Introduction to UL2738 Testing Standards for Wireless Charging

As an emerging high-tech charging method, wireless charging has attracted a lot of attention in recent years. Its excellent user experience and the convenience of being free from cables have made it increasingly popular among consumers. The quality and safety of wireless charging products are issues that both consumers and manufacturers must pay attention to. UL2738 is the testing standard for wireless charging products, and this article will elaborate on it from three aspects: component analysis, testing items, and standard requirements.

I. Product Component Analysis

Wireless charging products mainly consist of two parts: the wireless charger and the charging device. The wireless charger can be simply divided into the transmitter power supply and the transmitter array, while the charging device can be divided into the receiver array and the receiver power supply.

The transmitter power supply in a wireless charger is mainly a regulated power supply, used to provide a stable voltage to the transmitter array to prevent voltage fluctuations from affecting the wireless charging effect. The transmitter array is an array composed of multiple coils, used to generate a magnetic field and transfer energy through the principle of electromagnetic induction. Similarly, the receiver array is also an array composed of multiple coils, whose main function is to receive the electromagnetic field emitted by the transmitter and convert it into electrical energy, while the receiver power supply is a DC power supply used to provide current to the receiver array.

II. Testing Items

The UL2738 testing standard is very comprehensive for wireless charging products, mainly including the following aspects:

1. Product appearance and safety level testing: Includes testing the product's appearance as well as safety testing for aspects such as waterproofing, fire resistance, and shock resistance.

2. Charging rate test: Tests whether the charging speed of the wireless charger meets industry standards.

3. Interference analysis test: Tests whether the electromagnetic interference generated by the wireless charging device meets national standards, ensuring that the use of the wireless charging device does not interfere with surrounding electronic devices.

4. Energy efficiency verification test: Tests whether the energy efficiency of the wireless charging device meets industry standards, ensuring that the product's energy efficiency performance is not lower than the standard requirements.

5. Telemetry data test: Tests data such as temperature and voltage while the wireless charging device is operating to ensure that the wireless charging device meets requirements during operation.

III. Standard Requirements

UL2738 is a mandatory testing standard for wireless charging products. It requires that during the testing process, the stability, service life, electrical safety, electromagnetic compatibility, complications, durability, and appearance of wireless charging products should all meet the required standards.

Among them, electrical safety is one of the important requirements for wireless charging products. The UL2738 standard stipulates that wireless chargers and charging devices should adopt measures such as fire protection, waterproofing, shock resistance, and leakage prevention, and the electrical safety level should comply with the standard requirements.

At the same time, the electromagnetic compatibility of wireless charging products is also a key issue to consider. The UL2738 standard specifies that wireless chargers and charging devices should meet requirements in various tests, including radio frequency emission tests, IEC testing, CDN testing, ESD testing, and electrostatic discharge tests.