500mA

POWER ON

START

100nF

1000uF/25V

1000uF/63V

GND

GND

100nF

330/3W

7805T

LM317T

L

M

3

3

4

100nF

100uF/10V

P

O

W

E

R

(

g

re

e

n

)

2

2

0

100nF

100uF/50V

R

U

N

(

re

d

)

2

k

1

0

k

4

,7

k

10*

U DC Voltmeter (max20V)

1

M

2

k

100nF

F1

1

3

2

S1

2

3

1

S2

2

3

1

TR1

6

5

4

1

8

7

A

C

1

A

C

2

-

+

B1

A

C

1

A

C

2

-

+

B2

C1

C2

C3

C4

R1

VI

1

2

VO

3

IC1

GND

IC2

ADJ

IN

OUT

2

3

1

IC

3

C5

C6

L

E

D

1

R

2

C7

C8

L

E

D

2

R

3

R

4

A

E

S

R

5

*

X2

X3

X

4

R6

SV1-1 SV1-2

1

2

P1

R

7

R

8

DZ

C9

+

+

V

+

V

-

R

+

+

V

230V AC

230V AC

50V AC

15V AC

Up= +5V (Voltmeter P1 supply)

Uz= +40V DC

to Uz= +40V DC

I=10mA

TEST CONNECTOR

Zener Diode

Udz max=40V, Idz=10mA

* - choose R6 resistance to set I=10mA

R7 and R8 are Voltmeter P1 internal resistors

* - R5 setting determines Uz=40V DC

Electronic LED Voltmeter