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Audio Filters Circuits
Audio Filters Circuits
A circuit diagram of the filter by the transistor
Described in this article is a band-pass filter is a circuit diagram of transistors, as shown below.
Simple design with a constant K-type high-frequency low-pass LC filter
Due to the amplifier frequency characteristics and impact of parasitic capacitance, to make hundreds of kilohertz to the active filter is very difficult.. On the other hand, si
The Q value of the variable notch filter
Double r circuit consists of three resistors, three capacitors, substantially symmetrical double insanity single passive attenuation characteristics of the filter element 0 0.2
Electronic filter The effect of the capacitor c5 is filtered. Cs fact constitute a composite pipe with an electronic filter, as shown in FIG. Thus the advantage law by using sm
Audio high-pass filter
Figure 1-102 high-pass filter in FIG. (A), and if we take C1 C2, R1 1/2, then the crossover, H 1/2 root of 2 R1C1. For Figure (b), if take C1 C2, R1 1/4R2, its crossover fH 1/2
Voltage Controlled Filter SSM2044P
At this circuit the SSM2044 IC is used, a 4 pole voltage controlled filter designed for electronic music applications. On-chip voltage control of resonance allows direct and easy interfacing with programmers and controllers. The IC features extended control range, low noise, and high control rejection. The filter can also be used as a low...
Wideband two-pole high-pass filter
The circuit provides a 10MHz cutoff frequency. Resistor R3 ensures that the input capacitance of the amplifier does not interact with the filter response at the frequency of interest.
Active band-reject filter
A filter with a band-reject characteristic is frequently referred to as a notch filter. A typical circuit using a Âµ 741 is the unity-gain configuration for this type of active filter shown. The filter response curve shown is a second-order band-reject filter with a notch frequency of 3 kHz. The resulting Q of this filter is about 23, with a...
The input signal is applied through R3 to the inverting input of the summing amplifier and the output is taken from the first integrator. The summing amplifier will maintain equal voltage at the inverting and non-inverting inputs. Defining 1/R1C1 as 1 and 1/R2C2 as u>2> th^ is now a convenient form to look at the center-frequency 0 and filter Q.
Audio notch filter 2
With the circuit shown here the response at one octave off tune is within 10% of the far out response: notch sharpness may be increased or reduced by reducing or increasing.respectively the 68 ohm resistor. Linearity tracking of R8 and R9 has no effect on notch depth.
Razor-sharp CW filter
The circuit consists of four stages of active bandpass filtering provided by two type-Âµ integrated-circuit dual op amps and includes a simple threshold detector (diodes Dl and D2) between stages 2 and 3 to reduce low-level background noise. Each of the four filter stages acts as a narrow bandpass filter with an audio bandpass centered at 750...
Bandpass and notch filter
The Quad op amp MC4301 is used to configure a filter that will notch out a given frequency and produce that notched-out frequency at the BP terminal, useful in communications or measurement setups.
Precise audio clipper
A differential amplifier makes an excellent audio clipper and can provide precise, symmetrical clipping. The circuit shown commences clipping at an input of 100 mV. The output commences clipping at Â±3 V. Matching Q7 and Q2 is necessary for good symmetrical clipping.
4.5Mhz notch filter
Component value sensitivityis extremely critical, as are temperature coefficients and matching of the components. Best performance is attained when perfectly matched components are used and when the gain of the amplifier is unity
High q notch filter
A shows a twin-T network connected to an LM102 to form a high Q, 60 Hz notch filter. The junction of R3 and C3, which is normally connected to ground, is bootstrapped to the output of the follower
This narrowband filter using the 741 operational amplifier can provide up to 60 dB of rejection. With resistors equal to 100 K and capacitors equal to 320 pF, the circuit will reject 50 Hz. Frequencies within the range 1 Hz to 10 kHz may be rejected by selecting components in accordance with the formula
This nonlinear, passive filter circuit rejects ripple (or unwanted but fairly steady-voltage) without appreciably affecting the rise time of a signal. The circuit works best when the signal level is considerably lower than the unwanted ripple, provided the ripple level is fairly constant
The first stage is a simple buffer used to isolate the signal source from the attenuator stages to follow. Each of the subsequent stages is preceded by a voltage divider formed by two resistors and CMOS switch. Provided that the CMOS switch for each stage is closed, the drive signal will be attenuated according to the basic voltage divider...
This circuit performs the function of dividing the input signal by a selected constant (1, 2, 4, 8, etc.). While T, Z, or L sections could be used in the input attenuator, this is not necessary since the amplifier loading is negligible and a constant input impedance is maintained. The circuit is thus much simpler and more accurate than the...
Automatic gain control is a very useful feature in a number of audio amplifier circuits: tape recorders, telephone speaker phones, communication systems and PA systems. This circuit consists of a HA-5144 quad op amp and a FET transistor used as a voltage-controlled resistor to implement an AGC circuit with squelch control. The squelch...
This is a second-order, low-pass filter with programmable cutoff frequency. This circuit should be driven from a low-source impedance since there are paths from the output to the input through the unselected networks. Virtually any filter function which can be constructed with a conventional op amp can be made programmable with the HA-2400.
This universal filter offers low-pass, high-pass, bandpass, band elimination, and all-pass functions. The Biquad consists of two successive integration stages followed by an inverting stage. The entire group has a feedback loop from the front to the back consisting of Rl which is chiefly responsible for controlling the center frequency, W...
The control voltage Vc easily sets the cutoff frequency w0 of this state-variable filter to any desired value, from about 1.7 MHz up to 5 MHz, with a BB 204 varicap and R = 100 KO. Vc can range from 0 to 28 V. This range changes the capacitance of the varicap from about 4 to 12 pF. The circuit consists of input summing circuit A1 and two...
This circuit filters noise, such as glitches and contact bounce, from digital signals. You can easily adjust the circuit for a wide range of noise frequencies. The circuit"s output changes state only if the input differs from the output long enough for the counter to count eight cycles. If the input changes before the counter reaches its...
A generalized circuit diagram of the two-pole state-variable active filter is shown. The state-variable filter can be inverting or noninverting and can simultaneously provide three outputs: low-pass, bandpass, and high-pass. A notch filter can be realized by adding one summing op amp. In the state-variable filter circuit, one amplifier...
This circuit is fed from the earphone jack of your receiver and goes to limiter control R6 and is then amplified by Ql: a common-emitter stage that has a voltage gain of only about 10, because of the negative feedback introduced by R3. The output of Ql is fed to a simple clipping circuit, consisting of diodes D1 through D4. The diodes,...
HA-5190 is rated for Â±5 V output swing, and saturates at Â±7 V. As with most op amps, recovery from output saturation is slow compared to the amplifier"s normal response time. Some form of limiting, either of the input signal or in the feedback path, is desirable if saturation might occur.
The circuit allows you to eliminate the vocal portion of an audio signal, while leaving the instru mental portion. The circuit mixes two channels that must be 180Â° out of phase, so the signals that form the center-stereo image is canceled out. Those signals usually appear in phase. Resistor R3 biases the noninverting input of Ul from a...
This filter is used to reject or block a frequency or band of frequencies. These filters are often designed into audio and instrumentation systems to eliminate a single frequency, such as 60Hz. Commercial grade components with 5%-10% tolerance produce a null depth of at least 30 to 40 dB. When a twinT network is combined with a TL081 op amp...
This circuit shows a twin-T network connected to an LMl02 to fonn a high-Q, 60-Hz notch filter. The junction of R3 and C3 which is normally connected to ground, is bootstrapped to the output of the follower. Because the output of the follower is a very low impedance, neither the depth nor the frequency of the notch change;
Otherwise properly mixed sounds often suffer from a predominant solo voice (which might, of course, be the intention). If
Voice Scrambler/Disguiser Circuit
This circuit uses two balanced modulators to produce a DSB signal and then reinsert the carrier, except t
Audio Amplifier Circuits
Audio Oscillator Circuits
Audio Mixer Circuits
Audio Equalizer Circuits
Audio Tone Balance Circuits
Beeper Buzzer Circuits
Vacuum-Tube Valves Circuits
Musical & Effects Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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