1. Ball Aerospace Scalable Configurable Cryocooler Electronics (SCCE)
Eric Marquardt, Dave DuVal, James Simons, and Jennifer Marquardt
Ball Aerospace
2017 Cryogenic Engineering Conference
7/13/2017

2. Scalable Configurable Cryocooler Electronics
Reconfigurable and scalable design based on high heritage architecture
Goal is to have a single design for different types of cryocoolers and missions
Reduces NRE costs and provides a flight proven high performance CCE for lower cost
Architecture used on other Ball flight instruments allowing leverage from other recent programs
Hardware design based on pieces from other flight programs
80% of software has flight heritage, 20% new code is based on flight proven cryocooler control algorithms
FPGA plus CPU
FPGA handles all time critical functions and low level motor drives
CPU adds configuration control to system allowing SCCE to support many mission types with only minor changes in software
No changes to the hardware are required
2017 Cryogenic Engineering Conference
7/13/2017

3. Resolution: 1 mK (<46 K)
Design Performance
Parameter
Value
Bus Input Voltage
25-36 VDC
Motor Power
200 W
Reflected Ripple
0.4 Ap-p
Cryogenic Temperature Sensors
(2 ranges)
Range: K
Resolution: 1 mK (<46 K)
Temperature Stability
±2 mK
Operating Temperature Range
-35 to +50 °C
Parameter
Value
Drive Frequency
Range: 25 to 95 Hz
Resolution: 1 mHz
Heater Power
10 W, 2 channels
On-orbit firmware
Yes
Launch Vibration
14.1 Grms
Total Dose Radiation
100 krad
Mass
11.8 kg
Volume
29.5 x 24.9 x 21 cm
2017 Cryogenic Engineering Conference
7/13/2017

4. IRAD Control and Motor Output Board (CAMO)
CAMO Board used to drive Ball Aerospace Stirling cooler and Sunpower commercial coolers
New IRAD version will also be used with a Thales pulse tube
Test will include active vibration control
Power or Temperature control modes
Constraints also include stroke limits
Power limits can be applied in temperature control mode
Total harmonic distortion (THD) minimization can be used in all modes on voltage, force, or acceleration
2017 Cryogenic Engineering Conference
7/13/2017

5. TIRS-2 Engineering Model CCE
Control and motor output
Two high power motor drives (compressors) and two low power motor drives (displacer or damper)
Eliminates TMU position sensors
5x faster than TIRS-1
Power section is largely the TIRS-1 design
Motor power supply (MPS) requirements relaxed in areas driving the design
Redundant switch electronics (RSE) allows TMU motors and sensors to switch between two CCEs
Improves overall system reliability
2017 Cryogenic Engineering Conference
7/13/2017

6. Configurable and Scalable
Design is easily built to different screening standards supporting lower cost demonstration or high reliability TOR missions
Minor software changes allow SCCE to drive high reliability Aerospace or two Tactical coolers
Scalable input power from 25 W to 400 W or more
Motor drive frequency from 25 to 95 Hz, 1 mHz resolution
Fully redundant power, communications, and HDLC
Self Protection
Overstroke, overcurrent, high vibration, and high temperature
Diagnostic mode allows telemetry waveform capture
Up to 6 HLDC (0 required)
4x Power and 2x Software upload
Internal launch lock
2017 Cryogenic Engineering Conference
7/13/2017

7. Typical Cool Down Temperature control cool down
Demonstrates both power and stroke limiting
2017 Cryogenic Engineering Conference
7/13/2017

8. Thermal Stability Up to 6 cryogenic temperature sensors
2 ranges available
TIRS-2 resolution:
30 mK < 325 K
10 mK < 120 K
1 mK < 46 K
TMU rejection temperature quickly ramped
12 °C over 10 minutes
Insensitive to CCE temperature
±10 mK stability maintained at cold-stage during ramp
2017 Cryogenic Engineering Conference
7/13/2017

9. Back EMF Control Wide range of operating conditions
Frequency from 36 to 45 Hz
Motor powers from 50 to 200 W
Strokes from 35% to 90%
TMU rejection temperature varied from +15 to +30 °C
CCE rejection temperature varied from +15 to +40 °C
Back EMF stroke determination is stable over long periods C1 C2 D1
% Stroke Avg Error
0.05
-0.24
0.66
% Stroke
Std Dev
0.60
1.15
0.42
% Stroke Max Error
2.0
3.2
1.3
Phase (deg) Avg Error
3.40
0.55
-1.65
Phase (deg) Std Dev
1.05
1.01
1.40
Phase (deg) Max Error
5.0
2.2
3.8
2017 Cryogenic Engineering Conference
7/13/2017

10. 4 K Stirling Precooled JT CCE Model
Use two of each board
Motor power supplies share current load
Allows Stirling to draw most of the power but uses a heritage build-to-print design
Stirling Control board is slaved using redundant communications port and is driven by the JT board
Low power motors on JT used to drive the bypass valve
Provides CCE with flight heritage for a 4 K cooler
2017 Cryogenic Engineering Conference
7/13/2017

11. TIRS-2 Current Program Status
Flight boards almost finish board level testing
Conformal coat this week
Getting ready for CCE box level testing in early August
CCE integration with TMU late-August
System environmental tests start in October
Cryocooler delivery scheduled for early December
2017 Cryogenic Engineering Conference
7/13/2017