Page 95 - 15 Dangerously Mad Projects for the Evil Genius

74 15 Dangerously Mad Projects for the Evil Genius

WARNING! You can buy laser modules from standard
component suppliers like Farnell and RS, but they
You should always take certain precautions when tend to be very expensive. So look online, where
using lasers:
they should cost no more than two or three dollars.
■ Never shine a laser into your eyes or anyone
The mirrors were bought in a pack of six from a
else’s.
hobby and craft retailer.
■ Resist the temptation to check if a laser is on by
peering into it. Always shine it onto a sheet of The plastic packing material should allow light
paper or some other light surface. to pass through it, but it will diffuse the light like
frosted glass.

In addition, you will also need the following
What You Will Need
tools, shown in the Toolbox.
You will need the following components to build Figure 7-2 shows the schematic diagram for this
this project. project.

P A RT S BIN
Part Quantity Description Source
Laser 1 5 mW red laser LED module eBay

R1 1 1M variable resistor Farnell: 1629581
R2 1 1M 0.5-W metal film resistor Farnell: 9339809
R3 1 270 0.5-W metal film resistor Farnell: 9340300

R4 1 100 0.5-W metal film resistor Farnell: 9339760
T1 1 NPN phototransistor (visible light) Farnell: 1497673
D1 1 5mm red LED Farnell: 1712786
T2 1 2N7000 Farnell: 9845178
Power socket 1 2.1mm power socket Farnell: 1217038

Power supply 1 12V 0.5A (or more) power supply Farnell: 1279478
with 2.1mm connector

S1 1 DPDT on-off-on toggle switch Farnell: 9473530
Box 1 Small plastic project box Farnell: 301243
Buzzer 1 Piezo buzzer Farnell: 1192513
Knob 1 Farnell: 1441137

Mirrors 3 Small mirrors Craft shop
Adhesive putty
Diffuser Expanded-plastic packing material, Recycling
1
about ⁄2-inch square (10mm)
Cable 6 feet Twin core flex Hardware store
(1800mm)