neilmcc
Joined: 15 Dec 2006
Posts: 1
|
 15 Dec 2006 10:22 Switching circuit |
|
|
|
I am trying to install a Parrot Bluetooth in car mobile phone set up and this has a mute the radio facility when a call comes in. The factory wiring in the car radio has a mute input. When I connect the Parrot phone mute wire to the mute input on the car radio, the radio mutes immediately and stays that way whether a call comes in or not.
I have 0V coming out of the phone kit mute wire when no call in progress and this goes to 1.75V when a call comes in. There is 4.5V coming out of the radio mute connection. If I touch the 4.5V radio mute wire to earth it will mute the radio.
I want some sort of circuit that switches the 4.5V radio output to earth when the phone mute wire goes to 1.75V. I think a relay switch would do it, with the 1.75V phone line driving the coil and switching the 4.5V radio circuit to earth when closed. The problem is I cannot find a relay switch that can be driven by only 1.75V.
Any ideas?
|
|
