Output Power (W)
E
ffi
ci
e
n
c
y
0
2
4
6
8
10
12
14
16
0
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
D002
15-W RX 8 V
15-W RX 10 V
15-W RX 12 V
Test Setup
17
SLVUAO6 – June 2016
Copyright © 2016, Texas Instruments Incorporated
bq501210 bqTESLA™ Wireless Power TX EVM
6.2.2.2
Apply Receivers
Place the15-W RX on the top of the transmitting coil. Align the centers of the RX and TX coils. In the next
few seconds, observe that there is a "beep" from the TX and the status LED D6 flashes. Depending on the
15-W RX chosen, there may be LED indicators. These are an indication that communication between the
transmitter and the receiver is established and that power transfer has begun.
•
The TX status LED, D6, flashes green during power transfer.
•
Typical RX output voltage is 10 V, and the output current range is 0 mA to 1.5 A.
•
Observe a continuous sine-wave on the TX test point TP15 when power transfer is active; the
frequency is 130 kHz.
•
Make tests and measurements applicable to a normal 10-V power supply.
6.2.2.3
Efficiency
Measure the system efficiency by measuring the output voltage, output current, input voltage, and input
current and calculate efficiency as the ratio of the output power to the input power. Connect voltage
meters at the input and output of TX and RX (see
). Average the input current (the communication
pulses modulate the input current, distorting the reading).
shows efficiency.
Figure 10. Efficiency vs Power, bq501210EVM-756 Transmitter and a 15-W Receiver
6.2.2.4
TX LED Behavior
The LED behavior of D6, D7 and D8 is set by the resistance from the LED_MODE pin to ground. The
default for the bq501210EVM-756 is 42.2 k
Ω
, making this LED CONTROL OPTION 1 (as seen in the
bq501210 data sheet, Table 3, LED Modes.
D2 – Green LED indicator of 3.3-V DC-to-DC converter. During STANDBY (no RX), D2 flashes at about a
one-half second rate. D2 is ON during power transfer and during fault conditions.
D6 – Green status LED driven by bq501210 (LED-A). Blinks during power transfer, D6 blinks about once
per second for 5 W or 15 W and about twice per second for the proprietary 10 W solution with the
bq51025 RX.
D7 – Red status LED driven by bq501210 (LED-B). On during fault condition (for example: FOD failure
and Temperature Fault) and blinks during FOD warning.
D8 – Yellow status LED driven by bq501210 (LED-C). D8 is unused for LED Option 1.
D9 – Green LED controlled by TX input voltage. Only on when the input voltage is between 8 V and 12 V.
D12 – Green LED controlled by TX input voltage. On when the input voltage is above 12 V. See
for more information on D9 and D12.