Battery Indicator schematic diagram

This circuit diagramc shows a simple battery level indicator.In general, in mobile phones, the battery levels is displayed in dot or bar style.This helps you to effortlessly acknowledge the battery level.

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Rain Detector schematic

Here's a simple rain detector circuit. It uses a sensor made of a small piece of etched PC board and a simple SCR circuit to detect rain and sound a buzzer. The SCR could also be used to activate a relay, turn on a lamp, or send a signal to a security system.

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AC to DC Schematic

1. Classic Plus and Minus DC Power Supply - produces both a positive 15v and a negative 15v from a 20vac wall adapter.
2. AC to DC Boost Converter with PFC - Implementation of a AC to DC Boost Converter with power factor correction.
3. Classic Linear 5v Supply Using 6.3vac Transformer - Circuit consists of an iron core transformer, a bridge rectifier, a filter capacitor and a voltage regulator.
4. AC-to-DC converter circuit utilizing IGBTs - AC-to-DC converter furnishing a regulated DC-output voltage from an AC-input supply voltage
5. Non-isolated Off-line AC to DC Power Supply - Efficient circuit can provide up to 100ma of a regulated 5 volts from an AC power.

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Schematic Audio Amplifier Circuit 200W

Output Power : 200Watts
Load Resistance : 8ohms
Input impedance : 55K
Maximum supply voltage : (+95v)-0-(-95v)
Recommended supply voltage : (+66v)-0-(-66v)

This complete aerial quality, low babble address audio ability amplifier is based about the Hybrid Integrated Ambit STK4050 bogus by Sanyo. The ambit incorporates aggregate and has a best music achievement ability of 200W.The ambit incorporates an on lath ability supply; therefore, alone centre broke agent is appropriate to ability the circuit. I t has actual acceptable affection sound. U can use it with your Home Theatre your PC & etc... You can additionally use it as Subwoofer Amplifier.

It is a bunched amalgamation for THIN-TYPE Audio sets. Easy Heatsink architecture to banish calefaction generated in THIN-TYPE audio sets. Constant-Current ambit to Reduce accumulation switch-ON and switch-OFF shock noise. External accumulation switch-On and switch-OFF shock babble muting, Load circumlocute protection, thermal abeyance and added circuits can be tailored-designed.

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Room Noise Detector Schematic Circuit

This circuit is intended to signal, through a flashing LED, the exceeding of a fixed threshold in room noise, chosen from three fixed levels, namely 50, 70 & 85 dB. Two Op-amps provide the necessary circuit gain for sounds picked-up by a miniature electret microphone to drive a LED. With SW1 in the first position the circuit is off. Second, third and fourth positions power the circuit and set the input sensitivity threshold to 85, 70 & 50 dB respectively. Current drawing is 1mA with LED off and 12-15mA when the LED is steady on.

Circuit diagram :

Room Noise Detector Circuit diagram

Parts List :

R1____________10K 1/4W Resistor
R2,R3_________22K 1/4W Resistors
R4___________100K 1/4W Resistor
R5,R9,R10_____56K 1/4W Resistors
R6_____________5K6 1/4W Resistor
R7___________560R 1/4W Resistor
R8_____________2K2 1/4W Resistor
R11____________1K 1/4W Resistor
R12___________33K 1/4W Resistor
R13__________330R 1/4W Resistor

C1___________100nF 63V Polyester Capacitor
C2____________10µF 25V Electrolytic Capacitor
C3___________470µF 25V Electrolytic Capacitor
C4____________47µF 25V Electrolytic Capacitor

D1_____________5mm. Red LED

IC1__________LM358 Low Power Dual Op-amp

Q1___________BC327 45V 800mA PNP Transistor

MIC1_________Miniature electret microphone

SW1__________2 poles 4 ways rotary switch

B1___________9V PP3 Battery

Clip for PP3 Battery

Use :

• Place the small box containing the circuit in the room where you intend to measure ambient noise.
• The 50 dB setting is provided to monitor the noise in the bedroom at night. If the LED is steady on, or flashes bright often, then your bedroom is inadequate and too noisy for sleep.
• The 70 dB setting is for living-rooms. If this level is often exceeded during the day, your apartment is rather uncomfortable.
• If noise level is constantly over 85 dB, 8 hours a day, then you are living in a dangerous environment.

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Pure Class A Headphone Amplifier Schematic

400mW RMS into 32 Ohm load, Single-rail Supply - Optional Tilt Control

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This design is derived from the Portable Headphone Amplifierfeaturing an NPN/PNP compound pair emitter follower output stage. An improved output driving capability is gained by making this a push-pull Class-A arrangement. Output power can reach 427mW RMS into a 32 Ohm load at a fixed standing current of 100mA. The single voltage gain stage allows the easy implementation of a shunt-feedback circuitry giving excellent frequency stability.

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Tilt control:

The mentioned shunt-feedback configuration also allows the easy addition of frequency dependent networks in order to obtain an useful, unobtrusive, switchable Tilt control (optional). When SW1 is set in the first position a gentle, shelving bass lift and treble cut is obtained. The central position of SW1 allows a flat frequency response, whereas the third position of this switch enables a shelving treble lift and bass cut.

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Circuit diagram:

Class-A Headphone Amplifier Circuit Diagram

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Parts:

P1 = 22K Dual gang Log Potentiometer (ready for Stereo)

R1 = 15K 1/4W Resistor
R2 = 220K 1/4W Resistor
R3 = 100K 1/2W Trimmer Cermet
R4 = 33K 1/4W Resistor
R5 = 68K 1/4W Resistor
R6 = 50K 1/2W Trimmer Cermet
R7 = 10K 1/4W Resistor
R8 = 47K 1/4W Resistors
R9 = 47K 1/4W Resistors
R10 = 2R2 1/4W Resistors
R11 = 2R2 1/4W Resistors
R12 = 4K7 1/4W Resistor
R13 = 4R7 1/2W Resistor
R14 = 1K2 1/4W Resistor
R15 = 330K 1/4W Resistors (Optional)
R16 = 680K 1/4W Resistor (Optional)
R17 = 220K 1/4W Resistors (Optional)
R18 = 330K 1/4W Resistors (Optional)
R19 = 220K 1/4W Resistors (Optional)
R20 = 22K 1/4W Resistors (Optional)
R21 = 22K 1/4W Resistors (Optional)

C1 = 10µF 25V Electrolytic Capacitors
C2 = 10µF 25V Electrolytic Capacitors
C3 = 10µF 25V Electrolytic Capacitors
C4 = 10µF 25V Electrolytic Capacitors
C5 = 220µF 25V Electrolytic Capacitors
C6 = 100nF 63V Polyester Capacitors
C7 = 220µF 25V Electrolytic Capacitors
C8 = 2200µF 25V Electrolytic Capacitor
C9 = 1nF 63V Polyester Capacitors (Optional)
C10 = 470pF 63V Polystyrene or Ceramic Capacitor (Optional)
C13 = 15nF 63V Polyester Capacitor (Optional)
C11 = 1nF 63V Polyester Capacitors (Optional)
C12 = 1nF 63V Polyester Capacitors (Optional)

D1 = 5mm. or 3mm. LED
D2 = 1N4002 100V 1A Diodes
D3 = 1N4002 100V 1A Diodes

Q1 = BC550C 45V 100mA Low noise High gain NPN Transistors
Q2 = BC550C 45V 100mA Low noise High gain NPN Transistors
Q3 = BC560C 45V 100mA Low noise High gain PNP Transistor
Q4 = BD136 45V 1.5A PNP Transistor
Q5 = BD135 45V 1.5A NPN Transistor

IC1 = 7815 15V 1A Positive voltage regulator IC
T1 = 220V Primary, 15+15V Secondary-5VA Mains transformer

SW1 = 4 poles 3 ways rotary Switch (ready for Stereo)
SW2 = SPST slide or toggle Switch

J1 = RCA audio input socket
J2 = 6mm. or 3mm. Stereo Jack socket
PL1 = Male Mains plug

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Notes:

• Q4, Q5 and IC1 must be fitted with a small U-shaped heatsink.
• For a Stereo version of this circuit, all parts must be doubled except P1, IC1, R14, D1, D2, D3, C8, T1, SW1, SW2, J2 and PL1.
• If the Tilt Control is not needed, omit SW1, all resistors from R15 onwards and all capacitors from C9 onwards. Connect the rightmost terminal of R1 to the Base of Q1.
• Before setting quiescent current rotate the volume control P1 to the minimum, Trimmer R6 to zero resistance and Trimmer R3 to about the middle of its travel.
• Connect a suitable headphone set or, better, a 33 Ohm 1/2W resistor to the amplifier output.
• Connect a Multimeter, set to measure about 10Vdc fsd, across the positive end of C5 and the negative ground.
• Switch on the supply and rotate R3 in order to read about 7.7-7.8V on the Multimeter display.
• Switch off the supply, disconnect the Multimeter and reconnect it, set to measure at least 200mA fsd, in series to the positive supply of the amplifier.
• Switch on the supply and rotate R6 slowly until a reading of about 100mA is displayed.
• Check again the voltage at the positive end of C5 and readjust R3 if necessary.
• Wait about 15 minutes, watch if the current is varying and readjust if necessary.
• Those lucky enough to reach an oscilloscope and a 1KHz sine wave generator, can drive the amplifier to the maximum output power and adjust R3 in order to obtain a symmetrical clipping of the sine wave displayed.

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Technical data:

• Output power (1KHz sinewave):
• 32 Ohm: 427mW RMS
• 64 Ohm: 262mW RMS
• 100 Ohm: 176mW RMS
• 300 Ohm: 64mW RMS
• 600 Ohm: 35mW RMS
• 2000 Ohm: 10mW RMS

Sensitivity:

• 140mV input for 1V RMS output into 32 Ohm load (31mW)
• 500mV input for 3.5V RMS output into 32 Ohm load (380mW)
• Total harmonic distortion into 32 Ohm load @ 1KHz:
• 1V RMS 0.005% 3V RMS 0.015% 3.65V RMS (onset of clipping) 0.018%
• Total harmonic distortion into 32 Ohm load @ 10KHz:
• 1V RMS 0.02% 3V RMS 0.055% 3.65V RMS (onset of clipping) 0.1%
• Unconditionally stable on capacitive loads

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Simple Ignition Timer Schematic

This circuit is a tester for flywheelbased ignition systems in small aeroplane engines. Basically the same ignition coils are also seen in other small combustion engines used in/on mopeds and lawn mowers  in brief, engines without a battery. The part to be tested comprises a primary coil in parallel with the contact breaker. The timing of this contact breaker has to be adjusted correctly.

Since the coil’s primary has a very low resistance it is difficult to determine whether the contact breaker is open or closed.  However, you can determine that reliably with this circuit, using an LED and a beeper. The circuit is implemented twice because aviation engines (Cessna, Piper and similar) always have two ignitions in parallel to increase reliability. For two-cylinder engines, well the purpose is obvious.

Ignition Timer Circuit Diagram

The circuit consists of a 555 and a few transistors. The 555 supplies a square wave of about 3000 Hz. This signal goes to power transistors T1 and T2; these can supply quite a bit of power and are robust enough to withstand the voltage transients from the big coils. The test connection (K2 and K3 respectively) are connected in parallel with the contact breaker to be tested, which itself is in parallel with the ignition coil. The frequency of 3000 Hz is either short circuited by the contact breaker or if the points are open  is amplified somewhat by the resonance of the coil itself.

This allows you to reliably detect the difference bet ween a closed and open contact breaker, despite the low resistance of the coil, which is in parallel with it. When the contact breaker is open the amplified pulses will turn on T3 and T4 respectively, so that the relevant LEDs turn on and the buzzer will sound. 

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300W subwoofer amplifier schematic

This is an amplifier circuit that is formed from a transistor amplifier miraculous. This circuit is used in the speaker subwoofer with 300W maximum power on each side. To apply it, can be used in the room that is not too large, like the car. And the voltage needed between 25 to 42 Volt DC.

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3 4 W power amplifier schematic

The schematic above is amplifier based on ic TA7211P or TA7212P , circuit above using OT transformer as a booster amplifier again. The amplifier suitable used on outside / field, because by using a transformer OT is identical to the PA amplifier.

Part List :

R  = 1K , 10R , 3K3

C  = 1uF , 10uF , 1n , 68u, 3u3, 2n2 x 2, 100u 

IC = TA 7211P / TA7212P

Technical information :

Max Vcc = 15 VDC

Min Vcc  = 4 VDC

Po            = 3,4 W

Rl            = 8 Ohm

Icco         = 16 mA

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PHILCO PHILIPS PH32S86DG – LED LCD TV POWER SUPPLY REGULATOR and AUDIO OUTPUT SCHEMATIC

Power Supply Regulator Circuit & Audio Output schema_ PHILCO [PHILIPS] PH32S86DG – LED LCD TV 

ICs used [TPA3020 (Audio Output) – D7537R (Power Control)

SMPS SCHEMATIC

AUDIO OUTPUT SCHEMATIC

CLICK ON THE SCHEMATICS TO MAGNIFY

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Echo effect with IC PT2399 schematic

Effect Echo is an electronic circuit that is used to delay sound or make an echo in an audio circuit . Using a circuit of echo is easy enough , we just set on the volume, and gain and trimpot near is rate of 20 K ohm to adjust how the desired echoes. This echo circuit using ic 4558D for additional amplifier and ic PT2399 as a major component that serves to echo , or repeat the sound output on the audio system.

Click image to view larger

 How to use it as follows :
That is initially given the output of the mic input or other equipment. Then turn down the volume, and slowly raised, setting echo effect on the trimpot 20K. If not check back for the damaged to the circuit.

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3 Band Graphic Equalizer schematic diagram

This schematic schema diagram is very simple. Just need a single op amp IC LF351 (IC1) and few passive components.

The component values of this schema are not very critical and can be replaced with nearest values with a little loss on the performance. This feature make it easy to be assembled from your junk box.

The op-amp LF351 is wired to operate in three frequency ranges- high,medium and low. The schema is designed such that the schema produces +/-20 dB boost or attenuation for 50Hz,1KHz and 10Khz by varying POT’s R3, R6 and R9. The maximum amplification for any of these bands at maximum supply voltage is 20dB. The op-amp LF 351 is wired as an inverting amplifier whose response to frequencies 50Hz,1Khz and 10KHz can be varied by adjusting POT’s R3,R6 and R9.

Notes:

• The schema can be operated from 6 to 24 V DC .What I recommend is 12V .
• Use a 12V battery or 12 V DC power supply for the schema.
• All capacitors must be rated 15V.
• A 10uF/15V capacitor must be connected between +ve and -ve pins of LF351 if the power supply is far from the schema. Not shown in schema.

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Schematic Audio Power Amplifier with IC TDA2612

This amplifier circuit based on IC TDA2612 produced by siemens , minimum voltage require for this circuit is 10 Volts and amximum voltage require 35 volts DC. Power output 25 watt with 4 ohm impedance.Frequncy response 20Hz to 20kHz. Quiescent current is 70 mA. This is a mono circuit amplifier. See circuit below :

 

 You can use the circuit above at :

• Car
• Tuner
• Pre amp Head
• Pre amp Mic
• Personal Computer 
• Portable media Player
• etc.

Some advantage of the circuit :

• Fairly high voltage
• Low noise sound output
• Easy to make
• Components are easy to find

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Schematic Audio Amplifier with IC TDA2004

See this circuit below:

Datasheet IC TDA2004

Vcc                = 8-18 V

Pout               = 2X 12 W

RL                  = 2 Ohm

Ft                   = 20hz - 20Khz

Icco                = 65 mA

Package         = SIP1-11

Manufactered = SGS-ATES

Other IC TDA2004 , In this circuit you can use the following IC :

A2000V

A2005V

TDA2005

TDA2005M

MPC2005

Or you can call Persamaan IC TDA2004

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