High Voltage Capacitors — Film, Ceramic & Specialty HV Types
Source high voltage capacitors from Specap including film types rated up to 100kV, ceramic disc and doorknob capacitors, pulse discharge types, and oil-filled power capacitors for industrial, medical, and research applications.
Film HV Capacitors (up to 100kV)
Polypropylene and polyester film capacitors rated for high voltage applications in power supplies, lasers, and pulse-forming networks.
Ceramic Disc & Doorknob
High voltage ceramic capacitors in disc and doorknob form factors for RF, broadcast, and industrial heating applications.
Pulse Discharge Types
Specialized pulse capacitors for energy storage, Marx generators, and pulsed power systems with high dV/dt ratings.
Custom HV Solutions
Application-specific sourcing for custom voltage ratings, capacitance values, and specialized HV capacitor configurations.
Types of High Voltage Capacitors
High voltage capacitors are designed to operate at voltages from 1kV to over 100kV. The dielectric material, construction method, and encapsulation determine which applications each type is suited for. Understanding these differences is critical for safe, reliable system design.
| Type | Voltage Range | Dielectric | Key Characteristics | Common Applications |
|---|---|---|---|---|
| Film (MKP/MFP) | 1kV – 100kV | Polypropylene | Low loss, self-healing, high dV/dt | Power supplies, inverters, snubber circuits |
| Ceramic Disc | 1kV – 15kV | Class 1/2 ceramic | Low capacitance, high frequency | RF power, coupling, bypass |
| Doorknob | 5kV – 40kV | High-K ceramic | High current, compact form factor | RF transmitters, induction heating, broadcast |
| Pulse Discharge | 1kV – 100kV+ | Film or paper/oil | Very high peak current, fast rise time | Marx generators, lasers, pulsed power |
| Oil-Filled | 1kV – 35kV | Paper/film + oil | High energy density, self-healing | Utility PFC, transformer coupling, HV filters |
High Voltage Capacitor Selection Criteria
Selecting the right HV capacitor requires evaluating several parameters beyond basic capacitance and voltage:
- Voltage derating — Always derate HV capacitors by 20-30% below their maximum rated voltage. A capacitor rated at 10kV should be operated at 7-8kV maximum for reliable long-term performance. See our derating guide for detailed recommendations.
- dV/dt rating — In pulse and switching applications, the rate of voltage change across the capacitor can be more destructive than the peak voltage itself. Film capacitors with self-healing properties handle high dV/dt better than ceramic types.
- Peak current capability — Pulse discharge applications may demand thousands of amps in microseconds. The capacitor's ESR, lead inductance, and internal construction must support these currents without failure.
- Creepage and clearance — At voltages above 5kV, the physical spacing between terminals and the surface path along the capacitor body becomes critical. Doorknob capacitors with porcelain insulators provide excellent creepage characteristics.
- Temperature coefficient — HV ceramic capacitors (especially Class 2 types like Y5V) can lose 50-80% of their capacitance at temperature extremes. Class 1 (C0G/NP0) types maintain stability but at lower capacitance values.
- Energy storage — For pulse power applications, the energy stored (E = ½CV²) and the discharge efficiency matter more than capacitance alone. Use our energy storage calculator to size your capacitor bank.
Industries That Use High Voltage Capacitors
- Medical equipment — X-ray generators, defibrillators, MRI systems, and medical lasers all require precision HV capacitors with strict safety and reliability requirements. See our medical capacitor solutions.
- Broadcast & telecommunications — RF transmitters use doorknob and disc capacitors in tank circuits and impedance matching networks operating at frequencies from 100kHz to 100MHz.
- Industrial heating — Induction heating systems and dielectric heating equipment use HV capacitors in resonant circuits operating at 10-500kHz with voltages from 1kV to 20kV.
- Power utilities — High voltage capacitor banks provide power factor correction, harmonic filtering, and voltage regulation at the transmission and distribution level.
- Research & defense — Pulsed power systems, particle accelerators, electromagnetic launchers, and plasma physics experiments require specialized pulse capacitors with extreme energy storage and discharge capabilities.
- Renewable energy — Solar inverters and wind turbine converters use HV film capacitors in DC link and filtering stages operating at 600-1500V DC.
Frequently Asked Questions
What types of high voltage capacitors do you sell?
We supply high voltage film capacitors (up to 100kV), ceramic disc and doorknob capacitors, pulse discharge capacitors, oil-filled power capacitors, and specialty HV types for industrial, medical, and research applications.
What voltage ratings are available for high voltage capacitors?
Our high voltage capacitor inventory covers ratings from 1kV to over 100kV depending on the type. Film capacitors are available up to 100kV, ceramic doorknob types to 40kV, and pulse capacitors for specialized high-energy applications.
Can you source custom high voltage capacitor solutions?
Yes. We work with leading HV capacitor manufacturers to source custom voltage ratings, capacitance values, and form factors for specialized applications including pulse power, medical equipment, and research systems.
What safety considerations apply to high voltage capacitors?
High voltage capacitors require proper voltage derating (typically 70-80% of rated voltage), appropriate discharge procedures, and insulation considerations. We recommend reviewing our voltage derating guide and consulting with our technical team for application-specific guidance.
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