Isn't the 12VDC coming through the light bulbs. I don't see a potential for a short circuit. The circuit provides a ground path for the lights.

> To:
> Date: Fri, 27 Nov 2009 08:40:07 -0500
> From: dfs155@roadrunner.com
> Subject: [LML] Gear warning indicator
>
> Excuse me!! This looks to have at least two design faults.
>
> Problem 1: If the airspeed switch is closed and any one (or more) of the
> green "down and locked" lights are energized via the gear position switches,
> 12 volts will be applied thru one or more of the diodes to this "blinker"
> and it will try to operate - e.g., the 1000 mike capacitor will charge thru
> the 100 ohm resistor until the voltage reaches the relay pull-in voltage.
>
> Problem 2: Unfortunately, as soon as the capacitor charges sufficiently to
> pull in the relay, the relay contacts close and the 12 volts is shorted
> directly to ground. Hopefully, only blowing a fuse or popping a breaker, but
> effectively taking at least the gear light circuit down.
>
> Neat!
>
> Dan Schaefer
>
> PS: Stick the resistor on the other side of the relay contacts to at least
> solve the shorting - not sure what to do to keep this thing from blinking
> the lights when at least one gear leg is down and locked. But what do I
> know? I'm just a retired EE and things have a way of getting fuzzy in 10
> years!
>
> DS
>
>
> --
> I am using the free version of SPAMfighter.
> We are a community of 6 million users fighting spam.
> SPAMfighter has removed 631 of my spam emails to date.
> Get the free SPAMfighter here: http://www.spamfighter.com/len
>
> The Professional version does not have this message
>
>
>
> --
> For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html