Speaker Driver {Special Companies}

HiVi is a leading manufacturer of stereophile quality audio systems. Employing some of the worlds’ finest electro-acoustical technicians and craftsmen, the company established state-of-the art R+D facilities in Toronto, Canada in 1994 and was fueled by early successes with innovative driver designs. In 1997, HiVi merged with highly-regarded speaker manufacturer Swans Speaker Systems and opened corporate offices in Monterey Park, California. Respected audio designer Frank Hale, former president of Swans, continues to serve today as Chief Designer for HiVi Speaker Systems.

HiVi’s proprietary driver technologies including Planar Ribbon Tweeters are employed by many of the audio industry’s top brands. With focused re-investment in research and development, HiVi continues to advance the art and science of electro-acoustical engineering. The merger with Swans provided the opportunity for complete system research and design.

HiVi’s range of drivers and complete speaker systems have been established in niche European, Asian and North American markets for more than a decade. HiVi wholly owns 300 retail stores across Asia, with direct retail presence in an additional 700 locations. With critical success has come substantial growth, and HiVi’s markets continue to expand globally. The HiVi product range has also grown to serve these markets to include high-quality car audio systems, custom home installation speakers and multi-media systems along with home theater systems and drivers.

HiVi founder and president Hong Bo Yao continues to drive the company to new heights. Ongoing research and development programs continue to produce innovative products and technologies - raising the bar on what is possible in high-quality audio reproduction. HiVi is capitalizing on these technologies and extending product offerings successfully into new markets and new categories - converting listeners to audiophiles with uncompromised excellence.

PHASE SEQUENCE DETECTOR {CIRCUIT LOGIC}

In a three-phase system, three circuit conductors carry three alternating currents (of the same frequency) which reach their instantaneous peak values at different times. Taking one conductor as the reference, the other two currents are delayed in time by one-third and two-thirds of one cycle of the electrical current.

The circuit logic is based on this phase difference. The first supply line, line L1, is taken as reference and is called R phase. Now the microprocessor checks which line reaches its peak value next, L2 or L3. If it’s L2 second line is called Y phase and the sequence is RYB. If it’s L3 then third line is Y phase and the phase sequence is RBY. 

PHASE SEQUENCE DETECTOR {Abstract}

The instrument presented here, the PHASE SEQUENCE DETECTOR WITH MOTOR ROTATION SELECTOR permits the electrical contractor or industrial maintenance electrician to permanently connect and tape the terminals of the motor being installed, without having to first energize the motor by a temporary hookup from a power source, if available, to determine motor rotation.

 Therefore, this relay instrument eliminates the need for temporary connections that can be time consuming, costly and quite hazardous, particularly where many large, high-voltage motors are involved. Also, certain types of drives should never be rotated in the wrong direction. In such cases, the temporary hookup or trial method, having a fifty-fifty chance of being wrong, can do serious harm.