Plasma Simulator (R|C)
Test Results:
- Frequency Response
- Crosstalk Susceptibility
Reduced Immunity to switching power supply noise

5. SPB Cable Test Setup
Frequency Response Test Setup

6. SPB Cable Test Setup (cont.)
Crosstalk Susceptibility Test Setup

7. SPB Cable Test Results
AC Response of Cable and Preamp

8. SPB Cable Test Results (cont.)
Crosstalk Susceptibility of Cable and Preamp
Preliminary Results from 50Hz to 50kHz