Corona Discharge Type (Voltage Application Type)

AC (Alternating Current) type

This system uses an AC power supply to alternately generate positive (+) and negative (-) ions from a single emitter needle. The AC type is suitable for static elimination at short range with no blowing air, and is used at many manufacturing sites.

High-frequency type (approx. 70 K), commercial frequency type (50/60 Hz)

What is the high-frequency type?

By applying high voltage to the emitter needle at a frequency far higher than the commercial frequency (approx. 70 kHz) and producing corona discharge, it is possible to generate large amounts of positive (+) and negative (-) ions in a balanced way, and thereby achieve a superior static elimination effect.

This enables spot static elimination impossible with other systems (commercial frequency type and DC type) particularly if used for static elimination with a tube. Furthermore, it is possible to avoid damage due to bringing the electric field generated by the emitter needle close to the semiconductor element, etc.

Comparison with commercial frequency type

The commercial frequency type uses a wire-wound transformer, and thus the equipment is typically heavy and large. The high-frequency type, in contrast, employs elements mounted on a circuit board, and thus is ultra-compact and lightweight. It is used in applications where the unit is embedded to save space in semiconductor related equipment.

		Commercial frequency type	High-frequency type
Discharge frequency		50/60Hz	20～80kHz
Applied voltage		5～8kV	2～4kV Continuous application
Charge production		Alternately generates positive and negative charges from a single emitter needle
Profile		Medium sized, heavy	Compact, lightweight
High-voltage wiring		Necessary	Power source built-in, not necessary
Static elimination performance	Long range	Good
Applied voltage	Short range	Excellent
Applied voltage	High-speed response	Not possible (possible when using multiple units)	Good
Charge transport using tube, etc.		Not possible	Excellent
Distance with charged objects		Approach not possible	Approach possible
Degree of charge equilibrium		Good (High-frequency type has high frequency, so there is little fluctuation with respect to time)

Steady DC type (Direct Current system)

This type applies positive (+) and negative (-) ions, respectively, to two emitter needles. Since high voltage is constantly applied, a large amount of ions is produced, and the system has a high static elimination speed. Emitter needle wear differs between positive (+) and negative (-) ions, and thus there is a tendency for ion balance voltage to increase as time passes.

Pulsed DC type (Pulsed Direct Current system)

This type has high static elimination speed, but since various frequency components are included, it tends to have a high level of noise.
Damage due to current leakage sometimes occurs in response to insulation fouling around the emitter needle.

HDC-AC type (Hybrid Digital Control - Alternating Current system)

This type has our unique function for ion balance adjustment through digital control of positive (+) and negative (-) ion output. This enables more advanced static elimination—for objects moving at high speed, and elimination with greater uniformity. There is little change in characteristics, even in response to emitter needle fouling, and this allows stable static elimination performance to be maintained over the long term without frequent cleaning.

PatentedHDC-AC

More advanced static elimination performance

What is HDC-AC ?