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

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Pembanding Tegangan Menggunakan Op-Amp

Rangkaian Pembanding Tegangan

This following project serves to compare whenever the input voltage differs from two defined limits, V1 and V2. This circuit will provide an indication whenever the input voltage differs from two defined limits, V1 and V2. The supply voltage, Vcc must be higher than the highest input voltage by at least 2 volts. One application here is to monitor a 12V car battery. V1 could be set to 14V and V2 to 11V thus giving an indication of over charge or a weak battery.

Skema rangkaian pembanding tegangan

The CA3140 op-amps are used to advantage as they have very little output offset voltage and can switch down to near 0volts. If any other op-amp is used such as CA741 or LF351 then it will be necessary to have an offset null control. This is just a 10k preset pins contacted between 1 and 5, the wiper connected to the negative supply rail op-amps or 4 pins. With this circuit the op-amp either will light the LED if the input voltage goes out of limits, the two 1N4148 diodes forming an "AND"-gate at the output. The input voltage to be Monitored is fed via a series 10k resistors to inputs of both op-amps. If the input voltage is greater than the limit set by V1 then the CA3140 will swing its output to almost the full supply voltage and light the LED. Similarly, if the input voltage is less than the limit defined by V2 then this op-amp will swing towards Vcc and light the LED.

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Rangkaian Driver (Penggerak) PlayBack TV

Driver (Penggerak) PlayBack TV

This is an efficient flyback driver for modern cylindrical rectified television flybacks. Frequency range can be increased using multiposition switch for other values of C3 capacitor, for example 2 nF for 80KHz-200000KHz, but didn't found flybacks with so high resonant frequencies, in addition with higher values of c3 , eg 200nF, 2uF the frequency will drop making possible the use of ignition coils, and rectified power transformers @50Hz to charge high voltage electrolitic caps at 300-400V).

Skema rangkaian driver (penggerak) playback TV

The 555 is wired as an astable and the capacitor is charged only through the 4,7Kohm trimmer (notice the diode) and discharged only through the 2.2 Kohm trimmer, making the duty cycle full adjustable. The square wave is then feed in a totem pole made up of a 2N3904 and a 2N3906, which are cheap, and easy to find. The totem pole ensures the gate being charged and discharged very fast (approx 50nS). The IRF840 is a cheap reliable and powerful power mosfet, it has current capability of 8 A continuous and 32A pulse, 800V drain source voltage, protecting internal zener diode. There is a snubbing network to ensure that voltage spikes are kept low (unless the insulation of the transformer start to leak) protecting both transistors and 555 IC. 100 ohm is a compromise between decay time and voltage spike.

Note:
The flyback driven in this way can supply a significant current, aldough the heart fibrillation starts at 30mA I recommend caution to avoid painful arc-burns. The arc is a hot plasma, never operate the circuit in presence of flammable substances. Charging high voltage capacitors is a serious life threat, so if you arent unexperienced just draw arcs and no more This device when rectified generates static voltage that can be a little annoying

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Rangkaian Diferensiator Op-Amp

Diferensiator circuit functions to produce a voltage which is a function of the time differential input voltage. Diferensiator circuit is basically a pass-filter for condenser consisting of rows and row resistor. Because the condenser reactance increases if the frequency falls, this circuit eliminates the low frequency components of an input. If there is input level applied to diferensiator, voltage on the condenser is changed in an instant so that there is voltage on the resistor decreases exponentially in accordance with the formula
CR is a constant time, ie the product of the resistance capacity. In one time constant, voltage condenser membentangi approximately 63%. It takes nearly 5 time constants to empty the condenser.

Skema Rangkaian Diferensiator Op-Amp

The formula for determining voltage output for the diferensiator is as follows:

Applications for this, besides representing the derivative calculus function inside of an analog computer, include rate-of-change indicators for process instrumentation. One such rate-of-change signal application might be for monitoring (or controlling) the rate of temperature change in a furnace, where too high or too low of a temperature rise rate could be detrimental. The DC voltage produced by the diferensiator circuit could be used to drive a comparator, which would signal an alarm or activate a control if the rate of change exceeded a pre-set level.

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Rangkaian Integrator Op-Amp 741

Op-amp is versatile electronic circuits are designed and specially packaged, so that by adding external components at all, can already be used for various purposes. One of them is to make the integrator integrator circuit functions to produce an output voltage which is an integral function of time from the input voltage.

Rangkaianintegrator widely used in the "analog computer" as a tool for solve the integral equation. This circuit can be made by placing capacitors at the input and output reversed and no-reverse input earthed. Input signal given to the input reversed.

Skema Rangkaian Integrator Op-Amp 741

Integrator circuit testing procedures

• Arrange an op-amp integrators as shown in the image above. Supply Power dibua IC 741 can use two batteries or variable DC source.
• Set the input signal from the FG to generate signal box 1 Vp-p on frequency of 1 kHz.
• Use the oscilloscope to view the integrator output response
• Based on the circuit as shown above, you will verify that the output and input will follow the equation

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Rangkaian Comparator Tegangan

This is a Voltage Comparator circuit can be uses indicates the input voltage differs from two defined limits, V1 and V2.

One application here is to monitor a 12V car battery. V1 can be set to 14V and V2 to 11V thus giving an indication of more than the cost or weak batteries. Op-amp used here is the CA3140 MOSFET. They are used to advantage because they have less output offset voltage and can switch to 0volts close. If any other use op-amps like the LF351 or CA741 will need to have an offset null control. This is just a 10k preset reached between pins 1 and 5, the wiper connected to the negative supply op-amps or 4 pins. The following is a schematic drawing:

Rangkaian Comparator Tegangan Sederhana

With this circuit the op-amp will turn on the LED if the input voltage out of limits, the two 1N4148 diodes to form an “AND”-gate at the output. Input voltage to be monitored are fed through a series of 10k resistors on the input of both op-amps. If the input voltage is greater than the limit set by V1 it will CA3140 output swing to almost full supply voltage and LED lights. Similarly, if the input voltage is less than the limit set by V2 the op-amp will swing to the Vcc and the LED light.

IC CA3140 Description

The CA3140 is integrated circuit operational amplifiers that combine the advantages of high voltage PMOS transistors with high voltage bipolar transistors on a single monolithic chip.


Absolute Maximum Ratings

DC Supply Voltage (Between V+ and V- Terminals) . . . . . . . . . 36V
Differential Mode Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 8V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . (V+ +8V) To (V- -0.5V)
Input Terminal Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA
Output Short Circuit Duration∞ (Note 2) . . . . . . . . . . . . . . Indefinite
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC
Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC
Maximum Storage Temperature Range . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC

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Rangkaian Low pass Filter aktif

frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a high-cut filter, or treble cut filter when used in audio applications. A low-pass filter is the opposite of a high-pass filter, and a band-pass filter is a combination of a low-pass and a high-pass.

The concept of a low-pass filter exists in many different forms, including electronic circuits (like a hiss filter used in audio), digital algorithms for smoothing sets of data, acoustic barriers, blurring of images, and so on.

in the image below in the show Rangkaian Aktif low pass filter using op amp lm 741:

Skema rangkaian Low pass Filter aktif

In the operational amplifier circuit shown in the figure, the cutoff frequency (in hertz) is defined as:


or equivalently (in radians per second):


The gain in the passband is


and the stopband drops off at −6 dB per octave as it is a first-order filter.


Sometimes, a simple gain amplifier (as opposed to the very-high-gain operation amplifier) is turned into a low-pass filter by simply adding a feedback capacitor C. This feedback decreases the frequency response at high frequencies via the Miller effect, and helps to avoid oscillation in the amplifier. For example, an audio amplifier can be made into a low-pass filter with cutoff frequency 100 kHz to reduce gain at frequencies which would otherwise oscillate. Since the audio band (what we can hear) only goes up to 20 kHz or so, the frequencies of interest fall entirely in the passband, and the amplifier behaves the same way as far as audio is concerned.

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Rangkaian Konfigurasi Common Emitter dan Collector

Rangkain Konfigurasi Common Emitte

Transistor configuration that is most often found configuration Common Emitter (CE). Called the Common Emitter (CE) as the emitter on the side with the input and output.

Rangkain Konfigurasi Common Emitte

In this configuration, the relationship between the flow base, emitter and collector is fixed.

• IE = IB + IC

In the configuration Emitter Common characteristics of the output is kurva between the output currents to the IC output voltage VCE at a flow rate range of input IB. Characteristics kurva input is the input current IB to the input voltage VBE on the value of output voltage VCE.

Kurva Karakteritik Output & Kurva Karakteritik Input

Note that the output characteristics kurva, IB current does not horizontally as well as IE in common base configuration, the indicates that the collector-voltage emiter (VCE) affect the amount of current collector. Active area for common emitter configuration is a region in the top right where IB kurva flow near straight line (linear). In the picture, this region is located on the right-VCE sat and above kurva IB = 0. Area in the left-VCE sat is the saturation. Flow conditions on the collector IB = 0 is expressed as follows:

In DC mode, IB and IC level associated with a defined amount of beta:


In the specification / data sheet, βdc written hFE. To ac mode:

Ac strengthening also known as hfe. (note the difference with hFE) Βdc and βac generally worth the same as written and β only. The relationship between β and α are as follows:

With IC = βIB can also be derived:


Rangkaian Konfigurasi Common Collector

Common Collector configuration is generally used as a series of adjustments because Impedance Impedance has a high input and low output Impedance, contrary to the two previous configurations (CB and CE).
Characteristics of CC input configuration is the same as the characteristics of the CE configuration. Output characteristics is a plot of IE with the VEC for the values of IB, kurva form with the same characteristics as the output CE.

Rangkaian Konfigurasi Common Collector

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Rangkaian Common Base Configuration

Transistors operating

Transistor operating with a bias in both Junction (base-emitter and base-collector). Total current from the emitter terminal is the same as the flow in the collector terminal on the terminal plus cash basis.

• IE = IB + IC

ICO value is very small and generally can be ignored Base-emitter voltage (VBE) can be considered as a variable in determining the controller transistor operation

Collector current IC of the proportional relationship with the current IB IC = β IB. The greater the flow of IB also IC flow, seems to have the flow. Data specification transistor (from factory) in the set maximum value that should not be dilampaui in operation. This specification provides limits of transistor operation in the series.

Collector current IC consists of two components, originating from the majority carrier and minority carrier. Flow of minority carriers is called the ICO

• IC = IC majority + ICO minority

ICO value is very small and generally can be ignored Base-emitter voltage (VBE) can be considered as a variable in determining the controller transistor operation

Collector current IC of the proportional relationship with the current IB IC = β IB. The greater the current of IB also current IC. Data specification transistor (from factory) in the set maximum value that should not be skipped in the operation. This specification provides limits of transistor operation in the series.

Common Base Configuration

Naming base comes from the common condition where the base used in the joint input and output.

Direction of flow indicated is the direction of conventional flow. Characteristics such as the strengthening of this characteristic is described in kurva input and output characteristics kurva. Characteristics between the input current IE to the input voltage VBE for some value of output voltage VCB. Characteristics of the output current output voltage of IC output for some values VCB IE.

Kurva Karakteristik input & output Common Base Configuration

Characteristics of output has three working areas, namely active, the cut-off and saturation. Active region is a region where the linear case. Specifically stated: "In the active region, Junction base-collector reverse bias while at the Junction in the base-emitter forward bias. "

At the bottom of the active region, where the emitter current IE = 0, collector currents flow only from behind the ICO the saturation value is very small (in the micro-ampere), so it can be ignored.

the cut-off is defined as the area where the current IC = 0 A. or indicate : "Regional cut-off occurs when Junction base-collector and base-emitter Junction in reverse bias."

Saturation region is a region where the value of a negative voltage VCB. or indicate: "Region is a region where saturation Junction base-collector and base-emitter Junction in forward bias."

Characteristics of the input seen that for fixed value of VCB, when the base-emitter voltage (VBE) has increased, flow increased as well as the emitter on the diode. Raising the voltage VCB has a very small impact so that it can be ignored. Model ekivalen input from kurva characteristics are as following picture:

In further analysis, when the transistor is in a condition "on", the assumed base-emitter voltage:

Alpha

In DC mode, flow-level IC and IE comes from the majority carriers have a relationship:

Because α is determined from the majority carrier, then

ICBO generally very small so it can be ignored. For ac current, α is defined:

αac formally known as the common base, chort circuit, amplification factor. Value αac and αdc quite close, so often expressed as α only.

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Rangkaian Penguat Tak Membalik/Differensial Op Amp 741

Penguat Operasional (Operasional Amplifier)

Brace OPERATIONAL (OP-AMP) is a series of integration (IC) that is capable of linier provide the very large and can be operated at intervals voltage which is quite big. Op-amp to be able to give up at the 100,000 for an op-amp in a series of open-Hubung until only of 1 (one) time when the cohort is used as a series of voltage (voltage FOLLOWER).

Penguat Tak Membalik

The following circuit schemes is an Op Amp is applied in a non-inverting amplifier mode, the output voltage (Vo) has the same phase with the input voltage (Vi). From the way the arrangement can be seen that the input signal is connected to input non-inverting Op-Amp, so the output signal has the same phase with the input signal.

Skema Rangkain Penguat Tak Membalik

As shown in the picture sequence above, the output voltage has the same phase with voltage inputs. The amount of strengthening the non-inverting circuit is determined from a comparison of the value of R1 and R2. Resistors R1 and R2 form a resistive divider network to provide the feedback voltage (VA) are needed to reverse the input.

Show that the gain of the amplifier is:
Output voltage can be calculated using the following formula:

Penguat Differensial

Penguat Differensial is a brace which the output voltage Vo is or is the result of the difference between the two voltage inputs on the terminal non-inverting and inverting it. General formula that applies to brace differensial is as follows:

Rangkaian differensial brace shown in Figure below.

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PENGUAT OP-AMP (LM 741)

Penguat membalik

Penguat Op-Amp membalik akan menguatkan tegangan pada masukan serta membalik hasil penguatan tersebut, jadi keluaran dari rangkaian ini akan selalu memiliki polaritas yang berlawananan dengan sinyal masukannya.

Penguatan tegangan pada rangkaian ini di tentukan menurut

Tegangan keluaran diperoleh dengan jalan mengalikan tegangan masukan yang diketahui dengan factor penguatan, atau

Tanda minus diabaikan dalam perhitungan karna hanya menunjukkan bahwa keluaran berlawanan fasa terhadap masukannya.

Penguat tak membalik

Dalam konfigurasi ini umpan balik yang digunakan untuk mengatur penguatan tetap di berikan pada masukan membalik, tapi Vin di berikan pada masukan tak membalik sehingga tegangan keluaran akan selalu sefasa dengan tegangan masukannya.

Untuk mendapatkan penguatan tegangan dapat dicari dengan persamaan berikut

Untuk memperoleh tegangan keluaran dapat dicari dengan mengalikan tegangan masukan yang diketahui dengan factor penguatan, atau

Penguat penjumlah tegangan

Dengan menggunakan rangkaian penguat membalik dasar dan menambahkan resistor pada masukan lainnya, kita dapat membuat penguat penjumlah membalik. Tegangan keluaran akan dibalik dan nilainya sama dengan penjumlahan aljabar dari masing-masing perkalian tegangan masukan dengan hasil bagi resistor masukan dengan resistor umpan balik yang bersesuaian, atau dapat dinyatakan sebagai berikut

Suku R_F/R_N (V_N) dalam rumus di atas menyatakan bahwa dalam rangkaian tersebut mungkin terdapat lebih dari dua masukan. Bila semua resistor luar sama nilainya (R_f = R₁ = R₂ = … = R_N), keluaran dapat dengan mudah dapat di hitung sebagai penjumlahan aljabar dari masing-masing tegangan masukan, atau

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