MAGNETO TIMING LIGHT Plans

[Roger]

I am looking for plans to build a Mag timing light with the buzzer that
changes pitch. I remember seeing plans in a Magazine. Maybe Sport Aviation.

Roger @MD43 C150E

[Darrel Toepfer]

Roger wrote:

> I am looking for plans to build a Mag timing light with the buzzer that
> changes pitch. I remember seeing plans in a Magazine. Maybe Sport Aviation.

From my reply to your post in rec.aviation.piloting:

http://www.rst-engr.com/kitplanes/KP9910/KP9910.htm

Not sure about the pitch changing buzzer though...

[Roger]

Thanks,

This is a big help.

Roger



"Darrel Toepfer" > wrote in message
...
> Roger wrote:
>
>> I am looking for plans to build a Mag timing light with the buzzer that
>> changes pitch. I remember seeing plans in a Magazine. Maybe Sport
>> Aviation.
>
> From my reply to your post in rec.aviation.piloting:
>
> http://www.rst-engr.com/kitplanes/KP9910/KP9910.htm
>
> Not sure about the pitch changing buzzer though...

[nrp]

Roger wrote:
> I am looking for plans

I made a mag timer from an old transistor radio - one that had a 4 ohm
speaker. I connected two light test leads to the speaker voice coil
terminals & connected two more light leads to the radio output
transformer. The leads were commoned into their respective pair at two
remote alligator clip leads that could be attached to the magneto
terminal and ground. Tune in a noisy station & the sound can be
clearly heard only when the mag points are open. The change in sound
level (with Slick mags at least) is dramatic as the ponts close and
open.

I electrically "banged" the thing with the impulse many times without
effect, although I suppose a pair of back-to-back diodes back at the
transformer output would protect the radio circuitry under more trying
circumstances.

Jim Weir's RST thing below is more elegant but are the circuit boards
still available?

[[email protected]]

The transistor radio for mag timing is really cool. Here's another
simple idea:

Drive the magneto from a 50 ohm output audio oscillator. The resonant
frequency of the coil and capacitor is around 1kHz. You can hear
the note from the mag coils.

When the points are open, you can tune for resonance by listening. It
will be the loudest then.

When the points are closed, the note will go away.

Takes an oscillator that will do about 5v into 50 ohms or you will have
trouble hearing it.

Bill Hale