Rangkaian VU meter | Audio level Meter

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Rangkaian VU meter is one of the monitor to see a top-level audio systems. VU meter display uses LED as its quick response time, operate at low voltage and small current, so kompatible with a series of integrated design.

Rangkaian VU meter using the IC LM3915N which can control up to 10 LED. There are 10 fruit komparator that compares the input voltage level of the voltage reference (pin 6). In the IC has a reference voltage source is available so that you no longer need a reference voltage source from the outside.

To increase the voltage reference can be made with the setting VR2. Voltage reference that has been raised is not sensitive to changes in temperature and voltage portion. Reference voltage is used to control the voltage divider in the IC.

Rangkaian VU meters this series is quite simple, 1 IC and a few other supporting components. This series led the 10, the input voltage is 12V to 20 V but usually menggunkan voltage 12 Volt.

Skema rangkaian Vu meter

after a rangkaian of vu meters connected to the audio brace, brace maximize the volume of the audio, setting vr 10k so all led u.

Rangkaian Pendeteksi|Sensor Ketinggian Level Air

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This is the circuit diagram of a simple Water level detection (Pendeteksi|Sensor Ketinggian Level Air) for home and industries. In fact the the level of any conductive non corrosive liquids can be measured using this circuit. Pendeteksi|Sensor Ketinggian Level Air is based on 5 transistor switches.Each transistor is switched on to drive the corresponding LED , when its base is supplied with current through the water through the electrode probes.

One electrode probe is (F) with 6V AC is placed at the bottom of tank. Next probes are placed step by step above the bottom probe. When water is rising the the base of each transistor gets electrical connection to 6V AC through water and the corresponding probe. Which in turn makes the transistors conduct to glow LED and indicate the level of water. The ends of probes are connected to corresponding points in the circuit as shown in circuit diagram. Insulated Aluminum wires with end insulation removed will do for the probe. Arrange the probes in order on a PVC pipe according to the depth and immerse it in the tank. AC voltage is use to prevent electrolysis at the probes. So this setup will last really long. I guarantee at least a 2 years of maintenance free operation.That’s what I got and is still going.

Skema Rangkaian Sensor Ketinggian Level Air

list Components of Water level Detection

• T1 - T5 BC 548 or 2N2222
• R1-R5 2.2K 1/4 W
• R6-R10 22K 1/4 W
• D1 - D5 LED’s

Use a transformer 6V 500 mA for power supply. Do not use a rectifier! we need pure AC. Use good quality insulated Aluminum wire for probes. If Aluminum wires are not available try Steel or Tin. Copper is the worst. Try the circuit first on a bread board and if not working properly, make adjustments with the resistance values . This is often needed because conductivity of water changes slightly from place to place.

3 led Level Audio amplifier Indicator

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This circuit ican be used to show the power output level of any audio amplifier. The circuit is very simple and displays three power levels that can be set to any desired value. For a standard HiFi stereo power amplifier like the 25W MOSFET Audio Amplifier.

Skema Rangkaian 3 led Level Audio amplifier Indicator

Component List Of 3 led Level Audio amplifier Indicator

R1.................. 100K 1/4W Resistor
R2.................. 50K 1/2W Trimmer Cermet
R3.................. 330K 1/4W Resistor
R4.................. 1M2 1/4W Resistor
R5.................. 470K 1/4W Resistor
R6,R7............. 500K 1/2W Trimmers Cermet
R8.................. 1K5 1/4W Resistor
R9-R11............ 470R 1/4W Resistors
C1.................. 47pF 63V Ceramic Capacitor
C2.................. 100nF 63V Polyester Capacitor
C3.................. 47µF 25V Electrolytic Capacitor
C4.................. 1µF 25V Electrolytic Capacitor
D1.................. BZX79C5V1 5.1V 500mW Zener Diode
D2.................. 1N4148 75V 150mA Diode
D3-D5.............3mm. Yellow LEDs
IC1.................. LM339 Quad Voltage Comparator IC
SW1.................. SPST Slider Switch
B1.................. 9V

Other settings are possible IC1A is the input buffer, feeding 3 voltage comparators and LEDs drivers by means of a variable dc voltage obtained by R5 and C4 smoothing action. In order to achieve stability settings, the supply of IC1 and trimmers R6 & R7 is reduced and clamped to 5.1V by Zener diode D1.


About IC LM339

The LM139 series consists of four independent precision voltage comparators with an offset voltage specification as low as 2 mV max for all four comparators. These were designed specifically to operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage. These comparators also have a unique characteristic in that the input common-mode voltage range includes ground, even though operated from a single power supply voltage.

Application areas include limit comparators, simple analog to digital converters; pulse, squarewave and time delay generators; wide range VCO; MOS clock timers; multivibrators and high voltage digital logic gates. The LM139 series was designed to directly interface with TTL and CMOS. When operated from both plus and minus power supplies, they will directly interface with MOS logic- where the low power drain of the LM339 is a distinct advantage over standard comparators.

IC LM339 Applications

• High precision comparators
• Reduced VOS drift over temperature
• Eliminates need for dual supplies
• Allows sensing near GND
• Compatible with all forms of logic
• Power drain suitable for battery operation.

Sound Level (Decibel) Meter Circuit

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This is a decibel meter electronic circuit, For an audio engineer, this circuit seems to be very helpful, especially for checking of sound pressure levels from about 60 to 70 Decibel (dB). EACH light represents about a 3dB change in sound level so That Pls all three lights are on, the sound level is about 4 times Greater than the level needed to light one lamp. The sensitivity cans be adjusted with the 500K pot so That one lamp comes on with a reference sound level. The other two lamps will from then indicate about a 2X and 4X increase is in volume.

Circuit of Sound Level (Decibel) Meter

In operation, with no input, the DC voltage at pins 1,2 and 3 of the op-amp will be about 4 volts, and the voltage on the (+) inputs to the 3 comparators (pins 5,10,12) will be about a half volt less due to the 1N914 diode drop. The voltage on the (-) comparator inputs will be around 5.1 and 6.5 which is set by the 560 and 750 ohm resistors.

When an audio signal is present, the 10uF capacitor connected to the diode will charge toward the peak audio level at the op-amp output at pin 1. As the volume increases, the DC voltage on the capacitor and also (+) comparator inputs will increase and the lamp will turn on when the (+) input goes above the (-) input. As the volume decreases, the capacitor discharges through the parallel 100K resistor and the lamps go out. You can change the response time with a larger or smaller capacitor.

Source: www.bowdenshobbycircuits.info

Audio Peak Level Indicator By Op-Amp

simple circuit PEAK indicator of foliage of the musical signal. This circuit was designed to provide a valuable test equipment tool for sound reinforcement systems like sound amplifiers and the like. The circuit is formed by an input buffer and ac to dc voltage converter (IC1A) feeding a window comparator (IC2A, IC2B, IC2C) which illuminates one of three LEDs at a time.

Skema Rangkaian Audio Peak Level Indicator By Op-Amp

No setup is required: if correct values are used for resistors R3 to R7, LED D1 will illuminate at 0dB input (0.775V RMS), LED D2 at +5dB input (1.378V RMS) and LED D3 at +10dB (2.451V RMS).

The circuit was optimized for low current consumption as it was intended for battery operation. To achieve this, the best arrangement has proven to be the one using two different op-amp types for IC1 and IC2. In fact the LM393 IC was not operating satisfactorily as dot-mode LED driver, whereas the LM324 was unable to charge C2 in the linear way, as expected. Therefore, the final circuit is some op-amp wasting, but the small added cost will be quickly compensated by battery savings.

List Component:

R1 : 300K D1,D2,D3 : LEDs
R2 : 1M2 IC1 : LM393
R3 : 510K IC2 : LM324
R4 : 220K IC3 : 78L05
R5 : 91K SW1 : SPST Toggle or Slider Switch
R6 : 160K B1: 9V PP3 Battery
R7 : 56K
R8,R9 : 100R
R10 : 220R
C1 : 100nF
C2 : 1µF/63V
C3 : 10µF/25V