Cryopump System:

Regeneration Controller:

The Regeneration Controller is the main unit of the entire cryopumping system, an 8085-based IO- and Relay controller that controls the Helium Compressor, 

Enumerated from left to right:

J1: Valve Control

  • 6: Valve V1 (NO)
  • 5: Valve V2 (NO)
  • 4: Valve V3 (NO)
  • 3: Valve V4 (NO)
  • 2: Hi Vac
  • 1: AC Common

All valve control outputs
close to 230V AC output.

J2: Heater

  • 1: 
  • 2: 
  • 3: Sieve Power

J3: Remote Valve Control

  • 6: Valve V1 (NO)
  • 5: Valve V2 (NO)
  • 4: Valve V3 (NO)
  • 3: Valve V4 (NO)
  • 2: Hi Vac
  • 1: Switched AC Common

External OR'ed control of J1
outputs. Switches 


J4: Compressor

  • 1: NC
  • 2: Compressor Remote Start
  • 3: Compressor Cooling Interlock

A simple Relay port, pins 2 & 3 
get closed to engage the
compressor. 

J5: Sensor/Remote

  • 1: TC Sig/ Ext. Set 1
  • 2: Room Temp (NO)
  • 3: Regen start (NO)
  • 4: TC Return
  • 5: TC Heater/ Ext. Set 2
  • 6: GND

Minimum operating pressure
sensing.
Either drives a TC Gauge or can
be externally controlled by
shorting pins 1 & 5 when
setpoint is met.
Shorting pin 2 to 6 (GND)
tells controller room temp
has been met. 
Shorting pin 3 to 6 for >5s
starts a regeneration cycle.

J6: Test

  • 1: ?
  • 2: ?
  • 3: ?
  • 4: ?
  • 5: ?
  • 6: ?
  • 7: ?
  • 8: ?
  • 9: ?

AC Power

  • 230V 1Ph

Temperature Monitor:

The Temperature Monitor reads room and cryopump cold head temperature, compares with setpoints and controls 3 relay outputs from these. 

Enumerated from left to right:

J1: Room Temp.

  • 3: NC
  • 2: GND
  • 1: Room Temp. (NO)

Relay output, closure signaling cryopump has reached room temperature. 

J2: Low Set.

  • 3: NC
  • 2: Common
  • 1: Low Temp. (NO)

Relay output, closure signaling cryopump low setpoint has been met. 

J3: High Set.

  • 3: NC
  • 2: Common
  • 1: HighTemp. (NO)

Relay output, closure signaling regeneration heating temperature has been met. 

J4: Digital Out

  • 1: NC
  • 2: Compressor Remote Start
  • 3: Compressor Cooling Switch

A simple Relay port, pins 2 & 3 
get closed to engage the
compressor. 

J5: Sensor

  • 1: ?
  • 2: ?
  • 3: ?
  • 4: ?

Cryopump cold head temperature sensor. Possibly diode/RTD/Hybrid based. 

AC Power

  • 230V 1Ph

Helium Compressor Module & Cable Harness:

The cooling system itself, a 2-stage Gifford-McMahon cooler (Wikipedia Article). The helium cooler is a high pressure, low-leakage scroll pump compressing helium between 12.5 Bar and 28 Bar, creating a overpressure in the exit line and vacuum in the return line. It also powers the motor for the 2-stage GM-expansion responsible for the cooling. 

Enumerated from left to right:

Circular Connector:
Compressor Module

  • A: ~Lr (AC 3Phase)
  • B: ~Ln (AC 3Phase)
  • C: GND (PE)
  • D: Compressor Cooling Interlock
  • E: Compressor Remote Common
  • F: Compressor Remote Start
  • G: NC

Relay output, closure signaling cryopump has reached room temperature. 
While E has a Common-function, it is not used in the rack. Interlock and rack are connected in series

Compressor Remote Start

  • A: Compressor Remote Common
  • B: NC
  • C: Compressor Remote Start

Relay Input, shorting pins 3 & 1 turns compressor on. 

Valve Control

  • A: Compressor Cooling Interlock
  • B: NC
  • C: Compressor Remote Common
  • D: NC

Interlock membrane pressure switch, won't turn on unless water pressure and flow rate are at acceptable rates. Connected in series with rack for compressor remote start. 

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