Continuity buzzer

Continuity buzzer

Post by Doug » Thu, 04 Sep 1997 04:00:00



Anyone have plans or a detailed description for adding a coontinuity
buzzer and/or light for my controller (not the standard estes, it's a
home-built one) I kinda know what they do, but would love detailed
instructions or plans.

Thanks

 
 
 

Continuity buzzer

Post by Cochran, T » Fri, 05 Sep 1997 04:00:00


Quote:

> Anyone have plans or a detailed description for adding a coontinuity
> buzzer and/or light for my controller (not the standard estes, it's a
> home-built one) I kinda know what they do, but would love detailed
> instructions or plans.

> Thanks

The idea is to put the light/buzzer in series with the ignitor, and
shorting around the light/buzzer with the launch switch.  The light/buzzer
has to limit the current through the ignitor to 100 millamps max.
(assuming you're not involved with flashbulbs or other very low current
ignition devices).  

A small lightbulb or a piezoelectric buzzer is OK; bigger bulbs and
mechanical buzzers draw too much current.

--tc

My opinions only.
To reply by email please read and translate my email address.

 
 
 

Continuity buzzer

Post by Cochran, T » Fri, 05 Sep 1997 04:00:00


Quote:



> >> Anyone have plans or a detailed description for adding a coontinuity
> >> buzzer and/or light for my controller (not the standard estes, it's a
> >> home-built one) I kinda know what they do, but would love detailed
> >> instructions or plans.

> >> Thanks

> >The idea is to put the light/buzzer in series with the ignitor, and
> >shorting around the light/buzzer with the launch switch.  The light/buzzer
> >has to limit the current through the ignitor to 100 millamps max.
> >(assuming you're not involved with flashbulbs or other very low current
> >ignition devices).

> I picked up a small piezo-buzzer at RadioShack that draws 25ma max.
> It's in a small white plastic casing, maybe just over 1/2" square and
> 1/4" thick.  It's complete with wire leads and oscillator circuit.
> Not deafening (a good thing), but can be heard for 10-15 feet.

> I just wish it cycled on-off like a back-up beeper.
> ---

THere are fairly simple circuits that could be developed for this
purpose.  Be sure NOT to use something like an automobile flasher in
series with the ignitor, which will draw too much current in one of its
two states to be safe.

I have a big mechanical buzzer and a yellow light that I put out at the
pad that turn on when the key switch is thrown (using power not through
the ignitor).  The purpose is to 1) make darn sure I know when the power
is on! and 2) Alert folks of an impending launch (as in large parks).

I use a lighted pushbutton launch switch, and the light is the continuity
checker.  So, if I turn the key and the button doesn't light, I don't
expect to launch.

--tc

My opinions only.
To reply by email please read and translate my email address.