Example 2
Offset = 11
Pressure = 6 x 10
-8
Torr/mbar/pascal
Step 1: Calculate the log of the pressure (Log (6 x 10
-8
) = -7.2)
Step 2: Add the offset value (-7.2 + 11 = 3.8 Volts = V
pin12
)
High Voltage Monitoring (Pin 13)
Pin 13 can be used to determine if the HV is enabled. It is designed to drive a
relay or logic signals as required. When the HV is enabled, pin 13 is pulled
down to 0 V and can sink 100 mA. When the HV is disabled, pin 13 is pulled
up to +14V through a 4K7 resistor.
Output Voltage Monitoring (Pin 14)
Pin 14 is a buffered voltage output that is proportional to the HV output
voltage and can be used to monitor the HV. The scaling factor is 1 V per 1 KV
out.
8.2.
Power supplies
The following power supply pins are available on the misc. I/O connector.
These power supplies are not protected and should be used with care. Do
not attempt to power the SPCe by connecting external power supplies to
these pins.
▪
Pin 5 is connected to (approximately) –12 V.
▪
Pin 10, pin 6, and pin 15 are connected to (approximately) +12 V.
▪
Pin 7 is connected to (approximately) +5 V.
▪
Pin 3 and pin 4 are grounded.
▪
The +14 V and –14 V supplies are regulated but not calibrated - in practice
they may vary over the range 12 V to 15 V or so. Do not draw more than
50 mA from any of these supplies, and do not inject significant levels of
noise onto them.
▪
The +5 V supply may range from +4.9 V to +5.1 V. Do not draw more than
100 mA from this supply.
04/2021 - ©Gamma
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900026_F
900026_F - Back panel operation
