Simple Low-pass filter Circuit Diagram

This Simple Low-pass filter Circuit Diagram 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 circuit has characteristics similar to two peak-detecting sample-and-hold circuits in tandem with a voltage average.

 Simple Low-pass filter Circuit Diagram


Simple Low-pass filter Circuit Diagram

Universal Compander Circuit diagram

Signet type NE575 compander IC is intended primarily for use with battery power supplies of 3 to 7 V (max. 8 V). Itdraws a current of 3.5 mA at 3 V and 5 mA at 7 V. The compander process (compression at the input, expansion at the output) significantly improves the signal-to-noise ratio in a communications link. 

 Universal Compander Circuit diagram

Universal Compander Circuit diagram


The IC contains two almost identical circuits, of which one (pins 1 to 9) is arranged as an expander. The other (pins 11 to 19) can be used as expander, compressor or automatic load control (ALC), depending on the externally connected circuit. For the compressor function, the inverting output of the internal summing amplifier is brought out to pin 12. 

This is not the case in the expander section, where a reference voltage is available at pin 8. This pin is interlinked to pins 1 and 19 to enable the setting of the dc operating point of the op amps. The op amp in the expander section, pins 1 through 3, serves as output buffer in the compressor section, pins 17 through 19 as the input buffer. The IC has a relatively high output sensitivity and is evidently intended for processing small signals (microphone output level). 

A signal of 100 mV, for instance, is amplified by 1 only. The present circuit caters to larger input signals (line level); its maximum input level is 1.5 Vrms. With a 1-V input into R13, a potential of about 500 mV exists between compressor output R7 and expander input R5. The compression characteristic is shown in Fig. 19-2 (b). The signal range is reduced by about one half at the output, which is doubled in the expander. Thus, the range after compression and expansion is the same again, but that is not necessarily the case with the input and output level. The compander can be arranged to provide a constant attenuation or amplification. With the circuit values as shown in the diagram, the input and output levels are the same. 

The prototype had an overall gain of 0.5 dB when the expander input was connected directly to the compressor output. To allow acceptance of high input levels, R13, R14, and the compressor input resistance form a 10:1 attenuator. At the expander input, R5 and the expander input impedance of about 3 kfl form a potential divider. If the compander is to be used with smaller signals, the attenuation can be reduced as appropriate. If the input level lies below 100 mV, R5, R13 and R14 can be omitted. The compander covers the frequency range of 20 Hz to 20 kHz, the overall distortion is less than 1%, and the signal-to-noise ratio is about 80 dB.

Vocal Eliminator Circuit Diagram

Otherwise properly mixed sounds often suffer from a predominant solo voice (which might, of course, be the intention). Ifsuch a voice needs to be suppressed, the present circuit will do the job admirably. The circuit is based on the fact that solo voices are invariably situated `at the center` of the stereo recordings that are to be mixed. Thus, voice levels in the left- and right-hand channels are about equal. Arithmetically, therefore, left minus right equals zero; that is, a mono signal without voice. 

 Vocal Eliminator Circuit Diagram
Vocal Eliminator Circuit Diagram

 There is, however, a problem: the sound levels of bass instruments, more particularly the double basses, are also just about the same in the two channels. On the one hand low-frequency sounds are virtu--ally nondirectional and on the other hand, the recording engineers purposely use these frequencies to give a balance between the two channels. However, the bass instruments can be recovered by adding those appearing in the left + right signal to the left-right signal. 

The whole procedure is easily followed in the circuit diagram. The incoming stereo signal is buffered by A1 and A2. The buffered signal is then fed to differential amplifier A3 and subsequently to summing amplifier A5. The latter is followed by a low-pass filter formed by A6. You can choose between a first-order and a second-order filter by respectively omitting or fitting C2. Listen to what sounds best. The low-frequency signal and the difference signal are applied to summing amplifier A4. 

The balance between the two is set by PI and P2 to individual taste. You have noticed that the circuit does not contain input or output capacitors. you wish, output capacitors can be added without detriment. However, adding input capacitors is not advisable, because the consequent phase shift would adversely affect the circuit operation.

Simple Notch filter uses an Operational Amplifier

This notch filter is useful for tunable band-reject applications in the audio range.The values shown will give a tuning range of about 300-1500 Hz.

 Notch filter uses an Operational Amplifier Circuit Diagram

 Notch filter uses an Operational Amplifier Circuit Diagram

Simple Noise limiter Circuit Diagram

This Noise limiter Circuit Diagram improves signal-to-noise ratio. It is connected between the detector output and the audio input (if high impedance) or at some relatively high-impedance section between two audio stages—preferably the low level stages.D1 and D2 can be any diode having relatively low forward resistance and very high back resistance. The circuit is excellent for receivers having bandwidths down to 2 or 3 kHz. Increase the value of Cl for receivers having narrower bandwidths . 

Noise limiter Circuit Diagram


Noise limiter Circuit Diagram

Build a Derived Center-Channel Stereo System Circuit Digram

A simple method of deriving a center or third channel without the use of an extra transformer or amplifier, (a) 4- speakers are connected to 8- amplifier taps. 8 and 16- speakers connect to 16- taps, (b) By blending the inputs it is possible to cancel out undesired crosstalk. 

Derived Center-Channel Stereo System Circuit Digram
 
Derived Center-Channel Stereo System Circuit Digram

Battery-powered-high-voltage-generator Circuit Diagram

Battery-powered-high-voltage-generator Circuit Diagram . Output voltage great enough to jump a l-inch gap can be obtained from a 12-V power source. A 555 timer IC is connected as an astable multivibrator that produces a narrow negative pulse at pin 3. The pulse turns Ql on for the duration of the time period. The collector of Ql is direct-coupled to tbe base of tbe power transistor Q2, turning it on during the same time period.  

The emitter of Q2 is direct -coupled through current limiting resistor R5 to the base of the power transistor. Q3 switches on, producing a minimum resistance between the collector and emitter. The high-current pulse going through tbe primary of high-voltage transformer Tl generates a very high pulse voltage at its secondary output terminal (labeled X). The pulse frequency is determined by tbe values of Rl, R2, and C2. The values given in the parts list were chosen to give the best possible performance when an auto-ignition coil is used for Tl.  

Battery-powered-high-voltage-generator Circuit Diagram

Battery-powered-high-voltage-generator Circuit Diagram

Power Mosfet Inverter Circuit Diagram

This Power Mosfet Inverter Circuit Diagram can deliver .high-voltage ac or de, with a rectifier and filter, up to several hundred volts. The secondary and primary of T1-a 12.6 to 440 V power transformer, respectively-are reversed; e.g., the primary becomes the secondary and the secondary becomes the primary. Transistors Q1 and Q2 can be any power FET. Be sure to heat sink Q1 and Q2. Capacitors C1 and C2 are used as spike suppressors. 

Power Mosfet Inverter Circuit Diagram


Power Mosfet Inverter Circuit Diagram

Battery charger with LM317 Circuit Diagram

Battery charger with LM317 Circuit Diagram. An LM317 voltage regulator is configured as a constant-current source. It is used to supply the 50 mA charging current to S01-S06, an array of AA-cell battery holders. Each of the battery holders is wired in series with an LED and its associated shunt resistor. When the battery holder contains a battery, the LED glows during charging. Each battery holder/LED combination is paralleled by a 5.1-volt Zener diode. If the battery holder is empty, the Zener conducts the current around the holder. 

A timing circuit prevents overcharging. When power is applied to the circuit, timing is initiated by IC2, a CD4541 oscillator/programmable timer. The output of IC2 is fed to Ql. When that output is high, the transistor is on, and the charging circuit is completed. When the output is low, the transistor is off, and the path to ground is interrupted. 

 Battery charger with LM317 Circuit Diagram


Battery charger with LM317 Circuit Diagram

Diode less Rectifier Circuit Diagram

Diode less Rectifier Circuit Diagram . It`s common knowledge that when working with single-supply op amps, implementing simple functions in a bipolar signal environment can be difficult. Sometimes additional op amps and other electronic components are required. Taking that into consideration, can any advantage be attained from this mode The answer lies in this simple circuit (A). Requiring no diodes, the circuit is a high-precision full-wave rectifier with a liigli-frequency limitation equalling that of the op amps themselves. Look at the circuit`s timing diagram (B) to see the principle of operation. The first amplifier rectifies negative input levels with an inverting gain of 2 and turns positive levels to zero .

The second amp, a noninverting summing amplifier, adds the inverted negative signal from the first amplifier to the original input signal. The net result is the traditional waveform produced by full-wave rectification. In spite of the limitation on the input signal amplitude (it must be less than VCCJZ), this circuit can be useful in a variety of setups.

 Diode less Rectifier Circuit Diagram


Diode less Rectifier Circuit Diagram

Simple Intelligent Battery-Charging Circuit Diagram

 Intelligent Battery-Charging Circuit Diagram . Intended for a Nicad application this charging circuit can be used with a wide range of batteries. A low-battery detector is intended. The trip voltage is set via the 500-kQ pot .
Select Rc for the battery you intend to use.

  Intelligent Battery-Charging Circuit Diagram


 Intelligent Battery-Charging Circuit Diagram

Purpose Power Supply Circuit Diagram

The Ppurpose Power Supply Circuit Diagram 6-66 can be used for supply output voltages from 1 to 35 V. The line transformer should be selected to give about1.4 times the desired output voltage from the positive side of filter capacitor C1 to ground. Potentiometer R2 sets the output voltage to the desired value by adjusting the reference input. Rsc is the current limit set resistor. Its value is calculated as: For example, if the maximum current output is to be 1 A, Rsc ~ 0.65/1.0 ~ 0.65 0. The 1-KO resistor, Rs, is a light-loaded resistor designed to improve the no-load stability of the supply.

 Purpose Power Supply Circuit Diagram


Ppurpose Power Supply Circuit Diagram

Build a Low voltage regulators Circuit Diagram

These Low voltage regulators Circuit Diagram short-circuit protected regulators give 6, 7, and 9 V from an automobile battery supply of 13 V nominal; however, they will function just as well if connected to a smoothed dc output from a transformer/rectifier circuit. Two types are shown for both positive and negative ground systems. The power transistors can be mounted on the heatsink without a mica insulating spacer thus allowing for greater cooling efficiency. Both circuits are protected against overload or short-circuits. The current cannot exceed 330 mA.

Under normal operating conditions the voltage across R2 does not rise above the 500 mV necessary to turn Q2 on and the circuit behaves as if there was only Q1 present. If excessive current is drawn, Q2 turns on and cuts off Ql, protecting the regulating transistor. The table gives the values of Rl for different zener voltages.

 Low voltage regulators Circuit Diagram

Low voltage regulators Circuit Diagram

Simple Ni-cad charger Circuit Diagram

Simple Ni-cad charger Circuit Diagram uses constant current LEDs to adjust charging current. It makes use of LEDs that pass a constant current of about 15 mA for an applied voltage range of 2-18 V. They can be paralleled to give any multiple of 15 mA and they light up when current is flowing.The circuit will charge a single cell at 15, 30 or 45 mA or cells in. series up to the rated supply voltage limit (about 14 V).

 Simple Ni-cad charger Circuit Diagram

Simple Ni-cad charger Circuit Diagram
 

Simple Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram

Simple Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram. For back-lit LCD displays, this supply will drive a lamp. LT1072 drives Ql and Q2, and a sine wave appears across CI. LI is a transformer that steps up this voltage to about 1400 V. Dl and D2 detect lamp current and form a feedback loop to the LT1072 to control lamp brightness. C1 = MUST BE A LOW LOSS CAPACITOR. METALIZED POLYCARB WIMA FPK 2 (GERMAN) RECOMMENDED. L1 = SUMIDA 6345-020 OR COILTRONIX CTX110092-1. PIN NUMBERS SHOWN FOR COILTRONIX UNIT. L2 = COILTRONIX CTX300-4 * = 1 % FILM RESISTOR. 

  Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram


 Cold-Cathode Fluorescent-Lamp Supply Circuit Diagram

Temperature Sensing Nicad Battery Charger Circuit Diagram

Temperature Sensing Nicad Battery Charger Circuit Diagram .Two simple circuits permit Nicad charging of a battery based on temperature differences between the battery pack and the ambient temperature. This method has the advantage of allowing fast charging because the circuit senses the temperature rise that occurs after charging is complete and the battery under charge is producing heat, not accumulating charge.

Temperature Sensing Nicad Battery Charger Circuit Diagram

Temperature Sensing Nicad Battery Charger Circuit Diagram

Regulator Loss Cutter Circuit Diagram

Regulator Loss Cutter Circuit Diagram . Large input-to-output voltage differentials, caused by wide input voltage variations, reduce a linear regulator`s efficiency and increase its power dissipation. A switching preregulator can reduce this power dissipation by minimizing the voltage drop across an adjustable linear regulator to a constant 1.5-V value. The circuit operates the LT1084 at slightly above its dropout voltage. To minimize power dissipation, a low-dropout linear regulator was chosen. The LT1084 functions as a conventional adjustable linear regulator with an output voltage that can be varied from 1.25 to 30 V.

Without the preregulator (for a 40-V input and a 5-V output at 5 A), it would be virtually impossible to find a heatsink large enough to dissipate enough energy to keep the linear-regulator junction temperature below its maximum value. With the preregulator technique, however, the linear regulator will dissipate only 7.5 W under worst-case loading conditions for the entire input- voltage range of 15 to 40 V. Even under a short-circuit fault condition, the 1.5-V drop across the LT1084 is maintained.

 Regulator Loss Cutter Circuit Diagram

Regulator Loss Cutter Circuit Diagram
 

Simple Room Ionizer Circuit Diagram

Simple Room Ionizer Circuit Diagram is a voltage multiplier circuit acting as an Ionizer. Its calculated to feed 220V from mains and the output is about 6KV. Caution should take with the circuit as can be dangerous due to mains. You can place a needle at the output 3cm long. Even you disconnect from mains, capacitors can be dangerous so make sure to discharge them by shorting their pins before you touch the circuit with hands. 

Simple Room Ionizer Circuit Diagram

Simple Room Ionizer Circuit Diagram

High voltage Power supply Circuit Diagram

High voltage Power supply Circuit Diagram. A 6 V battery can provide 100-150 Vdc center-tapped at a high internal impedance (not dangerous though it can inflict an unpleasant jolt). A 6.3 V transformer is connected ' 'in reverse'' with a transistor used in a Hartley oscillator configuration. The frequency of operation may be controlled by varying the value of the 10 ohm resistor.The 10 µ¥ capacitor must have a working voltage of at least 250 Vdc .

 High voltage Power supply Circuit Diagram


High voltage Power supply Circuit Diagram

Build a Charger Extends Lead-Acid Battery Life Circuit Diagram

The Charger Extends Lead-Acid Battery Life Circuit Diagram furnishes an initial charging voltage of 2.5 V per cell at 25°C to rapidly charge a battery. The charging current decreases as the battery charges, and when the current drops to 180 mA, the charging circuit reduces the output voltage to 2.35 V per cell, floating the battery in a fully charged state. 

This lower voltage prevents the battery from overcharging, which would shorten its life. The LM301A compares the voltage drop across R1 with an 18-mV reference set by R2. The comparator`s output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-chaiging current passing through R1 drops below 180 mA. the 150-mV difference between the charge and float voltages is set by the ratio of R3 to R4. The LEDs show the state of the circuit . 

Charger Extends Lead-Acid Battery Life Circuit Diagram

Charger Extends Lead-Acid Battery Life Circuit Diagram

Bipolar Power supply for Battery Instruments Circuit Diagram

Bipolar Power supply for Battery Instruments Circuit Diagram. To generate regulated ± 5-V supplies from a pair of dry batteries, the circuit of Fig. 1 is commonly used. In order to give protection from inadvertent reverse connection of a battery, a diode in series with each battery would produce an unacceptable voltage drop. The more effective approach is to fit diodes Dl and D2 as shown in Fig. 2, in parallel with each battery. 

When the supply is switched off, there is the risk of a reverse bias being applied across the regulators, if there is significant inductance or capacitance in the load circuit. Diodes across the regulators prevent damage. When the power supply is switched on, the two switches do not act in unison. There is a probability that one or the other regulators will be latched hard off by the other. To prevent this, D3 and D4 are Zener diodes so that ± 5-V rails are pulled up by the batteries until the regulators establish the correct levels.

 Bipolar Power supply for Battery Instruments Circuit Diagram


Bipolar Power supply for Battery Instruments Circuit Diagram

Build a Voice Scrambler or Descrambler Circuit Diagram

This Voice Scrambler or De-scrambler Circuit Diagram uses an NE602 as an inversion mixer. U2 is set to run at about 2.5 to 3.5 kHz. U3 drives a loudspeaker. Because speech inversion scrambling is its own inverse, the circuit will also descramble . 

Voice Scrambler or Descrambler Circuit Diagram

Voice Scrambler or Descrambler Circuit Diagram

Build a Universal Active Filter Circuit Diagram

The Universal Active Filter Circuit Diagram as shown gives the bandpass operation the transfer function calculated from FBP(s) = where = 1 + s/Qo>0 + s2/w02. The cut-off frequency, 0, and the Q-factor are given by 0 = g/C and Q = gR/2 where g is the trans conductance at room temperature. Interchanging the capacitor C with the resistor R at the input of the circuit high-pass operation is obtained. A low-pass filter is obtained by applying two parallel connections ctf R and C as shown in Fig. 2. The low-pass operation may be much improved with the circuit as given in Fig. 3. Here the gain and Q may be set up separately with respect to the cut-off frequency according to the equations Q = 1/fB = 1 + R2/R!, A = Q2 and 0 = g ffi/C. 

 Build a Universal Active Filter Circuit Diagram


Simple Output-limiter Circuit Diagram

Simple Output-limiter Circuit Diagram HA-5190 is rated for ±5 V output swing, and saturates at ±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 illustrates a feedback limiter, where gain is reduced ifthe output exceeds ± ( Vz + 21j-). A 5-V zener with a sharp knee characteristic is recommended. 

Simple Output-limiter Circuit Diagram

Simple Output-limiter Circuit Diagram

Build a Variable-Frequency Audio Band pass Filter Circuit Diagram

This variable-frequency, audio bandpass filter is built around two 741 op amps that are connected in cascade. Two 741 op amps are configured as identical RC active filters and are connected in cascade for better selectivity. The filter`s tuning range is from 500~Hz to 1500 Hz. The overall voltage gain is slightly greater than 1 and the filter`s is about 5, The circuit can handle input signals of 4 V peak-to-peak without being overdriven. The circuit`s input impedance is over 200 kohm and its output impedance is less than 1 kohm

Variable-Frequency Audio Bandpass Filter Circuit Diagram

Variable-Frequency Audio Bp Filter Circuit Diagram
 

Simple Audio Clipper Circuit Diagram

Simple Audio Clipper Circuit Diagram for use with headphones, this circuit sets the audio clipping level via a 5-KOhmhm pot. This type of noise clipper works best for pulse-type noise of low duty cycle, such as ignition noise. Rl sets the bias on the diodes for the desired limiting level.

 Simple Audio Clipper Circuit Diagram

Simple Audio Clipper Circuit Diagram

Simple Programmable Attenuator Circuit

This Simple Programmable Attenuator 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 usual method of constructing a constant impedance ladder, and switching sections in and out with analog switches. Two identical circuits can be used to attenuate a balanced line .

Simple Programmable Attenuator Circuit

Simple Programmable Attenuator Circuit

Simple Wide band 2 pole high-pass filter

The Simple Wide band 2 pole high-pass filter 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. An equivalent low pass filter is similarly obtained by capacitance and resistance transformation . 

Simple Wide band 2 pole high-pass filter Circuit Diagram

Simple Wide band 2 pole high-pass filter

Super Digitally Tuned low Power active filter

This Super Digitally tuned low power active filter constant gain, constant Q, variable frequency filter provides simultaneous low-pass, bandpass, and high-pass outputs with the component values shown, the center frequency will be 235 Hz and 23.5 Hz for high and low logic inputs. Respectively, Q = 100, and gain = 100.

 Super Digitally tuned low power active filter Circuit Diagram

Super Digitally tuned low power active filter

Voltage Controlled Filter SSM2044P Circuit Diagram

Voltage Controlled Filter 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 distortion sinewave oscillator. No external ladder network is required making the device ideal in polyphonic applications.

 Voltage Controlled Filter SSM2044P Circuit Diagram

Voltage Controlled Filter SSM2044P Circuit Diagram
 
 

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