Model 3604 contains one to five common high voltage power supplies used by scanning electron microscopes (SEM) within a 19" rack-mounted enclosure. The filament and bias voltages float on the accelerator voltage; all three are remotely programmable via the USB-B data port. Connection to a SEM occurs through 3 flying leads. A plug-in terminal block connects AC or 24 VDC input power, and a ″HV On″ status bit.

Functional block diagram

Two status lights show serial communication activity and a heartbeat lamp indicates that the processor of the 3604 is active.

The bias voltage is derived from the accelerator supply and controlled by an electronically programmable Wehnelt resistor.

Software

A Legacy C-language demo program allows control over all supplies and reports communication activity. It displays the set-point of each supply and the actual measured outputs. Internal temperatures of the individual power supplies are also displayed.

A newer Visual Basic Demo program is also available with the same functionality as the Legacy software. It works with new units that come pre-configured with configuration settings embedded within the unit itself. No external .ini configuration files are needed.

Demo program