Model 3603 | -30 kV SEM Power Supply

  • Three outputs in compact enclosure
  •    -30 kV @ 330 uA accelerator
  •    -1 kV @ 25 uA Wehnelt
  •    5 Vdc @ 3 A floating filament
  • Input voltage 24VDC
  • USB or RS-232 remote control
  • Demo program with source code
  • Interlock input and status LED's
  • Standard federal output connector

Within this compact 25 x 12 x 20 cm enclosure are three common power supplies used by scanning electron microscopes. The filament and Wehnelt voltages are floating on the accelerator voltage. All three are remotely programmable via an RS-232 or USB data port. Connection to a SEM are through a conventional 3-pin Federal connector. A plug-in terminal block connects 24VDC input power, an external safety interlock, and an HV On status bit.


Two status lights show serial communication activity and a heartbeat lamp indicates the 3603's processor is active.


The Wehnelt voltage is derived from the bias supply.


A C-language demo program allows controlling all supplies and reports communication activity. It displays the set-point of each supply and the actual measured outputs. An internal temperature sensor is also displayed.



3603 Block Diagram


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3603 Control Panel

3603 Screen Shot

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Acceleration Voltage
Output voltage range -500 to -30,000VDC
Output current -300 uA
Output ripple & noise <300 mV
Output temperature drift 10 ppm/hour
Programmable resolution 1 ppm


Output voltage range 0 to -2000 VDC
Output current 200 uA
Programmable resolution 1 ppm
Stability 50 ppm/hour
Ripple &noise <100 mV


Output voltage 0 to 5 VDC
Output current 0 to 3 A
Output ripple < 100 mV
Output temperature drift 100 ppm/hour
Programmable resolution 1 ppm


Connector DB-9 male
Signal levels RS-232 or USB with special cable
Bit rate 57 kbits/sec
Isolation 1000 VDC max


Input power 24VDC 1.5V, 3A
Operating temperature range 10C to 35C
Interlock circuit Closed contact enables H.V.
Dimensions 254 mm x 190 mm x 114mm 10L x 7.5D x 4.5H
Weight 5 kg (11 lb)
Output connector 3-pin CA1-type Claymount
Input terminal block Requires 6-pin Phoenix Contact 1803617
Temperature monitor Inside floating H.V. section



Click to enlarge

Model 3603 Qty 1. $4,638   Qty2-9. $4,217
Claymount H.V. cable Qty 1. $300
USB to RS-232 data cable Qty 1. $30