How about the prospect of wireless charging in smart wearable
2021-06-12
Wireless charging and wearable devices complement each other
The basic principle of wireless charging is to transmit electric energy through electromagnetic induction. Specifically, alternating current is applied to the transmitting coil inside the charging base to generate a magnetic field, which causes the receiving coil in the nearby mobile device to generate an induced voltage. Charge the battery of the device. Compared with charging via USB or charging head, wireless charging has additional energy conversion loss, so the charging efficiency is lower, and the charging time is longer.
Therefore, there must be a valid reason to use this technology; but in design When it comes to wearable devices, we have very good reasons to include wireless charging. Wearable devices need to be worn on the body for a long time, which determines that it cannot look too conspicuous. It must be small, thin, and not bulky, leaving little space for batteries and related circuits. If it is a relatively simple wearable device such as a fitness tracker, a small battery may be enough to run for a week without charging; however, under the current market trend, wearable devices have more and more functions, which is reflected in smart watches. It is particularly obvious. Many smart watches not only provide fitness tracking functions, but are also equipped with full-color touch screens, making calls, sending messages and other very power-consuming features, even if they use the most efficient lithium ion (Li-Ion) and lithium polymer (Li-Pol) today.
Battery technology can't save their battery life.
From the product evaluation point of view, most smart watches must be charged in less than a day or two, and some may not even last for a day, including the familiar Apple Watch. When there is no solution to the problem of frequent charging, it is necessary to adopt a simpler charging method than plug-in charging, and then it is time for wireless charging to appear. In the wireless charging scenario, to charge the smart watch, you only need to put it on the charging stand, or attach a small circular magnetic connector on the back of the dial like Apple Watch. Due to the small battery capacity of smart watches and other wearable devices, the time required for wireless charging is relatively short. It takes about an hour from zero to full, which is compared with the long wireless charging time of larger mobile devices such as mobile phones. , It is relatively easy to accept. In addition to more convenient charging and acceptable charging time, wireless charging can also allow wearable devices to adopt a completely sealed or waterproof design, which is a very attractive protective feature for electronic devices worn on the body.
In-vehicle application
For electric vehicles, wireless charging is still at an early stage. Most of the on-board wireless charging solutions are still in the trial state, but wireless charging solutions for on-board consoles have emerged. The Freescale WCT-5WTXAUTO wireless charging reference design is one example. . The solution is based on the highly integrated Freescale WCT100xA wireless charging transmitter 5W coil controller topology. It is a Qi standard multi-coil reference design with a transmission efficiency of greater than 65%, and it takes into account the requirements for implementing a wireless charger in a vehicle environment. For unique challenges, such as the problem of input voltage fluctuations, because the voltage provided by a nominal 12VDC car battery under different operating conditions will vary significantly between 6V and 14V.
The basic principle of wireless charging is to transmit electric energy through electromagnetic induction. Specifically, alternating current is applied to the transmitting coil inside the charging base to generate a magnetic field, which causes the receiving coil in the nearby mobile device to generate an induced voltage. Charge the battery of the device. Compared with charging via USB or charging head, wireless charging has additional energy conversion loss, so the charging efficiency is lower, and the charging time is longer.
Therefore, there must be a valid reason to use this technology; but in design When it comes to wearable devices, we have very good reasons to include wireless charging. Wearable devices need to be worn on the body for a long time, which determines that it cannot look too conspicuous. It must be small, thin, and not bulky, leaving little space for batteries and related circuits. If it is a relatively simple wearable device such as a fitness tracker, a small battery may be enough to run for a week without charging; however, under the current market trend, wearable devices have more and more functions, which is reflected in smart watches. It is particularly obvious. Many smart watches not only provide fitness tracking functions, but are also equipped with full-color touch screens, making calls, sending messages and other very power-consuming features, even if they use the most efficient lithium ion (Li-Ion) and lithium polymer (Li-Pol) today.
Battery technology can't save their battery life.
From the product evaluation point of view, most smart watches must be charged in less than a day or two, and some may not even last for a day, including the familiar Apple Watch. When there is no solution to the problem of frequent charging, it is necessary to adopt a simpler charging method than plug-in charging, and then it is time for wireless charging to appear. In the wireless charging scenario, to charge the smart watch, you only need to put it on the charging stand, or attach a small circular magnetic connector on the back of the dial like Apple Watch. Due to the small battery capacity of smart watches and other wearable devices, the time required for wireless charging is relatively short. It takes about an hour from zero to full, which is compared with the long wireless charging time of larger mobile devices such as mobile phones. , It is relatively easy to accept. In addition to more convenient charging and acceptable charging time, wireless charging can also allow wearable devices to adopt a completely sealed or waterproof design, which is a very attractive protective feature for electronic devices worn on the body.
In-vehicle application
For electric vehicles, wireless charging is still at an early stage. Most of the on-board wireless charging solutions are still in the trial state, but wireless charging solutions for on-board consoles have emerged. The Freescale WCT-5WTXAUTO wireless charging reference design is one example. . The solution is based on the highly integrated Freescale WCT100xA wireless charging transmitter 5W coil controller topology. It is a Qi standard multi-coil reference design with a transmission efficiency of greater than 65%, and it takes into account the requirements for implementing a wireless charger in a vehicle environment. For unique challenges, such as the problem of input voltage fluctuations, because the voltage provided by a nominal 12VDC car battery under different operating conditions will vary significantly between 6V and 14V.