Guitar And Bass Sustain Circuit

If you are guitar player or want to have wonderful sound of a guitar, where the note just hangs there seemingly forever, you need a sustain booster for your guitar audio outputs. Sustain can be obtained by turning the amp up full, but the rest of the band will just kill you - they need to be able to hear themselves too! This little project is best used in the effects loop of a guitar amp (if it has one - not all do).  It can be used direct from the guitar, but the effect is not as good, since it is designed for relatively high levels (around 1 Volt). Here is a design for guitar and bass sustain schematic diagram. This is the figure of the circuit.

Greatly Expanded Scale Circuit Using LM3914

This is the circuit for bar mode using LM3914 IC for great expanded scale. This circuit is only consists of some resistors circuit. This is the figure of the circuit.


Placing the LM3914 internal resistor divider in parallel with a section (230Ω) of a stable, low resistance divider greatly reduces voltage changes due to IC resistor value changes with temperature. Voltage V1 should be trimmed to 1.1V first by use of R2. Then the voltage V2 across the IC divider string can be adjusted to 200mV, using R5 without affecting V1. LED current will be approximately 10mA. [Schematic source: National Semiconductor, Inc].

High Voltage AC Calibrator Circuit Using Op Amp

This a application circuit for calibration. This circuit is called high voltage AC calibrator circuit. In another dimension in sine wave oscillator design is stable control of amplitude. This is the figure of the circuit.


In this circuit, not only is the amplitude stabilized by servo control but voltage gain is included within the servo loop. A transformer is used to provide voltage gain within a tightly controlled servo loop. A voltage gain of 100 is achieved by driving the secondary of the transformer and taking the output from the primary. A current sensitive negative absolute value amplifier composed of two amplifiers of an LF347 quad generates a negative rectified feedback signal. This is compared to the LM329 DC reference at the third LF347 which amplifies the difference at a gain of 100. The 10 μF feedback capacitor is used to set the frequency response of the loop.

The output of this amplifier controls the amplitude of the LM3900 oscillator thereby closing the loop. As shown the circuit oscillates at 1 kHz with under 0.1% distortion for a 100 Vrms (285 Vp-p) output. If the summing resistors from the LM329 are replaced with a potentiometer the loop is stable for output settings ranging from 3 Vrms to 190 Vrms (542 Vp-p!) with no change in frequency. If the DAC1280 D/A converter shown in dashed lines replace the LM329 reference, the AC output voltage can be controlled by the digital code input with 3 digit calibrated accuracy. [Schematic diagram source: National Semiconductor, Inc]

Audio Graphic Equalizer Circuit Using Op Amp

This is a design circuit for audio graphic equalizers, that are very common as commercial products but circuits for them are very rarely published. This circuit is a simple design circuit. The circuit is need an op-amp for amplifying the input signal. This is the figure of the circuit.


Only one gyrator stage is shown: all 7 gyrators are the same circuit, only the capacitors change, as shown in the chart. I have shown three of the seven faders to show where they go. A gyrator is a circuit using active devices and transistors to simulate an inductor. In this case the gyrator is the transistor acting with R1, R3 and C2. It could just as easily be a unity gain op-amp. The circuit includes three formulae: one which gives f, the the centre frequency of the band. The second shows how the Q is related to the capacitor ratio. The third shows the impedance presented by the circuit. Note that this includes 3 terms, the first purely resistive, the second is the capacitive contribution from C1 and the third is an inductive term from the gyrator.

Audio Graphic Equalizer Circuit Using Op Amp

This is a design circuit for audio graphic equalizers, that are very common as commercial products but circuits for them are very rarely published. This circuit is a simple design circuit. The circuit is need an op-amp for amplifying the input signal. This is the figure of the circuit.


Only one gyrator stage is shown: all 7 gyrators are the same circuit, only the capacitors change, as shown in the chart. I have shown three of the seven faders to show where they go. A gyrator is a circuit using active devices and transistors to simulate an inductor. In this case the gyrator is the transistor acting with R1, R3 and C2. It could just as easily be a unity gain op-amp. The circuit includes three formulae: one which gives f, the the centre frequency of the band. The second shows how the Q is related to the capacitor ratio. The third shows the impedance presented by the circuit. Note that this includes 3 terms, the first purely resistive, the second is the capacitive contribution from C1 and the third is an inductive term from the gyrator.

High Impedance DC Voltmeter Circuit Using Op Amp

This is a design for a high impedance DC voltmeter. This circuit is design with built by uA741 IC. This IC is a op-amp non-inverting DC amplifier. The IC have negative feedback that is through a DC meter requiring 1mA for full scale deflection. This is the figure of the circuit.


The principle work of this circuit is since R6 is 100 Ohms, the meter will show full scale reading when the DC input voltage to pin3 is equal to the voltage drop across R6, viz 0.1 volts. Choice of R1 and R2 for getting different voltage ranges are shown in the table. The diodes D1 and D2 protect the IC from accidental excessive input voltages and diodes D3 and D4 protect the meter from overloads. The circuit can be powered from a +9V/-9V dual power supply.

The meter M1 can be a 1mA FSD DC ammeter. The values of R1 & R2 for different voltage ranges can be obtained from the table is given below.

-5 Volt Generating Circuit Using 555 Timer IC

The generator circuit using 555 IC is a simple model to produce negative voltage. This voltage is resulted by 9 Volt batteries. The simple figure is shown in below. A 555 timer can be used to generate a square wave to produce a negative voltage relative to the negative battery terminal.


Operation of this circuit is starting when the timer output is at pin 3 goes positive, the series 22 uF capacitor charges through the diode (D1) to about 8 volts. When the output switches to ground, the 22 uF cap discharges through the second diode (D2) and charges the 100 uF capacitor to a negative voltage. The negative voltage can rise over several cycles to about -7 volts but is limited by the 5.1 volt zener diode which serves as a regulator. Circuit draws about 6 milliamps from the battery without the zener diode connected and about 18 milliamps connected. Output current available for the load is about 12 milliamps. An additional 5.1 volt zener and 330 ohm resistor could be used to regulate the +9 down to +5 at 12 mA if a symmetrical +/- 5 volt supply is needed. The battery drain would then be around 30 mA.

AIC1563 for 5V/1A step-down type DC to DC Voltage Converter

This the control of the circuit is used to detect the output voltage level and generates a driving signal to turn on or turn off on the power switch (SW). The power switch can be controlled by using different methods, such as pulse width modulation (PWM), pulse frequency modulation (PFM), or pulse skipping modulation (PSM), depends on the applications. As for the output voltage stability, it is maintained by controlling the duty cycle without losing energy. This may be illustrated by examining the energy stored in the inductor.

The Figure is in below;

The input electric energy is delivered to the load and partially stored in an inductor during the power switch turned on. The stored energy will be also transferred to the load through a free-wheel diode during the power switch turned off. PWM control method is used to illustrate the relationship between input and output voltage. It can also be applied to both PFM and PSM. To prevent the inductor from saturation, the inductor must release the same amount of energy as is stored under the stable condition. If not so, the inductor will enter a saturation region and lose its capability of storing energy due to unbalanced energy. The working voltage of AIC1563 is between 3V and 30V. It is recommended to operate it between 50KHz and 100KHz to obtain an optimum performance, although its operating frequency is ranging from 10 Hz to 100 kHz. AIC1563 is controlled by pulse skipping modulation (PSM). The main voltage source required for the electronic system products such as video CD, DVD, modem, and scanner is either 5 V or 12 V, with a maximum current of 1 A. We take this as an example to design a 5V/1A constant voltage DC/DC converter.

12 – 120 V Inverter

Ever needed a low power 120volt AC power source for your car, van or truck? Well this circuit should do the trick for you. This is the design for the problem. The circuit will supply 15 watts of AC power to a device. The circuit should power lamps, shavers, small stereos and small appliances. If you draw to much power the circuit will shut down all by itself.

The output of this circuit is a square wave so there may be some noticeable hum on audio units plugged into it. To reduce some of the hum increase the value of the output capacitor which is at .47uf now. That transistor in the circuit are high power PNP transistors. Radio Shack part number 276-2025 are good ones to use or TIP32. The transformer is a 24 volt 2 amp center tapped secondary Radio Shack part number 273-1512 or equivalent.

Voltage Feedback Op Amps

The voltage feedback (VF) operational amplifier (op amp) is the most common type of op amp. The less well known current feedback (CF) op amp has been commercially available for about 20 years, but many designers are still uncertain about how to use them. Terminology is a confusing factor for many people. The CF op amp is a trans impedance op amp and so has a different vocabulary associated with it. This report attempts to show that there are more similarities than differences between CF and VF op amps when considering basic circuit operation.

The ideal VF op amp model is a powerful tool that aids in understanding basic VF op amp operation. There is also an ideal model for the CF op amp. Figure (a) shows the VF ideal model and Figure (b) shows the CF ideal model.

Figure:

In a VF op amp,

Vo = a x Ve (1)

Where Ve = Vp – Vn is called the error voltage and a is the open loop voltage gain of the amplifier.

In a CF op amp,

Vo = ie x Zt (2)

Where ie is called the error current and Zt is the open loop trans impedance gain of the amplifier. An amplifier where the output is a voltage that depends on the input current is called a trans impedance amplifier because the transfer function equates to an impedance i.e.,

Vo/ie = Zt

Source: James Karki / Texas Instruments

Low Frequency Sine wave Generators Schematic

The two circuits below illustrate generating low frequency sine waves by shifting the phase of the signal through an RC network so that oscillation occurs where the total phase shift is 360 degrees. The transistor circuit on the right produces a reasonable sine wave at the collector of the 3904 which is buffered by the JFET to yield a low impedance output. The circuit gain is critical for low distortion and you may need to adjust the 500 ohm resistor to achieve a stable waveform with minimum distortion. The transistor circuit is not recommended for practical applications due to the critical adjustments needed.

The op-amp based phase shift oscillator is much more stable than the single transistor version since the gain can be set higher than needed to sustain oscillation and the output is taken from the RC network which filters out most of the harmonic distortion. The sine wave output from the RC network is buffered and the amplitude restored by the second (top) op-amp which has gain of around 28dB.

Frequency is around 600 Hz for RC values shown (7.5K and 0.1uF) and can be reduced by proportionally increasing the network resistors (7.5K). The 7.5K value at pin 2 of the op-amp controls the oscillator circuit gain and is selected so that the output at pin 1 is slightly clipped at the positive and negative peaks. The sine wave output at pin 7 is about 5 volts p-p using a 12 volt supply and appears very clean on a scope since the RC network filters out most all distortion occurring at pin 1.

Differentiator Op-Amp Circuit

Differentiator circuit is application circuit from playable mathematics formula (influenced) from capacitor activity. The circuit like at picture under this with simple circuit from differentiator. To get formula differentiator, the sequence is as following: Ic = Ib + If and during value Ib = 0 hence Ic = If difference from inverting input and non-inverting input (v1 and v2) be the null and voltage amplification is very big.

At the application of differentiator circuit this op-amp there are a few changes that is addition of prisoner and capacitor which the function input signal filter to. Like seen at picture following is differentiator circuit intended. If, when input signal exceeds frequency fa hence result of output would equal to result of input, alias function of the differentiator circuit shall no longer again but as ordinary. While to drawing 226 usually applied for application integrated circuit with other application. Condition calculation value R1, C1, RF, CF is as according to condition that is:

fa

so input frequency is overcome beforehand to R1, C1 , RF, then pass to R1, C1, CF if, when the frequency exceeding fa.

Timer Batterays Supply

One needs that is often emerges at equipments energy by battery was that battery can be killed after one certain time periods. Though circuit timer a lot, but no matter simple to be able to decide power supply allowance after used for several hour/clock. circuit depicted here can did this task by using current only some nanoampere.

View at circuit diagram shows that not many component applied. Switches S1 is nipple " ON", if it is depressed will ration bases rudder current at transistor Darlington T1 which then menghantarkann will to ration equipments is being used. Transistor T2 now will pass also, and acts as breach-block S1 in business is maintaining bases current to T1. Condenser C1 will start filling R4. if strain at R4 shoot until 1, 2V, hence T2 will break. In turn, this thing will kill T1 and hence allowance will be desisted also. The only flowing current is blowby current passing both transistors, but this biggest current only some nanoampere only. for all need, battery allowance will be stopped.

For they hesitating of mentoba " tries and sees" possibly will require more time, but will work good. If required, both replaceable Darlington with separate transistor.