- on Test & Measurement
- Published in issue 2/2003 on page 0
Autoranging Capacitance Meter
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 = 120?
R2 = 5k?6
R3 = 5M?6
R4 = 1k?
R5 = 39k?
R6 = 10k?
R7 = 470? 1W (see text)
P1 = 1M? 10-turn multiturn preset, vertical mounting
P2 = 1k? 10-turn multiturn preset, vertical mounting
P3 = 100? 10-turn multiturn preset, vertical mounting
P4 = 22k?
C1 = 47nF
C2,C7 = 100nF
C3,C4 = 4pF7
C5,C6 = 330nF
D1 = zener diode 5V6 1W
D2,D3 = 1N4148
IC1 = TLC555 (Texas Instruments), 3V555 or TS555 (Thomson)
IC2 = PIC16F84A-20/P, programmed, order code 020144-41
IC3 = 78L05
T1 = BC559B
BT1 = 9V PP3 (6F22) battery with clip-on connector
JP1 = 2-way pinheader with jumper
K1 = two 7-way socket strips, lead pitch 0.1 inch
K2 = 16-way boxheader
K3 = PCB solder terminals
S1 = on/off switch
X1 = 20MHz quartz crystal
LCD display, 2x16 characters, e.g., Trimods 1536, Farnell # 142-554
Length of 16-way flat cable with IDC socket
Enclosure: e.g., Pactec HPS and HPLS series, type HPS-9VB (28x53x91x146 mm), Farnell # 736-351, see also www.pactecenclosures.com
PCB, order code 020144-1
Disk, source code and hex files, order code 020144-11 or Free Download