|
TSP Controllers in Indus-2
In the vacuum system of INDUS-2, ~130 TSPs are used, each with 1000 l/s pumping speed. These are powered by TSP power controllers developed in UHV section.
One controller can supply power to two TSP-s in a sequential manner. The controllers power the TSP-s in such a way that, two pulses each of one minute ‘ON’ separated by one minute ‘OFF’ are fed to the TSP. After completion of this 3 minute cycle the control is transferred to the second pump. There is a provision of adjusting the idle time interval between these pulses ranging from 1 – 999 minutes through the front panel.
The controller can power a maximum of 300 watts to filament. The Triac, which is connected in the primary of the transformer, adjusts its firing angle in a such a way that it delivers a particular preset wattage to the filament irrespective of change in filament resistance caused due to thinning. The supply takes the feedback voltage from the filament, samples the primary current and multiplies these values in a four quadrant multiplier I.C. and compares with a reference, this compared command is then given for triggering the triac. Thus the supply works in a constant power mode irrespective of change in filament resistance caused due to evaporation and consequently thinning of titanium filament.
The change-over from one pump to another pump is carried out by SSR-s connected in the primary.
The power controller has the advantage of reduced cable voltage drops for long distance of separation between the controller and the transformers for high currents as the transformers are placed just near to the TSP feedthrough-s.
This controller has got the function of degassing the Titanium filaments of the two Pumps simultaneously.
Main Parameters of the Power controller
| Mains Supply |
230volts +/- 10% , 50/60 Hz. |
| Output Power |
Variable 300 watts(maximum) (Adjustable through front panel) |
| Filament Current |
1- 60 amps.(maximum) R.M.S |
| Filament voltage |
Variable A.C. 1-5 volts (maximum) |
| Load Filament |
‘U’ hair-pin type Filament of Ti 85% + Mo 15% alloy |
| Operation Mode |
Phase angle control in the Primary of Transformer |
| Sublimation Pattern |
Two Pulses each of one minute ‘ON’ separated by a one minute ‘OFF’ period for one pump followed by a similar pattern to 2nd Pump |
| Degassing Pattern |
Series degassing of both the Filaments 45 amps.(max.) |
| Interval Time |
1-999 minute (maximum) (Adjustable through front panel) |
| Dimension |
- 480(L) X 485(b) X 130 (h) Control unit
- 210(L) X 280 (b) X 180 (h) Auxiliary unit
|
| Weight |
7 Kg |
TSP Controller
|
