APPLICATION
>>Application background:
1.RS485/232 take a long line, vulnerable to over voltage
2.RS485/232 line in the outdoor, vulnerable to lightning
3.RS485/232 is easy to be disturbed by other signals
>>Program description and notes:
1 Front end uses a large flow of GDT, leakage current.
2 Back end using fast response time of TVS to clamp the voltage to low level, effectively protect the RS485/232 controller.
3 In the middle part of circuit to use PTC for decoupling, let the front end GDT action easily for discharge current.
4 This scheme meets the standards of IEC61000-4-2, GBT17626.2 and other static standards, such as IEC61000-4-5, GBT17626.5 and so on.
5 The same TVS and GDT are used in both modes of the differential and common in this program, and no protection dead angle
1 Surveillance / Security system
2 Entrance guard system
3 Railway signal control lamp
4 Intelligent Transportation Systems
5 Meter / meter instrument
1.RS485/232 take a long line, vulnerable to over voltage
2.RS485/232 line in the outdoor, vulnerable to lightning
3.RS485/232 is easy to be disturbed by other signals
>>Program description and notes:
1 Front end uses a large flow of GDT, leakage current.
2 Back end using fast response time of TVS to clamp the voltage to low level, effectively protect the RS485/232 controller.
3 In the middle part of circuit to use PTC for decoupling, let the front end GDT action easily for discharge current.
4 This scheme meets the standards of IEC61000-4-2, GBT17626.2 and other static standards, such as IEC61000-4-5, GBT17626.5 and so on.
5 The same TVS and GDT are used in both modes of the differential and common in this program, and no protection dead angle
6 Meet 10/700uS (40ohm equivalent resistance) 1.2/50uS and 8/20 standards.
>>Program application:
1 Surveillance / Security system
2 Entrance guard system
3 Railway signal control lamp
4 Intelligent Transportation Systems
5 Meter / meter instrument
6 Optical switch/converter/tranceiver
>>Protection circuit diagram and product appearance:
>>PulseTake Protection Device
1 TVS1/TVS2/TVS3：SMBJ15CA
2 GDT: PTC471N (Mid-level lightning protection) PWF471N（High-level lightning protetction）
3 PTC1/PTC2： P250-120