Varian 929-4025 PCB HV Module Positive Preset Ion Pump Vacuum Controller SHV

Varian 929-4025 PCB HV Module Positive Preset Ion Pump Vacuum Controller SHV

The Varian 929-4025 is a printed circuit board high-voltage (HV) module designed for positive-polarity preset operation in Varian ion pump vacuum controller systems. The module integrates a high-voltage power stage — including a large toroidal inductor, filtering capacitors, and a trimmer preset (P5) — into a compact zinc-plated sheet metal chassis, allowing it to be installed as a self-contained subsystem within a Varian vacuum controller chassis. It outputs high voltage through an SHV (Safe High Voltage) coaxial connector and provides a recorder output via a DB9 female connector labeled REC OUT.

Specifications & What's Included

• Manufacturer: Varian
• Model / Part Number: 929-4025
• Type: PCB High-Voltage (HV) Module — Positive Polarity Preset
• HV Output Connector: SHV (Safe High Voltage) large-diameter coaxial connector with PTFE/ceramic center insulator
• Signal/Control Output: DB9 female connector labeled REC OUT
• System Edge Connector: AMP 532955-6, 26-pin card-edge/IDC connector (date code 9547 — week 47, 1995)
• Internal components visible: large toroidal inductor (red windings), blue film capacitor, trimmer potentiometer P5, resistors R133 and R108
• Enclosure: zinc-plated sheet metal chassis with partial open-top PCB access section
• Ground strap: green/yellow AWM ground wire with ring terminals (Tecnikabel Leini Torino, CSA rated)
• Additional ribbon cable harness with white multi-conductor connector visible internally
• Heatsink: finned aluminum heatsink on power section
• Included: module only — no mounting hardware or external cables

Applications

The Varian 929-4025 HV module is a service and replacement component for Varian ion pump vacuum controller systems, where it supplies the regulated high-voltage DC output needed to operate ion pumps in high-vacuum and ultra-high-vacuum (UHV) chambers. Ion pumps require a sustained high-voltage source (typically in the kilovolt range, positive polarity) to ionize residual gas molecules and drive them into the pump's titanium electrodes, maintaining vacuum levels in the 10⁻⁶ to 10⁻¹¹ Torr range. Varian (now part of Agilent/Leybold lineage) was a leading manufacturer of ion pump controllers used widely in semiconductor fabrication, surface science research, accelerator physics, and thin-film deposition systems through the 1980s and 1990s. The REC OUT connector allows pressure/current monitoring via an external recorder or data acquisition system. This module dates from approximately the mid-1990s based on the AMP connector date code (week 47, 1995). Replacement HV modules of this type are sought by facilities maintaining legacy Varian ion pump controllers and UHV systems.