What is the difference between single-disc and double-disc screw terminal capacitors?

HVC Capacitor offers both single-disc and double-disc configurations for its HVCT8G screw terminal high voltage ceramic capacitor line — each architecture optimized for different capacitance ranges, power handling requirements, and physical space constraints.

Design Parameter

Single-Disc (HVCT8G-S)

Double-Disc (HVCT8G-D)

Engineering Implication

|------------------|------------------------|------------------------|-------------------------|

Physical Structure	One ceramic disc element	Two ceramic discs stacked in series	Double-disc doubles voltage rating
Capacitance Range	280pF – 4,700pF	100pF – 2,200pF	Single-disc = higher C per volume
Voltage Rating	10kV – 80kV	20kV – 150kV	Double-disc = higher V capability
ESR (Typical @ 1kHz)	0.05Ω – 0.15Ω	0.08Ω – 0.20Ω	Slightly higher ESR for double
ESL (Typical)	3nH – 8nH	5nH – 12nH	Higher ESL due to stacked structure
dV/dt Capability	Up to 50 kV/μs	Up to 30 kV/μs	Single-disc better for fast pulses
Thermal Dissipation	Better (single element)	Good (two elements share heat)	Single-disc runs cooler at high PRF
Footprint Diameter	Ø25mm – Ø50mm	Ø30mm – Ø60mm	Double-disc needs more PCB area

Application Priority

Recommended Configuration

Rationale

|--------------------|--------------------------|-----------|

Maximum capacitance density	Single-Disc	More C per unit volume
Ultra-high voltage (>80kV)	Double-Disc only	Only double-disc reaches >80kV
High dV/dt pulse circuits	Single-Disc	Lower ESL enables faster edges
Space-constrained designs	Single-Disc	Smaller footprint possible
Extreme reliability / redundancy	Double-Disc	Series structure provides graceful degradation margin

* CO₂ Laser PFN Primary Tank: Typically uses single-disc HVCT8G-S (high C, moderate V, high dV/dt)

* Medical CT Scanner HV Tank: Often specifies double-disc HVCT8G-D (very high V, moderate C, safety-critical)

* Industrial X-Ray Generator: Mixed — lower-voltage stages use single-disc, final output stage uses double-disc

* Electrostatic Precipitator Filter Bank: Usually double-disc for extended voltage headroom and longevity

single disc vs double disc capacitor, screw terminal capacitor configuration, HVCT8G single double disc, high voltage capacitor architecture, dV/dt capacitor selection

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{ "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [{ "@type": "Question", "name": "What is the difference between single-disc and double-disc screw terminal capacitors?", "acceptedAnswer": { "@type": "Answer", "text": "HVCT8G available in single-disc(S: 280pF-4.7nF, 10-80kV, better dV/dt) and double-disc(D: 100pF-2.2nF, 20-150kV, higher voltage). Selection: max capacitance→S, ultra-high-V>80kV→D only, high dV/dt pulse→S, space-constrained→S, extreme reliability→D. Laser PFN→S, CT scanner→D, X-ray→mixed, ESP filter→D." } }] }

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