housing RCA jack. Wrap the excess cable in spiral
fashion along the length of the metal detector’s shaft and
secure with electrical tape. This will keep the cable
from moving and causing a subsequent change in stray
and PIC BASICPRO™!
A Three-Day class of programming
and hardware experiments designed
Learn to Program and Control:
to quickly bring you up to speed
LED and LCD Displays
using PICs and PIC BASICPRO. Relays and Solenoids
DC, Servo, and Stepper Motors
LM34 and DS1620 Temp Sensors
Photo (light) Sensors
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Timers, Counters, Interrupts
Visual Basic Interfaces
Innovative Ideas in Electronics Design
2007 Class Schedule
Austin, TX, April 17-19
Albuquerque, NM, June 5-7
Minn. MN, Aug. 7-9
San Diego, CA, Oct. 9-11
San Jose, CA, Dec. 4-6
Check our web site for more details.
Phone (800) 442-8272
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2) Plug the ceramic earphone into J2.
3) Turn the volume control completely clockwise.
4) Attach the two 9V batteries to the battery snaps and
install the batteries into the holders.
5) Verify that S1 is in the On position.
You should hear a tone from the earpiece. The pitch
at the earphone should increase when the search coil
approaches a metal object. To obtain this result, make
sure that no metal object is near the search coil and then
turn C6 clockwise so that the pitch is a high tone, followed
by a decreasing tone until the earphone is silent.
Next, rotate C6 counter-clockwise until a frequency of
approximately 2 kHz is reached. As mentioned before, if
you are unable to tune the unit as specified, try reducing
the value of C8.
Now that the tone has been set, attach the lid to the
case with the four screws provided. If the metal detector
does not balance properly, you may want to decrease
the main shaft length to less than 33”. Photo 8 shows the
finished metal detector.
After the unit has been tested and completely
assembled, it’s time to look for coins and jewelry! Good
places to find coins at shallow depths are under the
swings at a playground and below bleachers. For very
large metal objects at close distances, the output pitch
of the metal detector may be higher than physically
audible. Happy hunting with your four transistor metal
1) R. Dean Straw, N6BV, The ARRL Handbook, “Calculating Practical
Inductors,” 1999, p. 6-22, The American Radio Relay League.
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Development Tools for PIC® MCUs
microEngineering Labs, Inc.
Phone: (719) 520-5323
Fax: (719) 520-1867
Colorado Springs, CO 80960
USB Programmer for PIC® MCUs
$89.95 (as shown)
low-voltage ( 3.3V)
98, Me, NT,
XP, and Vista.
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Includes Programmer, Software, USB Cable,
and Programming Adapter for 8 to 40-pin DIP.
starting at $59.95
LAB-X Experimenter Boards
Available for 8, 14, 18, 28,
and 40-pin PIC® MCUs
2-line, 20-char LCD Module
9-pin Serial Port
Full Schematic Diagram
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PICPROTO™ Prototyping Boards
Double-Sided with Plate-Thru Holes
Circuitry for Power Supply and Clock
Large Prototype Area
Boards Available for Most PIC® MCUs
Documentation and Schematic
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BASIC Compilers for PICmicro®
Easy-To-Use BASIC Commands
PICBASIC™ Compiler $99.95
BASIC Stamp 1 Compatible
Supports most 14-bit Core PICs
Built-In Serial Comm Commands
PICBASIC PRO™ Compiler $249.95
Supports most PICmicro® MCU Families
Direct Access to Internal Registers
Supports In-Line Assembly Language
Interrupts in PICBASIC and Assembly
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Source Level Debugging
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