- on Test & Measurement
- Published in issue 10/2003 on page 0
Minimalist Induction-Balance Metal Detector
A low-cost treasure hunter
CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor GREEN and GOLD members can exclusively download these files for free as part of their membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service.
Elektor recommends its business partner Eurocircuits as the company of choice for its own prototypes and volume production in selected cases.
R1 = 2k?7
R2 = 470?
R3,R5,R6 = 100k?
R4 = 4k?7
R7 = 1k?
R8,R9 = 100?
P1 = 50k? potentiometer, linear
P2 = 2k?5 potentiometer, linear
C1 = 100µF 25V radial
C2 = 47µF 10V radial
C3 = 10nF
C4, C6 = 10µF 10V radial
C7-C11 = 100nF
D1 = 1N4001
IC1,IC2 = 555C, TLC555, 7555 (CMOS)
IC3 = TL071 CP, TL081 CP
IC4 = (LM)317T (in TO220 case )
K1, K2 = 3-way PCB terminal block, lead pitch 5mm
BZ1 = passive (ac) piezo buzzer
PC1,PC2 = solder pins
12V battery or battery block (8 AA penlight cells)
36-30 SWG (0.2-0.3mm dia.) enamelled copper wire, 2 x 50m
Enclosure: Bimbox 5004-14 or Hammond 1590B (109x58x25mm)
5m symmetrical screened microphone cable (two wires with common screening)
PCB, order code 020290-1