X-Cap Vakuum Kondensator

(pat. pend.)

The X-Cap^TM is a new family of variable capacitors. It has been developed to cover the range between standard air capacitors and high performance vacuum types. Air capacitors are not only volume intensive, they are also prone to electrical and/or mechanical breakdowns being exposed to dirt and atmosphere. Regular maintenance for cleaning and lubrication is therefore required.

At higher power levels i.e. above 1000 W, the designer is usually forced to select a proven vacuum capacitor type from the CV1C-500/15 or CV05C-1000/5 family.

The X-Cap^TM is a perfect fit for the gap between low cost air capacitors and high cost/high quality vacuum capacitors.

img_xcap.GIF (19213 Byte)

It has been designed to be a reliable and cost effective variable capacitor for frequencies ranging from audio to over 30 MHz. The dielectric used is a pressurized and strongly inert gaz (SF6) which has been employed in similar applications for more than two decades.

Some highlights of X-Cap^TM features:

Identical small outlines for all capacity ranges
¼" shaft with double flat for save connection
Sturdy connection and mounting flanges on both sides with 4 x M5 threads
Net weight less than 750 grams

The X-Cap^TM series includes the following 4 standard versions:

type	capacitance range	peak test voltage
XC60-350	50 - 350 pF	12.0 kV
XC60-500	50 - 500 pF	10.0 kV
XC60-800	55 - 800 pF	6.0 kV
XC60-1500	60 - 1500 pF	2.5 kV

X-Cap^TM, technical data

1. Description:
Variable high voltage inert gas capacitor for various applications in the frequency range from audio to 30 MHz.

2. General Data:

Electrical:

parameter	XC 60 - 350	XC 60 - 500	XC 60 - 800	XC 60 - 1500
capacitance range	50 - 350 pF	50 - 500 pF	55 - 800 pF	60 - 1500 pF
test voltage	12 kV_pk	10 kV_pk	6.0 kV_pk	2.5 kV_pk
working voltage	8.0 kV_pk	6.4 kV_pk	3.2 kV_pk	1.2 kV_pk
current at 13.56 Mhz / 25°C	25 A_rms	25 A_rms	25 A_rms	25 A_rms
series inductance	31 nH	31 nH	31 nH	31 nH

Mechanical:

net weight

680 gr

695 gr

710 gr

735 gr

turns for min to max capacitance	1/2 turn (180°), endless movement
shaft diameter	6.35 mm (1/4"), double flat on top
maximum torque	0.3 N× m (= 3.06 cmkg or 2.65 inlb)
maximum body temperature
storage	-30 to + 100°C
operating	-10 to + 100°C
mounting position	any

3. Note

Warning! The unit is under pressure (3bar at 20°C). Do not attempt to open.
It is important to use on both sides of the variable electrodes all provided mounting holes/threads in order to ensure, that the imbedded brass bushings are connected to a well defined electrical potential. If the connection or mounting will not require the use of all mounting holes, an M5 screw should be inserted and tightened.
When the 90° angle between the two flats of the driving shaft points to the marks on the body, the X-Cap^TM is set to Cmax.

4. Current Curves

img_ikurven.gif (30440 Byte)

5. Capacitance Curve

A 180° rotation of the shaft will change the capacitance from Cmin to Cmax. For frequencies less than 5 MHz the capacitance will change linearly with turning angle. At higher frequencies and due to internal series inductance, the ratio from turning angle to capacitance will become non-linear.

6. Outline

img_OUTLINE.gif (5892 Byte)