Electronic power supplies are essential components in a wide range of electronic devices, from smartphones to industrial equipment. In India, electronic power supplies must comply with the Bureau of Indian Standards (BIS) certification to ensure their safety, reliability, and effectiveness. In this blog post, we will discuss the design requirements for electronic power supplies to get BIS certification and how circuit designers can meet these requirements.
In This Article
Input Voltage Range
The input voltage range is the range of voltages that the power supply can accept. For AC input, the range is 90V to 264V, which covers the standard voltage range in India. For DC input, the range is 80V to 370V, which allows for a wide range of DC input sources.
Output Voltage and Current
The output voltage and current are the main parameters of the power supply. The voltage must be between 5V to 60V DC, and the current must be between 100mA to 20A, which covers a wide range of applications from low-power devices like smartphones to high-power devices like industrial equipment.
Efficiency
The efficiency of a power supply is the ratio of output power to input power. The higher the efficiency, the less power is wasted as heat, and the more efficient the power supply is. The BIS certification requires a minimum efficiency of 70% for low-power devices and 80% for high-power devices.
Protection Circuits
The power supply must have several protection circuits to ensure the safety and reliability of the device. The overvoltage protection circuit protects against output voltage exceeding the rated voltage by more than 5%, while the overcurrent protection circuit protects against output current exceeding the rated current by more than 10%. The short-circuit protection circuit protects against short-circuit conditions, and the thermal protection circuit protects against overtemperature conditions.
EMI/EMC Compliance
The power supply must comply with EMI/EMC (electromagnetic interference/electromagnetic compatibility) standards to ensure that it does not interfere with other electronic devices or receive interference from them. The radiated emission standard specifies that the power supply must have a radiated emission level of less than 30dBμV/m at 10 meters, while the conducted emission standard specifies that it must have a conducted emission level of less than 50dBμV for AC input and less than 70dBμV for DC input. The power supply must also be immune to ESD up to 4kV.
Isolation
The isolation between the input and output circuits is crucial for the safety of the power supply. The BIS certification requires an isolation voltage of at least 3kV AC or 4.2kV DC to ensure that the user is protected from any electric shock hazards.
Safety Compliance
The power supply must comply with safety standards such as IEC 60950-1 for safety of information technology equipment and IEC 60065 for safety of audio, video, and similar electronic apparatus. These standards ensure that the power supply is designed and manufactured to prevent any potential hazards to the user.
Bureau of Indian Standards (BIS) has specific requirements for the clearance and creepage distances for power supplies to ensure safety. These values depend on the working voltage of the equipment and are specified in the relevant Indian Standard.
As per the Indian Standard IS 13252(Part 1):2010, the clearance and creepage distances for power supplies are as follows:
- Clearance distance: The minimum distance through air between two conductive parts or between a conductive part and the nearest conductive surface that is required to ensure electrical safety.
The clearance distance requirements for power supplies are:
- Up to 250V: 3 mm
- 251V to 500V: 6 mm
- Above 500V: 10 mm
- Creepage distance: The shortest distance over the surface of an insulating material between two conductive parts or between a conductive part and the nearest conductive surface that is required to ensure electrical safety.
The creepage distance requirements for power supplies are:
- Up to 250V: 3 mm
- 251V to 500V: 6 mm
- Above 500V: 10 mm
It is important to note that these values are subject to change and the latest Indian Standard should always be referred to for specific requirements.
Marking and Labeling
The power supply must be properly marked and labeled with information such as the manufacturer’s name and address, product model number, input and output voltage and current ratings, and safety certifications. This information helps the user to identify and select the right power supply for their needs and ensures that the power supply is compliant with BIS standards.
Conclusion
In conclusion, the BIS certification requires electronic power supplies to meet several design requirements, including input voltage range, output voltage and current, efficiency, protection circuits, EMI/EMC compliance, isolation, safety compliance, and marking and labeling. Circuit designers must carefully select components and design circuits that meet these requirements to ensure that the power supply is safe, reliable, and effective. By following these guidelines, circuit designers can design electronic power supplies that comply with BIS standards and meet the needs of customers in India.
For more information you can visit on official website of BIS.
