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Projects

• Li-Ion Stationary Batteries
• Li-Ion HEV Bus Batteries
• Redundant Satellite Link System
• Precise Time-Frequency Standard

• Li-Ion Stationary
  Batteries

  Challenge:
  For many years, lead-acid batteries have been the workhorses for stationary battery requirements. Relative to lead-acid batteries, modern Li-ion batteries offer many distinct advantages, including safety, higher energy density, longer life and lower maintenance costs. But Li-ion batteries have different voltages and active management requirements. The challenge given to the ZXTECH principals was, “how can you replace lead-acid batteries with Li-ion batteries to realize these benefits?”

  Solution:
  ZXTECH has developed proprietary technologies for designing Li-ion batteries that can emulate lead-acid batteries in these applications, allowing transparent drop-in replacement in products designed for lead-acid batteries.

• Li-Ion HEV Bus
  Batteries

  Challenge:
  Electric and hybrid electric vehicles are the key for a more energy efficient future. Due to energy density and product life considerations, Li-ion batteries are the technology of choice for future electric vehicles. But to provide these benefits, Li-ion batteries require sophisticated monitoring and control systems. Further, high capacity battery systems, such as those required for buses and trucks, need modular battery systems, which present additional unique design challenges. The challenge given to the ZXTECH principals was, “how do you design modular high capacity Li-ion battery systems for large electric vehicles?”

  Solution:
  ZXTECH has developed proprietary technologies for modular high capacity Li-ion battery systems, such as the HEV bus battery shown here. This system supports up to eight battery modules and includes failsoft features for uninterrupted vehicle operation.

• Redundant Satellite
  Link System

  Challenge:
  Satellites provide the most cost-effective communication links for many applications. Until May 19, 1998, when the primary and backup control systems for Galaxy IV failed almost all network operators had made little or no provisions for failure of their satellite links. After all, why should they? No satellite had ever failed before. Nonetheless, on that day, more than a dozen nationwide network operators experienced total outage that affected more than 10 million customers and the outage lasted for up to two weeks. The challenge given to the ZXTECH principals by the world’s largest wireless network operator was, “how do we ensure that nothing like this ever happens to our customers again?”

  Solution:
  In less than nine months, the ZXTECH principals designed, started manufacturing and began nationwide field deployment of a redundant satellite network that included custom satellite downlink receivers, steerable satellite antennas, network bridge-routers and precision transmission frequency standards. Connecting more than 10,000 pieces of equipment to a unified network, the system was capable of automatically and autonomously linking to any satellite in geostationary orbit over the equator that was carrying the network operator’s signal. As it turned out, this didn’t happen any too soon. Nearly one year later to the day, the replacement satellite experienced a loss of control. As designed, the system automatically switched to the backup satellite. Fortunately, within 6 hours, they were able to regain control of the primary satellite and the system, as expected, automatically reverted back to primary satellite.

• Precise
  Time-Frequency
  Standard

  Challenge:
  For a variety of purposes, communication networks require very stable precise time and frequency standards (parts in 10-10 or better). To accomplish this, precise reference signals are distributed across vast networks over bandwidth-limited transmission networks. Due to the transmission networks, the incoming reference signals have very good long term accuracy, but very poor short term stability. To overcome this and to provide for system reliability, local sites are equipped with 10MHZ time-frequency standards, which are locked to one or more incoming reference signals. However, given the level of precision (10-10), it can take a very long time to lock the local standard to an incoming reference signal. (For example, it would take a frequency counter 1,000 seconds to make a single measurement of 10MHz oscillator with a level of precision to 10-10 and, over a noisy transmission network, it would require many such measurements.) At the time, typical state-of-art equipment required approximately 4-5 hours to lock to an incoming reference signal. This severely limited the performance of the networks and imposed expensive operating requirements on the interconnecting transmission networks. The challenge given to the ZXTECH principals was, “how can you speed up the reference-standard lock time without further increasing the interconnecting transmission network cost?

  Solution:
  The ZXTECH principals developed a new patented technology based on the use of predictors that brought typical reference-standard lock times down to approximately 1,000 seconds… essentially the same time that was required to make a single frequency counter measurement! Further, the process was adaptive within wide operating ranges, enabling use over interconnecting transmission networks with profoundly lower quality and cost! This dramatically increased the client company’s sales and opened vast new markets to them.