
MINEFIELD
INSTRUCTION
SHEET
Price - Stock No 20
Layout
The objective of the Maze is to find a safe path from the IN arrow to the OUT
arrow. The safe path is indicated by a GREEN LED, and the RED LED indicates
disaster. There is a buffer zone mostly - but not always- between the red and
green zones. The buffer zone is indicated by the ORANGE LED. The rule that
applies is that you can move forwards or backwards, sideways and diagonally, but
only one step at a time. If you wish you could connect a buzzer or construct a
sound effects project and connect them into the Orange and the Red circuits.
Construction
- Set out the grid pattern at 10mm intervals, and mark
suitablepositions for the three LEDs and the battery tamer holding screw. You
will also need a small hole for the black lead of the battery snap to feed
through.
- Drill three holes D6.35mm (1/4 inch) and push the LED
Mounts into them. Push the LEDs from the under-side into the mounts, but make
sure that the SHORT LEGS are all to the grid side. Cut a short piece of wire
from the roll in your Kit and lie it along the short legs, soldering the wire
to each short leg. Take the 390R resistor and solder one leg to the wire
joining the LEDs.
- Drill a small hole and feed the black lead of the
battery snap through. Solder this lead to the free leg of the resistor. This
means that the one resistor will meter the current to all three LEDs, on a
common 0 Volt rail (or earth if you like). For a 9 Volt supply, a 390 OHM
resistor will allow around 20 milliamps of current to flow through the LEDs.
(OHM's Law is used to calculate this). This is the specification for LEDs.
- Strip the insulation from each end of the coloured
wires and solder one end of each to long leg of the matching colour LED.
- Drive flat-head nails through the plywood at each of
the points of the grid.
- Design your maze and mark the path of the red track.
- Using long-nose pliers wrap the end of the wire
tightly round the first nail. Lie the wire in and out of successive nails in
the path, wrapping it right round every 3rd or 4th nail to keep it tight. Try
to ensure that the wire touches each nail. Repeat this process for each of the
Orange and Green paths.
- Solder the free ends of the coloured wires to their
respective path wires.
- Solder the alligator clip to the Red wire of the
battery snap, and attach the battery tamer with its screw.
- Connect a battery and test that a LED lights up when
each nail is touched with the alligator clip. For any that don't light push
the wire against the nail. For troublesome ones solder the wire to the
individual nail.
- Test your maze for its safe path.
- Cut some coolite for a backing piece and gently tap
the nails so the plywood firms down evenly onto the coolite.
- Mark the ENTRY and EXIT and your maze is ready.
Tread lightly
Contact CdS electronics
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