High Impedance amplifier circuits

Mini High Impedance Amplifier is an amplifier with 1 Watt and have a very high input impedance. The series amplifiers can have a very high input impedance because the use of two transistors in the input that is placed Darlington. Input impedance circuit amplifier achieves 20M Ohm. Mini High Impedance Amplifier circuit uses four transistors and an IC 741. Gain amplifier with high input impedance , we can provide the input signal from device with weak levels though.

Mini High impedance amplifier circuit is very cheap to make and quite simple. This amplifier circuit use 9VDC power supply.

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Digital High Low Logic Tester Circuit diagram

1. 
   When the input signal is logic 1, the display shows H’ and the loudspeaker emits a note which is an octave higher than the low’ tone. Operation of the circuit can be seen from the circuit diagram in figure 1 and the truth table in figure 2. When the input signal is 1, transistor T1 conducts taking the input of gate N2 above the trigger threshold and the trigger output goes to logic 0.
2. This is not our first high and low tester, but the present circuit offers something new: a seven-segment display which shows ’H or ’L’ and at the same time a small loudspeaker emits a corresponding tone.
3. lf required, the loudspeaker can be switched on by means of S1. The switch can, of course, be omitted if the audio tone is always required. lf you have an ear for music, R10 and R12 may be replaced by a 220 Q resistor and a 2509 preset potentiometer so that the tone can be adjusted to your particular liking.!
4. And all that at very reasonable cost.
5. When the supply is switched on, the decimal point of the display lights and indicates that the unit is ready For use. lf this is not the case, or an undefined signal is applied to the input, the display, apart from the decimal point, remains dark and the loudspeaker remains silent. lf the input signal is logic O, the display shows ’L’ and the loudspeaker emits a low note.
6. When the input signal is logic 0, T1 is cut off and T2 conducts. The voltage at the inputs of gates N1 and N2 are below the trigger threshold and both outputs are logic 1, switching on transistors T3 and T4; the emitter voltage of T4 rises and cuts off diodes D4 and D5. This causes a current to flow through segments d, e and f, diodes D2 and D3, resistor R6 and transistor T3.
7. With non-defined inputs (between 0.8.. . 2.15 V) and an open circuit input, both input transistors are cut off, The output of N1 is then logic 0 and that of N2 is logic 1: no current can therefore flow through any of the segments. As regards the drive for the two oscillators, suffice it to say that during low inputs N3 is driven by the output of N1 and during high in- puts N4 is driven directly by T1.
8. Transistor T2 (PNP!) is cut off, the input of gate N1 is also above the trigger threshold and this trigger output is therefore also logic 0. Both switching transistors T3 and T4 are off and a current flows through the corresponding segments (b, c, e, f, g), diodes D4 and D5 and R7. 

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Delay and Music Power Supply Circuit with High and Low Voltage

Delay and Music Power Supply Circuit with High and Low Voltage

Voltage variations and ability cuts abnormally affect assorted equip- ment such as TVs, VCRs, music systems and refrigerators. This simple ambit will assure the cher accessories from aerial as able-bodied as low voltages and the voltage surges (when ability resumes). It additionally gives a accordant tune back mains ability resumes. Back mains voltage is normal, the DC voltage at the cathode of zener diode D4 is beneath afresh 5.6V. As a aftereffect transistor T1 is in off state. The DC voltage at the cathode of zener diode D5 is greater than 5.6V and as a aftereffect transistor T2 is in on state. Consequently, broadcast RL1 gets energised, which is adumbrated by lighting up of blooming LED. Under aerial mains voltage condition, transistor T1 switches to on accompaniment because the voltage at cathode of zener diode D4 becomes greater than 5.6V. Consequently, transistor T2 switches to off state, authoritative the broadcast to de-energise Under low mains voltage condition, transistor T1 switches to off accompaniment and as a aftereffect transistor T2 additionally switches to off state, authoritative the broadcast to de-energise.

Timer IC 555 in the ambit is configured to accomplish in a monostable mode. The beating amplitude is about 10 abnormal with the timing basic ethics acclimated in the schema. Back the ability resumes afterwards a break, pin 2 of IC 555 goes low briefly and this triggers it. Its achievement makes music IC UM66 to accomplish through transistor T3. Simultaneously, transistor T1 additionally gets advanced biased as the monostable IC1 achievement is affiliated to its abject via diode D8 and resistor R7. As a result, transistor T1 conducts and biases transistor T2 to cut off. Thus broadcast RL1 charcoal de-energised for the continuance of address beating and the amount is adequate adjoin the voltage surges.

To acclimatize presets VR1 and VR2, you may use a manually capricious auto-transformer. Set the achievement of auto-transformer to 270V AC and affix it to the primary of agent X1. Acclimatize preset VR1 such that broadcast RL1 aloof de-energises. Next set the achievement of auto-transformer to 170V AC. Now acclimatize preset VR2 such that broadcast RL1 afresh de-energises. Aggregate ascendancy VR3 may be adapted for the adapted achievement aggregate of the tune generated by IC UM66

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5V High Current Regulated Circuit

5V High Current Regulated Circuit

Since the accession of the 3-pin regulator ICs in the market, the affair of designing ability accumulation diagram has become beneath and beneath discussed. However, the aforementioned new ICs absolute the types of ability diagram actuality congenital in amusement labs to about 1 ampere units. In addition, ability stages are required, because aerial accepted (5A or 10A) voltage regulator ICs are actual expensive. This is the capital acumen why hobbyists usually opt for a detached solution. The abstraction of cascaded ability stages are absolutely not that bad. For this reason, we accept acclimated detached apparatus for the ambit featured above.

This regulator ambit was advised for microcomputer systems and added applications that crave beating aggressive ability accumulation while carrying aerial accepted achievement at the aforementioned time. The 723 IC acclimated in this architecture is broadly replaced by the new 3-pin regulators. However, the 723 IC is adjustable and its abstruse abstracts are bigger in some points. It is configured in the ambit to achievement voltage levels from 2V to 7V. The bare ability is produced by acceleration the voltage akin through a voltage doubler schema, afterlight it, and acclimation it with a 3-pin regulator IC.

This acutely complicated address is actuality activated actuality to accumulate the voltage akin as low as accessible at the accessory ambagious of the transformer. This makes it accessible to accumulate the ability amusement at transistors T1 and T2 as low as accessible too.

The calefaction bore for T1, T2 and T3 charge be appropriately dimensioned. A calefaction attrition of about 2�C (C F) is recommended. For the aforementioned reason, the resistor ethics for R1, R2 and R2 charge be produced by base resistors in parallel. For R1 and R2: affix two 0.33 ohms (5watts) in alongside for each. For R6: affix two 0.22 ohms (5watts) in alongside by a accepted achievement of 6 amperes; or affix three 0.22 ohms (5watts) in alongside by an accepted achievement of 8 amperes. As added assurance measure, adhesive these resistors on the pcb with some ambit from the board.

If one desires to abolish the voltage doubling, aloof abolish the apparatus D1, D3, C3, C4 and move the diode D2 to the absolute DC band as apparent by the dotted band in the Diagram 1.0. Additionally, the achievement voltage of the agent charge be added , and the ethics of C1, C2, R4 and R5 adapted appropriately.

This ability supply�s voltage achievement drops, by a amount of 0.85 ohms, from 5.5 volts to 5.32 volts. That after-effects to a accepted achievement of about 8 amperes! The voltage bead is aloof 3.3%! The ripple DC voltage is alone beneath than 28 mVeff at the output.

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Variable High Pass Filter Wiring diagram Schematic

This Variable High-Pass Filter Circuit Diagram second order filter which should prove useful in audio applications uses an LM1458 or other similar of op amp. It is tuneable from 30 to 300 Hz cutoff. R2a, b are ganged log-taper potentiometers. 

Variable High-Pass Filter Circuit Diagram

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Build a High Voltage Inverter Wiring diagram Schematic

The High Voltage Inverter Circuit Diagram converts a de voltage (V +) to a high-amplitude square wave in the audio-frequency range. The dual timer, IC2, provides an inexpensive alternative to the traditional transformer for providing complementary base drive to the power transistors, Ql and Q2. You can convert a 6 to 12 V battery output, for example, to an ac amplitude, which is limited primarily by the power rating of transformer Tl. 

Connect timer IC1 as an oscillator to provide a symmetrical square-wave drive to both inputs of IC2. The timing components, R2 and Cl, produce a 2.2-kHz output frequency. By connecting half of IC2 in the inverting mode and the other half in noninverting mode, the timer`s outputs alternately drive the two transistors. 

 Build a High Voltage Inverter Circuit Diagram

You can operate the audio-output transformer, Tl, as a step-up transformer by connecting it backwards using the output winding as an input. The transformer delivers an output voltage across RL of 4 x N x V+V pk-pk, where Nis the transformer turns ratio. For the schema shown, the output swing is 100 x V+V pk-pk.

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LH003Wideband 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.

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Pre regulated High Voltage Power Supply Wiring diagram Schematic

This Pre-regulated High Voltage Power Supply Circuit Diagram triacs selects the tap on main transformer Tl, which provides the proper, pre-regulated voltage to the secondary regulator. T2 and its associated components comprise the secondary regulator. The ADC 0804, IC1, digitizes a voltage-feedback signal from the secondary regulator`s output. 

 Pre-regulated High Voltage Power Supply Circuit Diagram

The MC1415 De-multiplexer, IC2, decodes the digitizer`s output. IC2, in turn, drives Tl`s opto-isolated triacs via the 74LS240 driver chip, IC3, and associated opto-isolators. Transformer T3 samples the schema`s current output. The auxiliary, 12 V winding on Tl ensures noload starting. The combination of op amp IC5 and the inverting transistor, Ql, square this current signal. 

The output of Ql is the CLK signal, which triggers one-half of the one shot, IC4A, to begin the schema`s AID conversion. The one shots` periods are set to time out within 1l2 cycle of the ac input. Upon completion of its AID conversion, ICl`s INTR output triggers the other half of the one shot, IC4B, which enables the converter`s data outputs. The rising edge of the CLK signal resets the one shot and latches the new conversion value into IC2. The latch, associated driver, and optoisolator trigger a selected triac according to the latest value of the voltage-feedback signal, V, . Keep enjoying dont forget click on share button .

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High Power LEDs up to 15 Amperes Wiring diagram Schematic

This High Power LEDs up to 15 Amperes Circuit Diagram employs a simple scheme that limits the current flow to the LED, you can easily modify the schema, and can change the power just replacing the value of R2. You can use a DC source of any tensions between 9V to 15V.Para powers or other LEDs just use the approximate formula:

Current (I) = 0.8/R2 where I is the current specified by the LED manufacturer. Value of I this conductor is 10A. Use R2 = 0.8/Current formula (I) to determine R2.

High Power LEDs up to 15 Amperes Circuit Diagram

Parts List

Q1 2N3055 or similar NPN transistor

R1 1W 220ohms

D1, D2 1N4001 silicon diode or rectifier

See R2 power for each LED

R2 for 1W LED 1W 2.7ohms

R2 LED to 1.5 ohms 1W 3W

5W LED R2 to 0.6 ohms or 2 x parallel 1.2-ohms/1W

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