Ultra High Vacuum Technology Section

Prototype Design & Development

The dual channel digital power controller for SIP is designed to add some additional useful features and to overcome the problematic features of the existing design. They are:

  • Optimization of the power rating of the controller so that just enough power is delivered to the SIPs of ratings normally used in UHV systems. This has helped in reducing the weight and size of the main high voltage transformer considerably.
  • This has also enabled to have dual channel individually switchable design and offers the facility of operating 2 SIPs simultaneously. Parameter measurement is also done individually.
  • The schematic chosen is a combination of linear HV module plus microcontroller based interface and display. Linear design is retained to minimize conducted noise, whereas, apart from control, the microcontroller enables simultaneous display of parameters such as voltage, current and pressure. Also, remote status of the controller is available by means of RS232 interface.

1. Dual Channel Digital Power Controller for SIP
1. Dual Channel Digital Power Controller for SIP

The main specifications of this controller are:

Input Power230 VAC, 50 Hz
Output Power Independent outputs 2 nos.
No load voltage -6200 VDC
Current (maximum) 520 mA
Watts (maximum) 800
Protect period 5 minutes
Overcurrent trip settable 30 mA/50 mA/100 mA
Thermal protection 55º Con transformer winding surface
Process set points potential free contacts 2 nos.
Protection against open ground loop.
Display LCD 20 characters x 4 lines
Communication RS232
GUI VB.net

2. Up gradation, Development & Testing of Microcontroller based Dual Channel Titanium Sublimation Pump (TSP) Controller

2. Microcontroller based Dual Channel Titanium Sublimation Pump (TSP) Controller
2. Microcontroller based Dual Channel Titanium Sublimation Pump (TSP) Controller

  • 32 bit microcontroller
  • Output Power 1-600watts (Independent ‘Set Power’ inputs for two Pumps)
  • Filament Current 1-60A
  • Extends filament life by ~ 30% by controlling Constant Power Mode
  • Load: ‘U’hair pin type Filament (85%Ti, 15%Mo)
  • SublimationPattern:Twopulseseachofoneminute‘ON’separatedbyan‘OFF’periodfor1stpumpfollowedbyasimilarpatternfor2ndpump,orProgrammable
  • DegassingPattern:SimultaneousParalleldegassingofbothfilaments(1–60Armseach)incontinuousmode
  • ProgrammableParametersofeachPump:DelayTimer, DegassingTimer, SetPower, Overvoltage, OverCurrent, PressureThreshold
  • Local, Remote network monitoring and control via Ethernet and RS485
  • TSP Feedthrough Make : VG/ Varian

3. Upgradation and Prototype Development of Bayard-Alpert Gauge Controller

3. Prototype of Bayard-Alpert Gauge Controller
3. Prototype of Bayard-Alpert Gauge Controller

  • Pressure Measurement range 1E-03 mbar to 1E-11 mbar
  • Modular design
  • Maintenance friendly and reliable design.

4. Prototype development of Inverted Magnetron Gauge Controller

An SMPS & microcontroller based Inverted Magnetron Gauge Controller is indigenously designed & developed. The SMPS is designed on Flyback topology and is rated for 3.3 kV, 100 µA to power the gauge head. The high voltage applied is sensed and processed suitably before being sent to a microcontroller. Similarly, the ionization current measured in 6 decades is compressed through a log amp, processed suitably before being sent to the microcontroller. The micro-controller based system converts the ionization current proportional values to corresponding pressure values with the help of a look up table.Pressure, high voltage and ionization current are displayedon a LCD. Operation of gauge controller in local & remote mode is possible using keyboard interface or serial communication respectively. The controller displays under range if the pressure goes below 5E-11 mbar. It providesand displays over pressure trip at 1E-05 mbar for the protection ofHV power supply. A GUI has also been developed for data logging & remoteoperation of the gauge.
The controller has been tested successfully with Pfeiffer gauge head IKR270 and has measured pressure in the range from 1E-05 to 5E-11 mbar. The controller is expected to support Agilent make IMG gauge head also. It is housed in a half 19”, 3U, 305 mm depth unit.

4. Inverted Magnetron Gauge Controller
4. Inverted Magnetron Gauge Controller

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