Howdy,
I had a few MGers from the list requesting the how-to stuff for the
flashing LED dumb thief deterrent.
The easiest circuit is built using an LED flasher chip from Radio Shack.
The simple design instructions are on the package (even easier than using
the 555 timer)
I also used a 7805 voltage regulator to drop the 12Vdc to 5Vdc for
circuit operation (may not be needed for the flasher circuit) (again, simple
design instructions on package).
An inline power switch was used so I could turn the flashing LED off
while driving. It would be easy to add an ignition-on decector (relay or
digital logic) to automatically switch the circuit off while the car is
running.
My MGB dash had several holes drilled by the DPO (one descrete hole
at the bottom of the dash would do or maybe even something clipped to the
bottom for a no-hole installation). I used a convenient one at the bottom
of my dash to insert the LED and plastic retainer. The circuit card was
tucked up and tied behind the dash.
PARTS LIST (all available from Radio Shack):
7805 Voltage Regulator (12Vdc in 5Vdc out)
LED Flasher IC
Red LED and plastic retainers
A couple of resistors and capacitors (see LED Flasher IC package for values)
Toggle switch
A small piece of proto-board
Wire
Solder
Beer
I can check Radio Shack this weekend if anyone needs part numbers or
any more information.
There are those out there who will pooh pooh this idea saying it's
an old or smart thieves wont't buy it or yadda yadda yadda.... Hey it works
on dumb ones! It may even save your top from being slashed when the doors
are unlocked or other such moronic offenses perpetrated by the gray-matter
challenged.
Cheers,
R. John Fagelund
'65 MGB (with flasher)
'66 BGT (will get flasher)
|