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X-CapTM
Variable Capacitor (pat. pend.)
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The X-CapTM 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-CapTM is a perfect fit for the
gap between low cost air capacitors and high cost/high quality
vacuum capacitors. |
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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-CapTM 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-CapTM series includes the following 4
standard versions:
|
type |
capacitance range |
peak test voltage |
|
XC60-350 |
50 - 350 pF |
12.0 kV |
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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 kVpk |
10 kVpk |
6.0 kVpk |
2.5 kVpk |
| working voltage |
8.0 kVpk |
6.4 kVpk |
3.2 kVpk |
1.2 kVpk |
|
current at 13.56 Mhz / 25°C |
25 Arms |
25 Arms |
25 Arms |
25 Arms |
|
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-CapTM is set to Cmax.
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4. Current Curves
5. Capacitance Curve
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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.
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6. Outline
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