| Customer Spotlight|
Innovation in Wireless Power Design
Facing a complex multiple discipline engineering problem, Splashpower Ltd. (Cambridge, UK) turned to the Synopsys’ Saber multi-domain system simulator to analyze and optimize their system design. Bill Campbell, Splashpower’s CEO, explains how Saber enabled the design team to realize a truly innovative product idea.
Portable gadgets free people from their offices and homes. But while they have fundamentally changed the way that people work and use their leisure time, they still depend on the use of a power cord for re-charging. Splashpower is bringing technology to change that: its products enable wireless recharging by completely removing the need for wires.
Splashpower’s universal wireless power solution comprises two parts: the charging pad and a SplashModule, either as an add-on receiver or integrated within each portable device. The product benefits are significant. Bill Campbell explains: “Consumers no longer need a different charger for each device. They can simultaneously charge several devices by simply placing the devices on a pad and allowing the system to re-charge the devices. The re-charging process becomes easy and natural. People can leave home or work with their gadgets fully charged.”
Widespread adoption of the technology in places such as hotels and airports will enable travelers to charge up on the move without having to bring their chargers from home. For wireless device manufacturers, there is another cost benefit: wireless re-charging removes the need to produce and ship external wall chargers.
Figure 1: Wireless Re-charging with Splashpower’s Technology
Inductive Power Transfer Challenges
Inductive coupling is well-established as a means of power transfer. Electric toothbrushes, electric vehicles and smart cards commonly use electromagnetic induction to transfer power from a source to the product. However, the technology had never been applied to multiple devices or for devices positioned at any orientation (e.g. wherever the consumer wants to place his or her product).
One of the main technical difficulties encountered with the design of wireless charging technology is achieving high efficiency. The design team must select the right circuit topology for the application and optimize the system by balancing the electronic and magnetic effects.
In developing the electromagnetic induction technology, the Splashpower engineering team had to address a number of difficulties not encountered by traditional applications of the technology. For example, the system had to deliver power to multiple devices, even though devices tend to have different power requirements,
Another engineering challenge was ensuring that the solution provided universal charging support. The SplashModule can be adjusted for different portable devices with different charging requirements. Changing device charging requirements must be accomplished without compromising the charging efficiency.
To complicate matters, the engineering team was tasked with producing a pad that was scalable in size, could be used standalone or integrated into furniture, automobiles, and so on.and at a price point that was acceptable to the consumer market. Finally, the technology had to meet worldwide regulations of electromagnetic products used by consumers.
Splashpower solved these problems by developing new technology that led to a number of patent applications. Engineers at Splashpower are using the Saber simulator solution to enable these technologies to become commercial products.
Solving Complex Problems with Saber
Splashpower engineers chose the Saber simulator solution because it could easily model and simulate the complex electromagnetic environment of their advanced wireless power transmission system.
Within the Saber environment, the Splashpower team can simulate the entire charging system, including the charger electronics, the magnetic link, and the module electronics. Bill Campbell explains the significance of the Saber environment: “To develop this technology the design team needed to understand how the different blocks interact together. There has been no previous work done in this field that we could reference, so the traditional design approach of partitioning the system and using standalone tools was just not possible. Therefore we needed an environment that could model the whole system and consider multiple design disciplines simultaneously.”
The capability of Saber to simulate different domains (magnetic, digital, analogue, thermal) with varying levels of detail allowed Splashpower to address the block and system interaction problems well before the physical hardware prototype was constructed. These problems extend beyond the system integration challenges to include second order effects when combining complex sub-systems. These issues cannot be observed at the top level of the system and therefore require a multi-domain simulator.
As a result of using Saber, the development team detected electronic and magnetic problems much earlier in the design cycle before the physical circuit was completed. This saved significant time and cost compared to the traditional approach of physical hardware prototype design and debugging.
Saber also helped the engineering team to develop the product-specific charging modules. Because it provides a model of the complete system including reconfiguring the charging module with different components, the team could test the system under different conditions using a wide range of positions between the charger and the module. With this success, Saber will be used as a virtual prototyping environment to help Splashpower’s application engineers adapt the charging module for different customers.
Without a multi-domain simulation solution, the Splashpower team would have had to use physical prototypes alone to prove their system. Saber allowed the team to investigate alternative solutions both quickly and accurately. Campbell describes the key benefit: “Saber saved us significant time on the project schedule which would otherwise have been spent coming to grips with physical hardware prototypes. Saber also gives us accurate analysis of the complex electro-magnetic coupling in our power conversion and transmission system – something that would have been very difficult and enormously costly to achieve with a hardware prototype.”
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