Kingtronics Blog

Surge arresters are designed to protect electrical equipment from damaging effects of spikes and transients caused by lightning, utility switching, isolation arcing, electrical motor cycling, or any other sudden change in electrical power flow on incoming AC power lines. 

And these devices also provide ideal protection for outdoor lighting and pole lamps, panel boards, workshops, refrigeration systems, electric motors and controls, heat pumps and air conditioning equipment, and many other electrical devices. 
More information about our products: http://www.kingtronics.com/surge-arresters/

The Ceramic gas discharge tube can be used in all places that have over-voltages.We should decide the parameter of the GDTs base on the need of the actual circuit and then select the suitable GDTs,
otherwise,we may get the reverse result.The following is the notice when using  the Ceramic gas discharge tubes:

1)Must avoid affecting the normal operation of circuit when using the Ceramic gas discharge tube.
2)Confirm the maximum peak voltage that the circuit can bear,make sure that the GDT's impulse spark-over voltage must be lower than it
3)Based on the possible impulse current energy to select the necessary impulse discharge current volume of  the Ceramic gas discharge tube
4)When the over-voltage disappears, the GDTs must extinguish rapidly to avoid affecting the normal operation of the circuit.
5)If over-voltage lasts significantly longer, GDT's discharge may continue for an extended period and generate significant thermal energy
6)Select suitable volume of  the Ceramic gas discharge tube according to the applied space.

 Over-voltage transients often occur in electric circuit. Such abnormal voltages are often caused by lightning strikes,atmospheric lightning discharges,accidental contact between power and communications lines,unexpected rise in the supply voltages of the installation as a result of misoperation,and appearance of voltage higher than normal during switching operations.The over-voltage transients,if not properly taken care of, not only cause damage to delicate components such as semiconductors,ICs and others in the equipment,but also are highly dangerous to personnel.Thus,protection against over voltages is necessary for high reliability and long life of general electronic equipment.The better protection selection for the over-voltage transients is ceramic gas discharge tubes.

The Ceramic gas discharge tube is a switching component which is controlled by voltage.It is used to be parallel connected between the line and line of equipment,or between the line and the ground(show as the bottom figures).If the over-voltage doesn't reach GDT's action voltage,the ceramic gas discharge tube will be in high resistance status.If the over-voltage is higher than GDT's action voltage,the GDT's internal gap will then break down.The Ceramic gas discharge tube is almost short-circuit at this time and limits the over-voltage to almost 0 volt within 50ns,so the surge current can be led to ground rapidly and then the equipment can be protected safely.When the over-voltage disappears, the Ceramic gas discharge tube will extinguish and return to high insulation status,preparing for the next action.  

DC spark-over voltage：The voltage at which the ceramic gas discharge tube sparks over with gradully increasing DC voltage.

Impulse spark-over voltage: The highest voltage at which the ceramic gas discharge tube sparks over with given ware-shape at a rise speed 1000V/μs, and it is also called as “pulse voltage".

Holdover voltages : The maximum DC voltage across the terminals of a ceramic gas discharge tube under which it may be expected to clear and to return to the high impedance state after the passage of a surge, under specified circuit conditions.

Alternating discharge current : The r.m.s. value of an approximately sinusoidal alternating current passing through the ceramic gas discharge tube.

Impulse discharge current: The peak value of the impulse current passing through the ceramic gas discharge tube, and it is also called as pulse discharge current or surge discharge current, including 10/1000μs long-wave discharge current and 8/20μs short-wave discharge current.

Insulation resistance：DC resistance of the gas discharge tube under specified conditions. Test voltage must be lower than DC spark-over voltage.

Inter-electrode capacitance : The capacitance between any two electrodes in the gas discharge tube. Its value is mainly determined by the size of electrode and distance between electrodes. In addition, the capacitance is also related to the lead wire length, spacing and dielectric in the ceramic gas discharge tube.

Gas discharge tube generally uses ceramic as its packing housing. The discharge tube is filled with inert gases with stable electrical characteristics and provided with structure of two or three electrodes .When certain voltage is applied to inter-electrode of discharge tube, nonuniform electric field will be produced. Gases begin to ionize under the effect of electric field. When applied voltage reaches inter-electrode field intensity and exceeds the insulation strength of inert gas, the electric arc will be produced between the electrodes to ionize gas, and the negative resistance characteristic will be produced. 

Thus, the insulation state will be turned into conductive state immediately. i.e. when electric field strength exceeds the puncture strength of gas, the gap discharge will be caused, and inter-electrode voltage will be limited. That is to say, when there is no surge, it will be in the state of open circuit. When surge occurs, the electrode plates in the discharge tube close and connect，allowing harmful current to be discharged via ground wire or circuit loop. 

When surge disappears, the discharge tube restores to the state of high impedance rapidly, and the circuit continues to work properly.

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters.
Including 2 Surge Arresters 8*6mm, 2 Surge Arresters SMD4532,2 Surge Arresters SMD5042,3 Surge Arresters 8*10mm,3 Surge Arresters SMD5076

Today we recommend our SKT-3R-SMD5076 SMD Gas Discharge Tube to you

Key Characteristics 
● DC Breakdown Voltage (@100V/S) : 75~1000V
● Tolerance of DCBV : ±20%
● Impulse discharge current (8/20 μs) : Max. 5KA 
● Alternating discharge current (@50Hz) (A): Max. 5 A 
● Insulation resistance min.: 1 GΩ 
● Electrode Capacitance (@1MHz) (pF) min: ≤1.5pF

Features
●Size Designφ5 × 5 × 7.6mm
●Fast Response and Long Service Life
● Excellent Current Handing Capability 5,000A @ 8/20μs
● Stable performance over life
● Very low capacitance and Insertion Loss
● High insulation resistance 
●Reliable to Protect Electrostatic Surge
●Moisture sensitivity level: Level 1
● RoHS-compatible

Applications
●Telephone/fax/modem protection 
●Signal line protection
●Protective circuits
●3-point protection
●5- point protection
●Cable TV/coaxial cable protection
●AC line protection

Kindly please check more items and datasheet from below links:
Product link:  http://www.kingtronics.com/pdf/3-Surge-Arresters-SMD5076.pdf

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters.
Including 2 Surge Arresters 8*6mm, 2 Surge Arresters SMD4532,2 Surge Arresters SMD5042,3 Surge Arresters 8*10mm,3 Surge Arresters SMD5076

Today we recommend our SKT-3R Radial Surge Arresters Gas Discharge Tube to you

Key Characteristics 
● DC Breakdown Voltage (@100V/S) : 75~1000V
● Tolerance of DCBV : ±20%
● Impulse discharge current (8/20 μs) : Max. 10KA 
● Alternating discharge current (@50Hz) (A) : Max. 10 A 
● Insulation resistance min.: 1 GΩ 
● Electrode Capacitance (@1MHz) (pF) min: ≤1.5pF

Features
●Size Designφ8 × 10mm
●Fast Response and Long Service Life
● Excellent Current Handing Capability 5,000A @ 8/20μs
● Stable performance over life
● Very low capacitance and Insertion Loss
● High insulation resistance 
●Reliable to Protect Electrostatic Surge
●Moisture sensitivity level: Level 1
● RoHS-compatible

Applications
●Telephone/fax/modem protection 
●Signal line protection
●Protective circuits
●3-point protection
●5- point protection
●Cable TV/coaxial cable protection
●AC line protection

Kindly please check more items and datasheet from below links:
Product link:  http://www.kingtronics.com/pdf/3-Surge-Arresters.pdf

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters.
Including 2 Surge Arresters 8*6mm, 2 Surge Arresters SMD4532,2 Surge Arresters SMD5042,3 Surge Arresters 8*10mm,3 Surge Arresters SMD5076

Today we recommend our SKT-2R-SMD5042 Square SMD Gas Discharge Tube to you

Key Characteristics 
● DC Breakdown Voltage (@100V/S) : 75~800V
● Tolerance of DCBV : ±20%
● Impulse discharge current (8/20 μs) : Max. 5KA 
● Alternating discharge current (@50Hz) (A) : Max. 2 A 
● Insulation resistance min.: 1 GΩ 
● Electrode Capacitance (@1MHz) (pF) min: ≤1pF

Features
●Size Design 5 × 5 × 4.2mm
●Fast Response and Long Service Life
● Excellent Current Handing Capability 5,000A @ 8/20μs
● Stable performance over life
● Very low capacitance and Insertion Loss
● High insulation resistance 
●Reliable to Protect Electrostatic Surge
●Moisture sensitivity level: Level 1
● RoHS-compatible

Applications
●Telephone/fax/modem protection 
●Signal line protection
●Protective circuits
●3-point protection
●5- point protection
●Cable TV/coaxial cable protection
●AC line protection

Kindly please check more items and datasheet from below links:
Product link:  http://www.kingtronics.com/pdf/2-Surge-Arresters-SMD5042.pdf

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters.
Including 2 Surge Arresters 8*6mm, 2 Surge Arresters SMD4532,2 Surge Arresters SMD5042,3 Surge Arresters 8*10mm,3 Surge Arresters SMD5076

Today we recommend our SKT-2R-SMD4532 SMD Gas Discharge Tube to you

Key Characteristics 
● DC Breakdown Voltage (@100V/S) : 75~800V
● Tolerance of DCBV : ±20%
● Impulse discharge current (8/20 μs) : Max. 2KA 
● Alternating discharge current (@50Hz) (A) : Max. 2 A 
● Insulation resistance min.: 1 GΩ 
● Electrode Capacitance (@1MHz) (pF) min: ≤1pF

Features
●Size Design 4.5 × 3.2 × 2.7mm
●Fast Response and Long Service Life
● Excellent Current Handing Capability 5,000A @ 8/20μs
● Stable performance over life
● Very low capacitance and Insertion Loss
● High insulation resistance 
●Reliable to Protect Electrostatic Surge
●Moisture sensitivity level: Level 1
● RoHS-compatible

Applications
●Telephone/fax/modem protection 
●Signal line protection
●Protective circuits
●3-point protection
●5- point protection
●Cable TV/coaxial cable protection
●AC line protection

Kindly please check more items and datasheet from below links:
Product link:  http://www.kingtronics.com/pdf/2-Surge-Arresters-SMD4532.pdf

Kingtronics sell 2-Electrode arresters and 3-Electrode arresters.
Including 2 Surge Arresters 8*6mm, 2 Surge Arresters SMD4532,2 Surge Arresters SMD5042,3 Surge Arresters 8*10mm,3 Surge Arresters SMD5076

Today we recommend our SKT-2R Axial Surge Arresters Gas Discharge Tube to you.

Key Characteristics 
● DC Breakdown Voltage (@100V/S) : 75~1000V
● Tolerance of DCBV : ±20%
● Impulse discharge current (8/20 μs): Max. 10KA 
● Alternating discharge current (@50Hz) (A): Max. 10 A 
● Insulation resistance min.: 1 GΩ 
● Electrode Capacitance (@1MHz) (pF) min: ≤1.5pF

Features
●Size Designφ8x6mm
●Fast Response and Long Service Life
● Excellent Current Handing Capability 5,000A @ 8/20μs
● Stable performance over life
● Very low capacitance and Insertion Loss
● High insulation resistance 
●Reliable to Protect Electrostatic Surge
●Moisture sensitivity level: Level 1
● RoHS-compatible

Applications
●Telephone/fax/modem protection 
●Signal line protection
●Protective circuits
●3-point protection
●5- point protection
●Cable TV/coaxial cable protection
●AC line protection

Kindly please check more items and datasheet from below links:
Product link:  http://www.kingtronics.com/pdf/2-Surge-Arresters.pdf