Delphi Hands Free (Car)

Model Number

DH-500

Hands-Free
Cell Phone Speaker/Microphone

Quick & Easy to install ! Patented technology eliminates feedback and echo for comfortable hands-free communication with cellphone. For All Cell Phones Using a StandardRound-Pin 2.5mm Jack. Adapters needed for some phone models. Compatible with CDMA, TDMA and GSM Phones.

Features

• Allows parties on both sides of the conversation to talk and listen at once.
  
• Battery-powered. The only cable needed is the one from your mobile phone to the hands-free unit(included)
  
• Uses a special noise suppression circuit so that surrounding noise is nearly eliminated, even at highway speeds.
  
• Uses an energy-saving circuit to turn itself on and off automatically. Average battery life with normal use is about 6 months
• Energy-saving circuit turns off the unit after 2 minutes of silence from other party.

DH-500 Tips for Installation

Patent in DH-500

The patent relates to an electronic circuit that realizes the following function:

The circuit is connected to the output of a microphone and amplifies human voices selectively. The circuit recognizes human voices from signals falling within a certain range of frequencies. The output of the selecting circuit controls the degree of amplification of the microphone output

This circuit has been burnt into a silicon in the form of an analogue chip. The design belongs to Pan Communications, Inc., while the chip was completed by Hitachi engineers. The chip is currently supplied by Renesas, a joint venture between Hitachi and Mitsubishi Electric.