Файл: wirelesspowerspecificationpart1.pdf

Figure 3-13: Primary Coil of Power Transmitter design A4

Table 3-9: Primary Coil parameters of Power Transmitter design A4

Power Transmitter design A4 contains two Primary Coils, which are mounted in a Shielding block (see Section 3.2.4.1.2) with their long axes coincident, and a displacement of mm between their centers. See Figure 3-14.

Figure 3-14: Dual Primary Coils (top view)

3.2.4.1.2Shielding

As shown in Figure 3-15, soft-magnetic material protects the Base Station from the magnetic field that is generated in the Primary Coils. The top face of the Shielding block is aligned with the top face of the Primary Coils, such that the Shielding surrounds the Primary Coils on all sides except for the top face. In addition, the Shielding extends to at least 2.5 mm beyond the outer edge of the Primary Coils, and has a thickness of at least 5 mm. This version 1.1.1 of the System Description Wireless Power Transfer, Volume I, Part 1, limits the composition of the Shielding to a choice from the following list of materials:

Mn-Zn-Ferrite Dust Core — any supplier

Interface

Surface

5 mm min.

dz

Figure 3-15: Primary Coil assembly of Power Transmitter design A4

3.2.4.1.3Interface Surface

As shown in Figure 3-15, the distance from the Primary Coil to the Interface Surface of the Base Station is mm, across the top face of the Primary Coil. In addition, the Interface Surface of the Base

Station extends at least 5 mm beyond the outer diameter of the Primary Coil.

3.2.4.1.4Separation between multiple Power transmitters

In a Base Station that contains multiple type A4 Power Transmitters, the Primary Coil assemblies of any pair of Power Transmitter shall not overlap—(informative) Note that the two Primary Coils within an assembly do overlap as defined in Section 3.2.4.1.1.

3.2.4.2Electrical details

As shown in Figure 3-16, Power Transmitter design A4 uses a full-bridge inverter to drive the Primary Coils and a series capacitance. In addition, Power Transmitter design A4 shall operate coil selection switches SWu and SWl such that only a single Primary Coil is connected to the inverter.

Within the Operating Frequency range of 110…180 kHz, each Primary Coil in the assembly of Primary Coils and Shielding has a self inductance μH. The value of the series capacitance is nF. The input voltage to the full-bridge inverter is 5…11 V. (Informative) Near resonance,

the voltage developed across the series capacitance can reach levels up to 40 V pk-pk.

Power Transmitter design A4 uses the Operating Frequency and the input voltage to the full-bridge inverter to control the amount of power that is transferred. In order to achieve a sufficiently accurate adjustment of the power that is transferred, a type A4 Power Transmitter shall be able to control the frequency with a resolution of 0.5 kHz, and the input voltage with a resolution of 50 mV or better.

When a type A4 Power Transmitter first applies a Power Signal (Digital Ping; see Section 5.2.1), the Power Transmitter shall use an Operating Frequency of 130 kHz, and an input voltage of 8 V. If the Power Transmitter does not to receive a Signal Strength Packet from the Power Receiver, the Power Transmitter shall remove the Power Signal as defined in Section 5.2.1. The Power Transmitter may reapply the Power Signal multiple times at an Operating Frequency of 130 kHz using consecutively higher input voltages

3.2.5Power Transmitter design A5

Power Transmitter design A5 enables Guided Positioning, and has a design similar to Power Transmitter design A1. See Section 3.2.1 for an overview.

3.2.5.1Mechanical details

Power Transmitter design A5 includes a single Primary Coil as defined in Section 3.2.5.1.1, Shielding as defined in Section 3.2.5.1.2, an Interface Surface as defined in Section 3.2.5.1.3, and an alignment aid as defined in Section 3.2.5.1.4.

3.2.5.1.1Primary Coil

As shown in Figure 3-17, the Primary Coil has a circular shape and consists of one or two layers of type 1 or type 2 litz wire, having in total 105 strands of no. 40 AWG (0.08 mm diameter), or equivalent. Table 3- 12 lists the dimensions of the Primary Coil.

do

di

dc

Figure 3-17: Primary Coil of Power Transmitter design A5

Table 3-12: Primary Coil parameters of Power Transmitter design A5

3.2.5.1.2Shielding

As shown in Figure 3-18, soft-magnetic material protects the Base Station from the magnetic field that is generated in the Primary Coil. The Shielding extends to at least 2 mm beyond the outer diameter of the Primary Coil, has a thickness of at least 0.5 mm, and is placed below the Primary Coil at a distance of at most mm. This version 1.1.1 of the System Description Wireless Power Transfer, Volume I, Part 1, limits the composition of the Shielding to a choice from the following list of materials:

Material 44 — Fair Rite Corporation.

Material 28 — Steward, Inc.

CMG22G — Ceramic Magnetics, Inc.

Kolektor 22G — Kolektor.

LeaderTech SB28B2100-1 — LeaderTech Inc.

TopFlux “A“— TopFlux.