K7102 Metal Detector
Product Information:
The product is a metal detector with the model number K7102. It
is designed to help users avoid drilling into electric cables, gas
pipes, water pipes, or central heating pipes while drilling holes
in walls. The metal detector can detect metal objects in walls,
ceilings, and floors, and it has a detection range adjustable up to
8cm/3.1 inches. The device is powered by a 9V battery and has a
power consumption of 30mA maximum. It features a push-button
operation and an LED indicator that lights up when a metal object
is detected nearby. The product dimensions are 55x64mm/2.2×2.5
inches.
Product Usage Instructions:
1. Before starting the assembly process, make sure you have the
right tools, including a good quality soldering iron (25-40W) with
a small tip, thin raisin-core solder, a diagonal cutter, needle
nose pliers, small blade and Phillips screwdrivers.
2. Carefully read the assembly hints provided in the manual to
ensure a successful assembly.
3. Mount the components against the PCB surface and solder the
leads. Make sure the solder joints are cone-shaped and shiny.
4. Trim excess leads as close as possible to the solder joint
using a diagonal cutter.
5. Begin the construction process by following the instructions
for winding the coils. The coil consists of two windings around the
supplied ferrite core. Use thin double-sided sticky tape and
ordinary sellotape to hold down the windings.
6. Proceed with the construction and connection of other
components such as diodes, resistors, transistors, and trim
potentiometers. Pay attention to the polarity of diodes and zener
diodes.
7. Once the assembly is complete, connect a 12VDC buzzer (not
included) to the designated connection point on the PCB if
desired.
8. Insert a 9V battery into the power supply slot of the metal
detector to activate the device.
9. To use the metal detector, press the push button and move it
close to the wall, ceiling, or floor. The LED indicator will light
up if a metal object is detected in the vicinity.
10. Adjust the detection range using the adjustable feature of
the metal detector, up to a maximum of 8cm/3.1 inches.
Total solder points: 47 Difficulty level: beginner 1 2 3 4 5 advanced
METAL DETECTOR
K7102
Avoid dhisoalessteirnswwahllesn…drilling
ILLUSTRATED ASSEMBLY MANUAL
H7102IP
Features & Specifications
To come up against an electric cable while drilling a hole in a wall can have catastrophic consequences. Likewise, drilling into gas, water pipes or central heating pipes can be extremely hazardous. With a handy metal detector it can now be determined beforehand whether there are metal objects to be found in a wall, ceiling or floor. An LED indicates if a metal object is in the vicinity.
Specifications:
Avoid disasters when drilling holes in walls Locate pipes, cables, metal studs, … Great project for novices Your own unique application Push button operation
Features:
Detection range adjustable up to 8cm/ 3.1″ Power supply : 9V battery Power consumption : 30mA max. LED indicator 12VDC-buzzer connection (buzzer not included) Dimensions : 55x64mm / 2.2″x2.5″
2
Assembly hints
1. Assembly (Skipping this can lead to troubles ! ) Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully.
1.1 Make sure you have the right tools: A good quality soldering iron (25-40W) with a small tip. Wipe it often on a wet sponge or cloth, to keep it clean; then apply solder to the tip, to give it a wet look. This is called `thinning’ and will protect the tip,
and enables you to make good connections. When solder rolls off the tip, it needs cleaning. Thin raisin-core solder. Do not use any flux or grease. A diagonal cutter to trim excess wires. To avoid injury when cutting excess leads, hold the lead so they cannot fly towards the eyes. Needle nose pliers, for bending leads, or to hold components in place. Small blade and Phillips screwdrivers. A basic range is fine.
0.000
For some projects, a basic multi-meter is required, or might be handy
1.2 Assembly Hints : Make sure the skill level matches your experience, to avoid disappointments. Follow the instructions carefully. Read and understand the entire step before you perform each operation. Perform the assembly in the correct order as stated in this manual Position all parts on the PCB (Printed Circuit Board) as shown on the drawings. Values on the circuit diagram are subject to changes, the values in this assembly guide are correct* Use the check-boxes to mark your progress. Please read the included information on safety and customer service
* Typographical inaccuracies excluded. Always look for possible last minute manual updates, indicated as `NOTE’ on a separate leaflet.
1.3 Soldering Hints :
1- Mount the component against the PCB surface and carefully solder the leads
2- Make sure the solder joints are cone-shaped and shiny
3- Trim excess leads as close as possible to the solder joint
3
REMOVE THEM FROM THE TAPE ONE AT A TIME !
DO NOT BLINDLY FOLLOW THE ORDER OF THE COMPONENTS ONTO THE TAPE. ALWAYS CHECK THEIR VALUE ON THE PARTS LIST!
Construction
1. Coils
The coil consists of two windings around the ferrite core supplied.
In order to facilitate winding, thin double sided sticky tape can be stuck to the ferrite core, each winding can be held down using ordinary sellotape.
Both windings must be wound in the same direction (see fig 1.0)
Winding L1 = 120 turns (this winding can be marked with a sticky label)
Winding L2 = 43 turns.
Ø8mm a
L1
120T
2. Diode. Watch the polarity !
D1 : 1N4148
D…
CATHODE
3. Zenerdiode. Watch the polarity !
ZD1 : 3V9
CATHODE
ZD…
MAKE SURE TO SCRAPE OFF THE
LACQUER!
b c L2
43T
d
Fig. 1.0
Cu 0.3mm
5
Construction & connection
4. Resistors
R…
6. Transistors.
T1 : BC547B T2 : BC547B T3 : BC547B
8. Trim potentiometers
RV1 : 2K5 RV2 : 100
R1 : 330 R2 : 470 R3 : 470 R4 : 2K7 R5 : 10K
(3 – 3 – 1 – B) (4 – 7 – 1 – B) (4 – 7 – 1 – B) (2 – 7 – 2 – B) (1 – 0 – 3 – B)
5. Capacitors.
Choose C1 :
C…
C1 : 1n2 (122)
C1 : 3n3 (332)
Experiment for best result
C2 : 47nF (473)
7. LED. Watch the polarity!
LD1 : 5mm RED
9. Push button
SW1
CATHODE
LD1
6
10. Assembly
Connect the battery terminal to the point marked “+” (red) and “-” (black), see figure 2.0.
Black
Assembly
Fig. 2.0 Red Connect the windings to their respective points marked with a, b, (L1) and c, d (L2), see figure 3.0.
Fig. 3.0
MAKE SURE TO SCRAPE OFF THE
LACQUER!
7
Test
11. Test & final adjustments
1. Connect a 9V battery to the battery holder. 2. Go to a place where NO metal object is known to be in the vicinity. 3. Turn preset RV1 fully clockwise. 4. Turn RV2 fully anti-clockwise. 5. Depress the push button and hold it in during the final adjustments. 6. Turn RV1 anti-clockwise until the LED goes out. All further remaining adjustments are now concerned with RV2 only. To set to maximum sensitivity: turn RV2 until the LED is weakly lit. When the detector now comes into the vicinity of a metal object, the LED will be more brightly lit. This gives an indication of the distance and/or the size of the metal object.
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PCB
12. PCB layout.
9
Diagram
13. Diagram
1n2* 3n3
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VELLEMAN NV Legen Heirweg 33
9890 Gavere Belgium Europe www.velleman.be www.velleman-kit.com
VELLEMAN NV Legen Heirweg 33, B-9890 GAVERE
Belgium (Europe)
Modifications and typographical errors reserved © Velleman nv. H7102IP’1 (rev.4) – 2014
5 410329 289683
Velleman – Wholesaler and developer of electronics
