Article
A 100 nH to 100 mH Single-Range Inductance Meter with LCD Readout
Coil Clinic
Here’s a portable instrument to measure self-inductance quickly and accurately. Coil Clinic is a one-stop, autoranging meter with microprocessor control — all you do is connect up the unknown inductor and read the value on the LCD.
Materials
Gerber file
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PCB
Extra info / Update
‘Low Battery’ is erroneously displayed when the battery voltage is sufficiently high. The problem is conveniently solved by replacing R2 (10 k) with a 56 k resistor.
Component list
Resistors
R1 = 100kΩ
R2 = 10kΩ
R3,R5 = 1kΩ
R4 = 1MΩ
R6 = 680Ω
P1 = 50kΩ preset
Capacitors
C1,C2,C3,C7 = 470nF
C4,C5 = 12pF
C6 = 4nF7
C8 = 22nF
Semiconductors
D1 = BAT85
IC1 = 78L05
IC2 = Atmega48-20PU (order code 060195-41)
IC3 = AD8099ARDZ
Miscellaneous
S1 = pushbutton, e.g. RA3FTL6 (Multimec)
X1 = 20MHz quartz crystal, low profile
Alphanumerical LCD module, 1x16 characters, HD44870 compatible (see text)
K2 = 14-way SIL pinheader
K3 = 6-way SIL receptacle strip (see text)
PCB, ref. 060195-1 from Elektor SHOP
Source and hex files for ATMega48, free download
R1 = 100kΩ
R2 = 10kΩ
R3,R5 = 1kΩ
R4 = 1MΩ
R6 = 680Ω
P1 = 50kΩ preset
Capacitors
C1,C2,C3,C7 = 470nF
C4,C5 = 12pF
C6 = 4nF7
C8 = 22nF
Semiconductors
D1 = BAT85
IC1 = 78L05
IC2 = Atmega48-20PU (order code 060195-41)
IC3 = AD8099ARDZ
Miscellaneous
S1 = pushbutton, e.g. RA3FTL6 (Multimec)
X1 = 20MHz quartz crystal, low profile
Alphanumerical LCD module, 1x16 characters, HD44870 compatible (see text)
K2 = 14-way SIL pinheader
K3 = 6-way SIL receptacle strip (see text)
PCB, ref. 060195-1 from Elektor SHOP
Source and hex files for ATMega48, free download
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