What I don't understand is: If the indicator light finds its path to ground
through the opposite side light, that means there is a current flow through
the opposite side light, why doesn't that light come on also? Is it that
the current flow through the lil' indicator light is too little to actually
light the opposite side lamp?
Jim Altman jaltman@altlaw.com non illegitimus carborundum
http://www.altlaw.com/
-----Original Message-----
From: Trevor Jordan [SMTP:trevor.jordan@rmit.edu.au]
Sent: Tuesday, October 07, 1997 11:01 PM
To: DANMAS@aol.com; triumphs@autox.team.net
Subject: Re: Audible buzzer
At 23:53 +1000 7/10/97, DANMAS@aol.com wrote:
>The turn signal indicator light in a TR6 is a very interesting circuit.
One
>side of the bulb is connected to the right hand turn signal lights, and
the
>other side is connected to the left hand turn signal lights. When, for
>example, the right hand turn signal is on, power is applied to the right
side
>lamps and the indicator bulb, and the indicator bulb finds a path to
ground
>through the left hand turn signal lamps. The opposite occurs when the left
>hand turn signals are on.
>
>As you can see, with this arrangement, the buzzer will only sound when you
>are using the side which the buzzer is connected to. When using the other
>side, there will be no voltage on the buzzer.
>
Well, who was responsible for that clever bit of design: Triumph or their
co-conspirators at Lucas?
A couple of possible solutions come to mind:
1. use two buzzers, one in each direction accross the indicator light
wiring - they are cheap, and although they are definitely polarity
dependent, they may not be damaged by the frequent application of reverse
potential (only time will tell - there was no warning on the packaging).
[Marketing point - if a buzzer fails, then only one direction of turn will
be affected.]
2. use a small bridge rectifier - also cheap, but it could be a bit messy
to make all those connections behind the dash and insulate them properly.
3. find a suitable polarity insensitive buzzer.
Since I have already purchased one buzzer, I will try that first to see if
it is compatible with the indicator lamp wiring. If it is, I will try 1 or
2 above. If not, I will pursue 3. Expect a progress report after the
weekend.
Trevor Jordan
74 TR6 CF29281U (no overdrive - but an overdrive light would be impressive,
or maybe a turbocharger light or an afterburner light!!!)
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