2027-35-B vs 2095-160-BLF
| Part Number |
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| Category | Gas Discharge Tube Arresters (GDT) | Gas Discharge Tube Arresters (GDT) |
| Manufacturer | Bourns Inc. | Bourns Inc. |
| Description | GDT 350V 15% 10KA THROUGH HOLE | GDT 1600V 20% 5KA THROUGH HOLE |
| Package | Axial Cylinder | Axial Cylinder |
| Series | 2027 | 2095 |
| Mounting Type | Through Hole | Through Hole |
| Package / Case | Axial Cylinder | Axial Cylinder |
| Tolerance | ±15% | ±20% |
| Number of Poles | 2 | 2 |
| Voltage - DC Spark Over (Nom) | 350V | 1600V |
| Impulse Discharge Current (8/20µs) | 10000A (10kA) | 5000A (5kA) |
| Fail Short | No | No |
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1. What is a gas discharge tube arrester?
A gas discharge tube arrester is a device that uses the principle of gas discharge to achieve overvoltage protection. It is mainly composed of a ceramic sealed discharge tube, which contains two or more metal electrodes with gaps and is filled with inert gas such as argon or neon. When the external voltage exceeds the breakdown voltage of the discharge tube, the gas in the tube is ionized under the action of the electric field to form a conductive channel, which quickly discharges the large current and high voltage generated by the lightning strike, thereby protecting the subsequent circuit from damage. Once the overvoltage disappears, the discharge tube will return to a high-resistance insulation state, waiting for the next impact.
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2. What is a GDT gas discharge tube?
A GDT gas discharge tube (Gas Discharge Tube) is a device used to protect electronic equipment from transient voltage damage. It is mainly composed of one or more discharge gaps, sealed in a ceramic cavity or glass tube filled with inert gas. Under normal working conditions, the GDT maintains a high resistance state; when the voltage exceeds its breakdown voltage, the gas in the gas discharge tube is ionized to form a conductive path, which introduces the surge current into the ground, thereby protecting the equipment. Once the overvoltage disappears, the GDT returns to a high impedance state and waits for the next shock.
Working Principle
The working principle of GDT is based on the gas discharge phenomenon. Under normal operating voltage, the inert gas inside the GDT remains non-conductive and the device is in a high impedance state. When the voltage reaches or exceeds its breakdown voltage, the gas ionizes to form a plasma path, causing the GDT to present a low impedance state, directing the surge current into the ground, thereby protecting the device. After the overvoltage disappears, the GDT returns to a high impedance state. -
3. How does GDT work?
The working principle of GDT (gas discharge tube) is mainly based on its electrical characteristics, which are determined by the type of gas, pressure and electrode distance. The GDT is filled with inert gas (such as neon or argon) and maintains a certain pressure. When the voltage across the GDT rises to a value greater than its discharge voltage, the gas begins to ionize, causing the discharge tube to conduct, changing from a high impedance state to a low impedance state, thereby rapidly reducing the voltage across the two ends.
The working process of GDT can be divided into the following stages:
Insulation state: When there is no surge, GDT is in an open circuit state, which is equivalent to a high-impedance insulator with a very large resistance (usually greater than 1000 megohms), almost no leakage current or very small leakage current.
Discharge state: When the voltage across the GDT rises to a value greater than its discharge voltage, the gas begins to ionize and the discharge tube is turned on. At this time, the GDT changes from a high-impedance state to a low-impedance state, causing the voltage across its two ends to drop rapidly, usually by tens of volts.
Follow-current effect: Due to the follow-current characteristics of the gas discharge tube, even if the surge voltage disappears, as long as a certain voltage (usually above 15V) is maintained at both ends, the GDT will remain in the on state and continue to conduct electricity.
The application scenarios of GDT mainly include lightning surge protection, which is suitable for lightning protection of AC and DC power supplies and signal circuits. It can quickly turn on when a surge arrives, limit the voltage peak, and protect the connected electronic equipment from damage. -
4. What are the advantages and disadvantages of GDT?
Advantages: before breakdown, it is equivalent to an open circuit, with high resistance and low leakage current; after breakdown, it can pass a large current with low voltage drop; the pulse flow rate is large, and the commonly used specifications are 2KA, 10KA, 20KA, etc., and the highest can reach more than 100KA; the junction capacitance is low, and most of them are less than 2pF.
Disadvantages: The response speed is slow, generally 0.2~0.3 microseconds, and the fastest is about 0.1 microseconds; the breakdown voltage consistency is poor, the dispersion is large, generally ±20%; the breakdown voltage has only a few specific values.
