Velleman K4305 Assembly instructions

Total solder points: 186
Difficulty level:
Beginner 1o 2þ 3o 4o 5o Advanced

K4305

2 x 10 LED STEREO VU METER

• For instant visualization of audio signal levels.

• Easy hook up to a LINE level ( LOW input) signal source.

• For use with mixing panels, amplifiers, CD players, radio’s, ...

• A special input (HIGH INPUT) is provided, which allows direct con-

nection to a SPEAKER* output .

• DOT or BAR display mode selectable to suit your application.

• Attractive display window supplied, which can be used both horizontal

as vertical.

• If wanted, the unit can be calibrated by means of a trim potentiometer.

*NOT SUITED FOR CONNECTION TO HIGH POWER CAR STEREO
SYSTEM

Specifications:

• 2 X 10 LED’s

• BAR OR DOT MODE

• INDICATION RANGE: 0dB = 0.775mVrms.

-20dB, -10dB, -7dB, -5dB, -3dB, -1dB, 0dB, +1dB, +2dB, +3dB

• FREQUENCY RANGE: 20Hz tot 30KHz

• LOW INPUT FOR 0dB: 150mV to 6Vrms (47K)

• HIGH INPUT FOR 0dB: 1.5V to 60Vrms (470K).

• POWER SUPPLY: 10 to 15VDC / 250mA max.

• PCB DIMENSIONS 2X: 68X37mm

modifications reserved

PARTLIST H4305P-ED1

5%

1

2

3

4

5

6

7

8

9

A

B

1%

COLOR= 2… 5

4K7= ( 4 - 7 - 2 - B )

4K7= ( 4 - 7 - 0 - 1 - 1 )

I P E SF S DK N D GB F NL

CODICE

C

COLORE

O
D
E

CODIGO

DE

CORES

CODIGO

DE

COLORES

VÄRI

KOODI

FÄRG

SCHEMA

FARVE

KODE

FARGE

KODE

FARB

KODE

COLOUR

CODE

CODIFI­CATION
DES
COU-

LEURS

KLEUR

KODE

0

Nero Preto Negro Musta Svart Sort Sort Schwarz Black Noir Zwart

Marrone Castanho Marrón Ruskea Brun Brun Brun Braun Brown Brun Bruin

Rosso Encarnado Rojo Punainen Röd Rød Rød Rot Red Rouge Rood

Aranciato Laranja Naranjado Oranssi Orange Orange Orange Orange Orange Orange Oranje

Giallo Amarelo Amarillo Keltainen Gul Gul Gul Gelb Yellow Jaune Geel

Verde Verde Verde Vihreä Grön Grøn Grønn Grün Green Vert Groen

C
O
D
E

0

1

2

3

4

5

Blu Azul Azul Sininen Blå Blå Blå Blau Blue Blue Blauw

Viola Violeta Morado Purppura Lila Violet Violet Violet Purple Violet Paars

Grigio Cinzento Gris Harmaa Grå Grå Grå Grau Grey Gris Grijs

Bianco Branco Blanco Valkoinen Vit Hvid Hvidt Weiss White Blanc Wit

Argento Prateado Plata Hopea Silver Sølv Sølv Silber Silver Argent Zilver

Oro Dourado Oro Kulta Guld Guld Guldl Gold Gold Or Goud

6

7

8

9

A

B

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ASSEMBLY STEPS

Required tools to assemble the kit:

A small soldering iron of max. 40W.
Thin (1mm) solder, do not use any flux.
A small cutter to trim the excess wires.

1.

Mount the compo­nents against the
PCB surface and
carefully solder the
leads.

2.

Obtain cone- shaped,
shiny soldered joints
by heating the com­ponent leads suffi­ciently.

3.

This solder joint
results in a bad
connection.

4.

Trim the excess
wires up to the
level of the sol­der

• Careless assembly will certainly lead to troubles.

• Insert the part, oriented correctly, into its correct holes on the PCB.

• Mount the components in the correct order as stated in this manual.

• The component values in the diagram are for reference only. The val-

ues in this partlist are correct and must be followed.

• Use the boxes q to tick off your progress.

F Before starting to build, also read the general guidelines

3

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Assembly

Mount all components onto the PC boards (mount the two boards)

1. JUMPERS

q J1
q J2, mount for BAR mode, do

not mount for DOT mode.

BAR DOT

2. DIODES (Check the polarity)

D...

CATHODE

q D1: 1N4148
q D2: 1N4148
q D3: 1N4000… 1N4007

3. ZENER DIODES
(Check the polarity)

+3

+2
+1
0dB

-1

-3

-5

-7

-10

-20

+3

+2
+1
0dB

-1

-3

-5

-7

-10

-20

ZD...

CATHODE

q ZD1: 6,2V (6V2)

4

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4. ¼W RESISTORS

R...

q R1: 47K (4-7-3-B)
q R2: 47K (4-7-3-B)
q R3: 330 (3-3-1-B)
q R4: 10K (1-0-3-B)
q R5: 10K (1-0-3-B)
q R6: 2K2 (2-2-2-B)
q R7: 470K (4-7-4-B)

5. IC SOCKETS

(Check the position of the notch)

6. RESISTOR TRIMMERS

RV...

q RV1: 220K (250K)

7. CAPACITORS

C...

q C1: 220nF (0.22µF, 224)
q C2: 220nF (0.22µF, 224)

1

q IC1: 8P
q IC2: 18P

IC...

8. ELECTROLYTIC CAPACITOR

(Check the polarity)

C...

+

q C3: 47µF
q C4: 47µF
q C5: 47µF

5

_______________________________________________________________________________________________________________________________________________________

9. 1W RESISTORS

q R8: 68 (6-8-0-B)

R...

2mm

6

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10. MOUNT THE LEDs, BEND THE LEADS CAREFULLY
(Check the polarity)

LED

SOLDER

SIDE

PCB

COLOR = 2...5

q LD1: green (5)
q LD2: green (5)
q LD3: green (5)
q LD4: green (5)
q LD5: green (5)
q LD6: green (5)
q LD7: green (5)
q LD8: yellow (4)
q LD9: yellow (4)
q LD10: red (2)

LD...

CATHODE

7

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11. Insert the IC’s in the socket (Check the position of the notch)

1

PIN 1

IC...

q IC1: 741
q IC2: LM3916

Mount the units in a suitable housing or on a suitable panel:

12. Mounting possibility:

A. Make or search for suitable bracket:

8

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B. Make the holes in the housing or panel and mount the bracket:

7

15

7

4.5

Ø3.5

52

FRONTPANEL

BRACKET

60

10mm M3 COUNTERSUNK-HEAD BOLT

2...3mm FRONTPANEL

LOCK WASHER

M3 NUT

BRACKET

LOCK WASHER
M3 NUT

9

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C. Mount the PCB’s with spacers onto the bracket:

M3 NUT

LOCK WASHER

FRONTPANEL

15mm SPACER

15mm SPACER

2...3mm FRONTPANEL

SOLDER

SIDE

M3 NUT

LOCK WASHER

PCB

15mm SPACER

PCB

15mm SPACER

BRACKET

BRACKET

40mm M3 BOLT

40mm M3 BOLT

10

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Connect the unit to a suitable signal, this can be line level (LOW input) :

13. Connecting to a line level output (tuner, preamp, cd player… )
and connecting a power supply from 10 to 15VDC / 250mA max..

HIGH IN
LOW IN

LEFT

+

P4304

L

TAPE

OUT

R

FROM AUDIO AMPLIFIER

MAINS

MAINS

1N4007

12V/250mA

12V/250mA

1N4007

12V/250mA

1000uF/25V

HIGH IN
LOW IN

+

+

1000uF/25V

RIGHT

+

+

10...15VDC
POWER

SUPPLY

P4304

Connect the unit to a suitable supply voltage between 10VDC and
15VDC, this can also be a standard DC adapter. You can also build
your own power supply, see diagram. Use a 2x12V transformer, two
rectifier diodes and a electrolytic capacitor or use a single 12V trans­former with a bridge rectifier and a electrolytic capacitor.

11

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Connect the unit to a speaker output (HIGH input):

14. Connecting to a speaker level output and connecting a power
supply from 10 to 15VDC / 250mA max..

SPEAKER LEFT

INPUT (0)

SPEAKER RIGHT

-

+

+

-

FROM POWER AMPLIFIER

MAINS

MAINS

1N4007

12V/250mA

12V/250mA

1N4007

12V/250mA

1000uF/25V

+

+

1000uF/25V

HIGH IN
LOW IN

HIGH IN
LOW IN

LEFT

+

RIGHT

+

+

10...15VDC
POWER

SUPPLY

P4304

P4304

Connect the unit to a suitable supply voltage between 10VDC and
15VDC, this can also be a standard DC adapter. You can also build
your own power supply, see diagram. Use a 2x12V transformer, two
rectifier diodes and a electrolytic capacitor or use a single 12V trans­former with a bridge rectifier and a electrolytic capacitor.

12

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Connect the unit to a car radio:

15. Connecting to a speaker output from a regular car radio.

LEFT SPEAKER

RIGHT SPEAKER

+12V ANTENNE POWER OUT

CAR RADIO

L+
L-

R+

R-

HIGH IN
LOW IN

HIGH IN
LOW IN

LEFT

+

RIGHT

+

P4304

P4304

The 12VDC car battery power or car radio antenna output can be used
to supply the VU meter.

REMARK: Do not connect the unit to a high power car booster or car
stereo, this equipment uses isolated ground connection. The connection
to this kind of amplifier can cause permanent damage to the amplifier or
car radio!

• Adjust the units sensitivity according to your preference by means of
the trim potentiometer RV1

13

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