Velleman K4304 User manual

10 LED MONO VU METER
K4304
ILLUSTRATED ASSEMBLY MANUAL H4304IP-1
Total solder points: 93
Difficulty level: beginner 12345 advanced
Addavisualreadouttoyourexistingor
newequipment.

2
Features:
 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 connection 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.
Specifications:
 1 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 to 30KHz
 Low input for 0dB: 150mV to 6Vrms (47K)
 High input for 0dB: 1.5V to 60Vrms (470K).
 Power supply : 10 to 15VDC / 110mA max.
 PCB Dimensions : 68X37mm
 NOT SUITED FOR CONNECTION TO HIGH POWER CAR STEREO SYSTEM
Features & Specifications

3
Assembly hints
1. Assembly (Skipping this can lead to troubles ! )
Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully.
1.1 Make sure you have the right tools:
• A good quality soldering iron (25-40W) with a small tip.
• Wipe it oftenon a wet sponge or cloth, to keepit clean; then apply solder to the tip, togive it a wetlook. This is called ‘thinning’ and will
protect the tip,and enables youto make goodconnections. When solder rolls off the tip,it needs cleaning.
• Thin raisin-core solder. Do not use any flux or grease.
• A diagonal cutter to trim excess wires. To avoid injury when cutting excess leads, hold the lead so they
cannot fly towards the eyes.
• Needle nose pliers, for bending leads, or to hold components in place.
• Small blade and Phillips screwdrivers. A basic range is fine.
For some projects, a basic multi-meter is required, or might be handy
1.2 Assembly Hints :
⇒ Make sure the skill level matches your experience, to avoid disappointments.
⇒ Follow the instructions carefully. Read and understand the entire step before you perform each operation.
⇒ Perform the assembly in the correct order as stated in this manual
⇒ Position all parts on the PCB (Printed Circuit Board) as shown on the drawings.
⇒ Values on the circuit diagram are subject to changes.
⇒ Values in this assembly guide are correct*
⇒ Use the check-boxes to mark your progress.
⇒ Please read the included information on safety and customer service
* Typographical inaccuracies excluded. Always look for possible last minute manual updates, indicated as ‘NOTE’ on a separate leaflet.
0.000

4
Assembly hints
1.3 Soldering Hints :
1- Mount the component against the PCB surface and carefully solder the leads
2- Make sure the solder joints are cone-shaped and shiny
3- Trim excess leads as close as possible to the solder joint
REMOVE THEM FROM THE TAPE ONE AT A TIME !
AXIAL COMPONENTS ARE TAPED IN THE COR-
RECT MOUNTING SEQUENCE !

5
Construction
 D1 : 1N4148
 D2 : 1N4148
2. Diodes. Watch the polarity !
D...
CATHODE
 ZD1 : 6V2
3. Zenerdiode. Watch the
polarity !
 R1 : 47K (4 - 7 - 3 - B)
 R2 : 47K (4 - 7 - 3 - B)
 R3 : 330 (3 - 3 - 1 - B)
 R4 : 10K (1 - 0 - 3 - B)
 R5 : 10K (1 - 0 - 3 - B)
 R6 : 2K2 (2 - 2 - 2 - B)
 R7 : 470K (4 - 7 - 4 - B)
5. Resistors
R...
CATHODE ZD...
 IC1 : 8p
 IC2 : 18p
6. IC sockets. Watch the
position of the notch!
 J1
 J2, mount for BAR mode, do
not mount for DOT mode.
1. Jumper wires
+3
+3
+2
+2
+1
+1
0dB
0dB
-1
-1
-3
-3
-5
-5
-7
-7
-10
-10
-20
-20
BAR DOT
 D3 : 1N4007
4. Diode. Watch the polarity !
D...
CATHODE

6
 IC1 : UA741
 IC2 : LM3916
Construction
 C1 : 220nF (224)
 C2 : 220nF (224)
7. Capacitors.
11. IC’s. Watch the polarity !
C...
 R8 : 68 (6 - 8 - 0 - B )
10. 1W resistor
R...
2mm
 RV1: 220K
(Sensitivity)
8. Trim potentiometer
 C3 : 47µF

C4 : 47µF
 C5 : 47µF
9. Electrolytic Capacitors.
Watch the polarity !
C...
-

7
Construction
 Remark: Depending on your application, these LED’s can be mounted perpendicular
or parallel (see also points 13 and 14):
Perperdicular mounting : Parallel mounting :
12. MOUNT THE LEDs (Check the polarity)
PCB
SOLDER
SIDE
LED
13mm
SOLDER
PCB
SIDE
LED
 LD1 : green
 LD2 : green  LD3 : green  LD4 : green  LD5 : green  LD6 : green  LD7 : green  LD8 : yellow  LD9 : yellow  LD10 : red LD...
CATHODE

8
Ø3.5
52
60
7
4.5
Parallel mounting
13. PARALLEL MOUNTING (optional)
(A) Make the holes in the housing or panel (fig.1.0) :
(B) Mount the suitable spacers (fig. 2.0) :
6mm M3 COUNTERSUNK-HEAD BOLT
LOCK WASHER
10mm M3 SPACER
FRONTPANEL
2...3mm FRONTPANEL
10mm M3 SPACER
LOCK WASHER
Fig. 2.0
Fig. 1.0

9
6mm M3 COUNTERSUNK-HEAD BOLT
4mm M3 BOLT
2...3mm FRONTPANEL
10mm M3 SPACER
4mm M3 BOLT
PCB
LOCK WASHER
(C) Mount the PCB onto the spacers (fig 3.0) :
Fig. 3.0
Parallel mounting

10
14. PERPENDICULAR MOUNTING (optional)
Fig. 4.0
(A) Make or search for a suitable bracket :
(B) Make the holes in the housing or panel and
mount the bracket (fig. 5.0) :
Fig. 5.0
Perpendicular mounting
LOCK WASHER
M3 NUT
10mm M3 COUNTERSUNK-HEAD BOLT
BRACKET
FRONTPANEL
LOCK WASHER
M3 NUT
2...3mm FRONTPANEL
BRACKET

11
15mm SPACER
2...3mm FRONTPANEL
PCB
M3 NUT
LOCK WASHER
SOLDER
SIDE
20mm M3 BOLT
20mm M3 BOLT
BRACKET
BRACKET
15mm SPACER
LOCK WASHER
M3 NUT
FRONTPANEL
(C) Mount the PCB with spacers onto the bracket (fig. 6.0) :
Fig. 6.0
Perpendicular mounting

12
15. CONNECTION TO A SUITABLE SIGNAL
Connecting to a line level output (tuner, preamp, cd player… ) and connecting a power supply from
10 to 15VDC / 110mA max..
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.
Fig. 7.0
Connection
12V/150mA
12V/150mA
12V/150mA
MAINS
MAINS
FROM AUDIO AMPLIFIER
TAPE OUT
10...15VDC
1000uF/25V
+
1000uF/25V
1N4007
1N4007
+
SUPPLY
POWER
+
HIGH IN
LOW IN +K4304

13
12V/150mA
12V/150mA
12V/150mA
FROM POWER AMPLIFIER
MAINS
MAINS
SPEAKER OUT-
+
INPUT (0)
10...15VDC
1000uF/25V
1N4007
+
1000uF/25V
1N4007
+
POWER
SUPPLY
+
LOW IN
HIGH IN +K4304
16. CONNECTION TO A SPEAKER OUPUT
Connecting to a speaker level output and connecting a power supply from 10 to 15VDC / 110mA max.
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.
Fig. 8.0
Connection

14
17. CONNECTION TO A CAR RADIO
Connecting to a speaker output from a regular car radio.
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!
Fig. 9.0
Connection
-
+12V ANTENNE POWER OUT
CAR RADIO
SPEAKER OUT
+
LOW IN
+
K4304
HIGH IN
 Adjust the units sensitivity according to your preference by means of the trim potentiometer RV1

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18. PCB LAYOUT
PCB & Diagram
L
OW IN
GND
C1
220n
R1
47K
RV1
220K
R2
47K
UA741
IC1
+V
2
34
76
D1
1N4148
D2
1N4148
R3
330
+V
R4
10K
C3
47u
6V2
ZD1 C4
47u
5
4
SIG
RLO
6
RHI
REF
7
R6
2K2
R5
10K
ADJ
8
J1
DOT/BAR
+V
9
MODE
+V
3
2
V+
V-
LD2
GREEN
18
-10dB
LD3
GREEN
-7dB
17
LD4
GREEN
-5dB
16
LD5
GREEN
-3dB
15
LD6
GREEN
-1dB
14
LD7
GREEN
0dB
13
LD8
YELLOW
+1dB
12
LD9
YELLOW
+2dB
11
LD10
RED
+3dB
10
LD1
GREEN
-20dB
1
R8
68/1W
+V
+
GND
D3
1N4007
C5
47u
C2
220n
+V
IC2
LM3916
10...15VDC
R7
470K
H
IGH IN
J1 CLOSED = BAR MODE
J1 OPEN= DOT MODE
SENSITIVITY
modifications reserved
19. DIAGRAM

Modifications and typographical errors reserved
© Velleman Components nv.
H4304IP - 2004 - ED1
VELLEMAN Components NV
Legen Heirweg 33
9890 Gavere
Belgium Europe
www.velleman.be
www.velleman-kit.com
5410329 289898