On October 24, 2023, the US FCC released KDB 680106 D01 for Wireless Power Transfer. The FCC has integrated the guidance requirements proposed by the TCB workshop in the past two years, as detailed below.
The main updates for wireless charging KDB 680106 D01 are as follows:
1.The FCC certification regulations for wireless charging are FCC Part 15C § 15.209, and the frequency of use of the product must comply with the range of Part 15C § 15.205 (a), that is, devices authorized by Part 15 must not operate in the 90-110 kHz frequency band. In addition to meeting regulatory requirements, the product also needs to comply with the conditions of KDB680106.
2.According to the new version of KDB (KDB680106 D01 Wireless Power Transfer v04) for wireless charging devices announced on October 24, 2023, if the following conditions are not met, ECR needs to be run! The applicant submits consultation to the FCC official in accordance with KDB guidelines to obtain FCC authorization, which is the pre test laboratory inquiry.
But the product can be exempted when it meets all the following conditions:
(1) Power transmission frequency below 1 MHz;
(2) The output power of each transmitting element (such as coil) is less than or equal to 15W;
(3) Provide the maximum allowable load for testing the physical contact between the periphery and the transmitter (i.e. direct contact between the surface of the transmitter and peripheral equipment casing is required);
(4) Only § 2.1091- Mobile exposure conditions apply (i.e. this regulation does not include § 2.1093- Portable exposure conditions);
(5) The RF exposure test results must comply with the restrictions;
(6) A device with more than one charging structure, for example: a device may use three coils with a power of 5W or one coil with a power of 15W. In this case, both states need to be tested, and the test results must meet condition (5).
If one of the above does not meet the requirements, ECR must be performed. In other words, if the wireless charger is a portable device, ECR must be performed and the following information must be provided:
-Working frequency of WPT
-Power of each coil in WPT
-Mobile or portable device demonstration operation scenarios, including RF exposure compliance information
-Maximum distance from WPT transmitter
3. The wireless charging device WPT has defined device requirements for transmission distances ≤ 1m and>1m.
A. If the WPT transmission distance is ≤ 1m and meets the KDB requirements, there is no need to submit KDB consultation.
B. If the WPT transmission distance is ≤ 1m and does not meet this KDB requirement, KDB consultation needs to be submitted to FCC for authorization approval.
C. If the WPT transmission distance is greater than 1m, KDB consultation needs to be submitted to FCC for authorization approval.
4. When wireless charging equipment WPT is authorized in accordance with FCC Part 18 or Part 15C regulations, whether it is through FCC SDoC or FCC ID Certification procedures, KDB consultation must be submitted to FCC for approval before it can be considered a valid authorization.
5. For the test of RF exposure, the field strength probe is not small enough (the center of the probe sensing element is more than 5 mm from the outer surface of the probe). It is necessary to calculate the results at 0mm according to the requirements of section 3.3, and for the 2cm and 4cm parts, calculate whether the test results are within a 30% deviation. Provide formula calculation methods and model evaluation methods for field strength probes that do not meet the testing distance requirements. And this result needs to go through PAG during the TCB certification stage.
Figure 1: Example of probe (yellow) measurement near WPT equipment (red/brown) point
The probe radius is 4 millimeters, so the closest point to the device that can measure the field is 4 millimeters away from the meter (this example assumes that probe calibration refers to the center of the sensing element structure, in this case it is a sphere). The radius is 4 millimeters.
The data at 0 mm and 2 mm must be estimated through the model, and then the same model must be validated by comparing it with actual measurements at 4 mm and 6 mm, in order to locate the probe and collect valid data.
6.For WPT transmitters powered by loads with a distance not exceeding ⼀⽶, when designing WPT with multiple radiation structures, the distance of the load should be considered as shown in Figure 3, and measurements should be taken between the receiver and the nearest transmission structure.
Figure 2
a) For a multi receiver system (where there are two receivers, as shown in the RX1 and RX2 tables), the distance limit must apply to all receivers involved in the charging process.
b) The wireless charging device WPT system is considered a "long-distance" system because it can function when the RX2 is more than two meters away from the transmitter.
Figure 3
For multi coil transmitter systems, the maximum distance limit is measured from the nearest edge of the coil. The load configuration for WPT operation within a certain range is marked in green font. If the load can supply power for more than one meter (red), it should be considered as "long-distance".
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Post time: Jan-09-2024
