ESR

idealcapacitor

reactive part XC =2πf .C

1

012022 - 11

C

SQ

QDR

1M

1M

1M

012022 - 12

2k2

2k2

2k2

2k2

1M

ES

R

XC = 0

ESR =10Ω

+5V

0

1.255V1.244V

0

1.255V1.244V

0

1.255V

0

11mV0

1.244V0

+5V

0

C.u.T. ≈ 100µF

16 Elektor Electronics 9/2002

C

SQ

QDR

1M

1M

1M

012022 - 13

2k2

2k2

2k2

2k2

1M

ES

R

XC = 15

ESR =0Ω

+5V

0

0

50mV

+5V

0

0

50mV

0

50mV

0 50mVpp

0VDC

0

50mV

C.u.T. ≈ 100nF

VARITRONIX VI-302 DPRC

LCD1

BC4

ARR

32

G3

31

F3 E3

10

D3

11

C3

29

B3

30

A3

27

G2

26

F2

13

E2

14

D2

15

C2

24

B2

25

A2

23

G1

22

F1

17

E1

18

D1

19

C1

20

B1

21

A1

40BP

BP

39PL

38 28

P3

12

P2

16

P1

9

1

3

2

8

+5V

R28

22

k

1k

P5

C16

100n

C14

100p

C18

100n

C17

220n

R30

10

0k

R27

10

0k

C8

10n

ICL7106REF HI

REF LO

IN LO

IN HI

OS

C 1

OS

C 2

OS

C 3

C R

EF

C R

EF

BU

FF

COMM

TEST

IC9

F 3

PO

L

INT

A/Z

A1

B1

D1

E1F1G1

12

A2

11

B2

10

C2

D2

14

E2

13

F2

25

G2

23

A3

16

B3

24

C3

15

D3

18

E3

1722

G3

19

AB

20

21BP

30

31

26

36

35

40 39 38 27282932

37

3334

C1

5428679

1V

V

3

R29

1M

IC3.D

12

11 10

IC3.B

5

4 3

IC3.A

13

1 2

IC3.C

6

8 9

6

5

7IC4.B

R14

10k

TPAR25

100k

R24

22

k

TPB

R15

1M

R16

1M

R26

1k

R22

1M

C15

1n

2

3

1IC4.A

C7

220n

R19

10

k

5 6

4

IC6.B =1

2 1

3IC6.A

=1

R20

1M

R21

47

Ω

R18

10

k

100k

P2

R17

10

k

+5VD4

1N4002

D3

R10

56Ω

R12

56Ω

R9

56Ω

R11

56Ω

R7

2k

2

R8

2k

2 2x

D1

1N4002

D2

2x

R3

1k8

R6

2k2

IC2.A

3C

4

S

2D

1

R5

6

1kP3

+5V

IC6

14

7

+5V

+5V

IC2.B

11C

10

S

12D

13

R9

8

8

910

IC1.C

&5

64

IC1.B

&1

23

IC1.A

&

5kP4

C1

180p

R1

10

k

R2

4k7R23

10

0k

S1

+5V

IC8

2

3

1

8

4

R31

10

k

R5

33

k

R13

10

k

R4

22

k

+5V+9V

C5

10µ16VC4

10µ16V

C3

10µ16V

+5V

LM2931-5,0IC5

C2

100n

C6

100µ16V

BT1

9V

+5V

+9V

LM358

TPC TPD

ICL7660

BOOST

IC7

VOUTOSC

C–

C+

LV

8

3

2

5

4

1

6

7

Cx

IC1

14

7

C13

100n

+5V

C10

100n

C9

100n

IC4

8

4

IC2

14

7

C12

100n

+5V

IC3

14

7

C11

100n

+5V

+5V

IC2 = 74ACT74IC3 = 74VHC4066

- 5V

- 5V

- 5V

- 5V

IC4 = LF412

IC1 = 4093

BATTU

BATTU

MT

ZERO ADJUST

ADJUSTSYMMETRY

TESTCAP. SHORT

MT

FREQ.ADJUST

P1

5kMT

IC6 = 4070

LOBATT

+9V

0

C D

A B

012022 - 14

(C) ELEKTOR

012022-1

BT1

C1

C2

C3

C4

C5

C6

C7

C8C9

C10

C11

C12

C13

C14

C15

C16

C17

C18

D1D2

D3D

4

H1

H2

H3

IC1

IC2

IC3

IC4

IC5

IC6

IC7

IC8

IC9

LCD

1

P1

P2

P3

P4 P

5

R1

R2

R3

R4

R5

R6

R7R8

R9R10

R11

R12

R13

R14

R15

R16

R17R18

R19

R20

R21

R22

R23

R24

R25

R26

R27

R28

R29

R30

R31

S1

T

DC

T

BA

TPD

TPC

TPB

TPA

+9V0

01

20

22

-1(C

) ELE

KTO

R0

12

02

2-1

COMPONENTS LIST

Resistors:R1,R13,R14,R17,R18,R19,

R31 = 10kΩR2 = 4kΩ7R3 = 1kΩ8R4,R24,R28 = 22kΩR5 = 33kΩR6,R7,R8 = 2kΩ2R9-R12 = 56ΩR15,R16,R20,R22,R29 = 1MΩR21 = 47ΩR23,R25,R27,R30 = 100kΩR26 = 1kΩP1,P4 = 5kΩ multiturn preset,

vertical mounting, side adjust(Bourns 3266X, Farnell #347-747)

P2 = 100kΩ multiturn preset, verticalmounting, side adjust (Bourns3266X, Farnell #347-784)

P5 = 1kΩ multiturn preset, verticalmounting, side adjust (Bourns3266X, Farnell #347-723)

P3 = 1kΩ preset, horizontalmounting

Capacitors:C1 = 180pFC2,C9-C13,C16,C18 = 100nFC3,C4,C5 = 10µF 10V radialC6 = 100µF 16V radialC7 = 220nFC8 = 10nF

C14=100pFC15 = 1nFC17 = 220nF

Semiconductors:D1-D4 = 1N4002IC1 = 4093IC2 = 74ACT74 PCIC3 = 74VHC4066IC4 = LF412-CNIC5 = LM2931-5,0IC6 = 4070IC7 = ICL7660IC8 = LM358-NIC9 = ICL7106-CP

Miscellaneous:LCD1 = 3.5 Digit LCD with LO-

BATT indicator, e.g., Varitronix VI-302 DPRC (Farnell #478-660)

S1 = pushbutton, 1 make contactBattery holderOn/off switch2 miniature probes, e.g., Hirschmann

PRUF1 (Farnell #523-483)Length of 2-core screened cableABS enclosure with LCD window and

battery compartment, e.g.Multicomp type BC4, (Farnell #645-758)

40-pin IC socket cut in half (see text)PCB, order code 012022-1

Probe 1

max. 0.5 m

A

B

Probe 2C

D