Model 3604 contains three common high voltage power supplies used by scanning electron microscopes (SEM) within a compact 25 × 15 × 20 cm enclosure. The filament and bias voltages float on the accelerator voltage; all three are remotely programmable via the RS-232 data port. Connection to a SEM occurs through a conventional 3-pin Federal Standard connector. A plug-in terminal block connects 24 VDC input power, an external safety interlock, 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

Cables

PN	Image	Description
3603CBL		3-conductor, high voltage output cable (included with model 3604).