Wiring Schematic Diagram

The first stage of the amplifier is a differential amplifier based on transistors Q1 and Q2. Capacitor C8 is the dc input coupler, C1 R1 limits the input current and capacitor passes high frequency signals. The second stage is the stage driver consisting of transistors Q3 and Q4. Output stage is a complementary push-pull stage based MOSFETs IRF530 and IRF9530.Output attaches the loudspeaker with the inductor L1. Network consisting of R15 and C5 is designed to reduce noise. Capacitors C6 and C7 are the filters of the power supply. R6 is preset to adjust the quiescent current.

The diagram shown here is a MOSFET amplifier circuit 10W of sound that only requires a single source. Single railway material rarely used in power amplifiers class-B. However, for low power applications like this is very thin. Actually I have this circuit a old cassette player is still working and republish as it is. The BD512 and BD522 power MOSFETs is obsolete now and you can use any other power MOSFET game instead of them.



Transistors Q1 and Q2 are connected as a Darlington pair works as a preamp. R3 preset controls the quiescent current, while R2 provides. Output is coupled to the speakers through capacitor C4. Capacitor C5 is the power supply filter and C2 is the input DC decoupling capacitor.

Notes.

• The circuit can be assembled on a vero board.
• Use 30V DC for powering the circuit.
• Do not expect much performance from this amplifier.
• Capacitors C3, C4, C5 must be rated 50V and C2 can be 10V.
• Use a 8 ohm 15W speaker as load.

This circuit is an audio amplifier capable of delivering a decent output power with a minimum no: of the parties, with remarkable sound quality. The amplifier uses a single transistor and two MOSFETs and resistors and capacitors some feedback loop in a small scheme.This can bypass may offer a huge 18Watts into 8 ohm speaker or a speaker 30 W at 4 ohms.



For best performance and stability of some components, high-quality well-regulated DC power supply is needed. This is very essential to reduce noise and achieve a constant output power at different loads. A good voltage regulator capable of delivering CC over 2 Amps @ 40V can be used.You can expect a power supply design very soon here in the food section.

An 30 Watt audio amplifier circuit with TDA2040 shown here. TDA2040 is class AB amplifier monolithic integrated audio Pentawatt available in the package. The IC has a low harmonic distortion, cross low over the distortion and has a built in short circuit protection circuit.

In the circuit of two TDA2040 ICs are connected in BTL (bridge tied load) configuration to provide an output of 30W into a 8 ohm speaker to + /-16V DC. Capacitor C1 is a decoupling capacitor DC input. Network consisting of components R2, C4, R3 provides information to IC1 as R7, C6, R8 network provides information of IC2. Red C5, C9 and R5, R9 provides high frequency stability. Capacitors C2, C3 filters positive power rail while the capacitors C7, C8 filters negative power rail.

TDA2822 is a monolithic integrated audio amplifier can be configured in stereo mode or bridge (BTL). The IC has low crossover distortion, low quiescent current and is available in 16 pin DIP package power. The TDA2822 may be operated from a supply voltage range of 3V to 15V. The main applications are headphone amplifier TDA2822, portable audio, radio, mini headphones, preamp etc. The IC can deliver an output power of 0.65W per channel into a 4 ohm speaker 6V @ HV mode 1.35 W stereo and a speaker 4 ohm high voltage supply 6V @ bridge mode.

IC TDA2822 stereo set shown in Figure 1. The left channel input is applied to the noninverting input (pin 1) of the first built in the amplifier stage and the right channel input is applied to the noninverting input (pin 16) of the second amplifier. The inverting input of these built in amplifiers are grounded separately using 1000uF capacitors (C5 and C6). The amplified outputs (left and right) are available at pins 6 and 11 of the IC. The outputs are attached to the respective speakers, using capacitors C1 and C2 respectively. The branch capacitor resistance (ohms 0.1uF and 4.7) connected via the speakers are designed to improve stability and avoid high frequency oscillations. C7 is the power supply filter capacitor.

The output of the amplifier TDA2822 can be increased by use in mono using the bridge configuration shown in Figure 2. The audio input is applied to the noninverting input of amplifier built for the first time. The non-inverting input of the second built-in amplifier to ground. The inverting input of these amplifiers are based with the C9, C11 capacitor branch. Branches R5, R6 C8 and C10, are to improve stability and avoid high frequency oscillations. Capacitor C12 is used for filtering the power supply

Its a high quality FM receiver circuit based on IC CXA1019 . CXA1019 is a monolithic silicon bipolar radio FM / AM receiver IC for Sony. Built in circuitry within the CXA1019 includes RF amplifier, mixer, oscillator, amplifier, quadrature detection circuit, tuning LED driver control electronic volume, FM detector, etc. HF section is only used in this circuit. The IC can be powered by a figure between 3 to 7 V DC and can lead to an 8 ohm speaker

Here is a simple fire alarm circuit simple based on LDR and a pair of lamps for the detection of fire.The alarm works by detecting the smoke produced during fire.The circuit produces an audible alarm when the fire with smoke



When there is smoke in the light bulb will directly fall LDR.The LDR resistance will be low and therefore the voltage across it (below 0.6 V). The transistor is off and there is enough smoke happens.When to mask the light of the fall of LDR, LDR resistance increases and so do the voltage across the transistor will it.Now empowers ON.This IC1 and the power outputs 5V.This tone generator IC UM66 (IC2) to play music will be amplified by IC3 music.This (TDA 2002) to boost speaker.Resistor R6 is to protect the transistor when it becomes R4 towards the resistance values ​​down. Resistance R2 and R1 form a feedback network for the TDA2002 and C1 couples the feedback signal from the union of R1 and R2 to the inverting input of the same IC.



The diode D1 and D2 in combination falls 1.4 V to give the rated voltage (3.5 V) at UM66. UM 66 can not support more than 4V.

Here is the circuit diagram of simple and easy subwoofer filter which will be operated from a 12V DC supply. Such a circuit is incredibly helpful in Car subwoofer applications. The circuit is nothing however a low pass filter whose pass frequency will be adjusted between 60 to 160 Hz.

The circuit is intended round the TL072 twin BIFET opamp IC. Out of the 2 opamps within the chip, IC1A is wired as a buffer. The left and right audio inputs when mixing is fed to the input of the IC1A using the DPDT switch S1. Switch S1 is that the section control switch which might be used to create the subwoofer in section with different speakers.



When S1 is in position {2, 180 degree phase shift are induced.POT R7 will be used for controlling the level. IC1B forms the low pass filter whose pass frequency will be controlled by adjusting the twin gang POT R13.

Many low pass filter circuits for subwoofer are given here and this can be simply another one. The circuit given here using the opamp TL062 from ST Micro electronics. TL062 is twin high input impedance J-FET opamp that has very low power consumption and high slew rate. The opamp has wonderful audio characteristics and is extremely appropriate for this circuit.

Out of the 2 opamps within TLC062, 1st one is wired because the mixer cum pre amplifier stage. The left and right channel are connected to the inverting input of IC1a for mixing. The gain of 1st stage will be adjusted using POT R3.The output of the first stage is connected to the input of second stage through the filter network comprising of parts R5,R6,R7,R8,C4 and C5. The second opamp (IC1b) is a buffer and also the filtered output is offered at the pin 7 of the TLC062.

This Simple Portable FM transmitter includes a limiter, a microphone amplifier and a PLL digital tuning. All the components are placed on one circuit board. The RF power is switchable between 1 W (HI) and 0,2 W (LO).

The schematic diagram is split into 3 parts: RF part (numbered from 1), PLL (numbered from 30) and audio part (numbered from 50). Connect a 6 V / 0,1 A bulb to the output and set the correct frequency on PLL. Set the RF power to HI. currently activate the transmitter. you must tune it on a receiver. perhaps you may stretch coils of the L1. Fix the L1 in position when the tuning voltage (on Q3) is in range 4-9 V. Then use C15, C16 and C17 to regulate the best power (the highest light of the bulb). Then you'll be able to connect antenna and audio signal. change R1 till the audio sounds as loud because the alternative stations.

The MAX2369 may be a dual-band, triple-mode complete transmitter for cellular phones. The device takes a differential I/Q baseband input and mixes it up to IF through a quadrature modulator and IF variable-gain amplifier (VGA). The signal is then routed to an external bandpass filter and upconverted to RF through an SSB mixer and RF VGA. The signal is additional amplified with an on-board PA driver.

The MAX2369 is meant for dual-band operation and supports TDMA for the PCS band additionally as TDMA and AMPS for the cellular band. the required mode of operation is chosen by loading knowledge on the SPI™/MICROWIRE™-compatible 3-wire serial bus. The MAX2369 then routes the signals to the acceptable ports looking on that band is chosen. The MAX2369 includes 2 RF LO input ports and 2 PA driver ports, eliminating the necessity for external switching circuitry.

The MAX2369 takes advantage of the serial bus to line modes like charge-pump current, high or low sideband injection, and IF/RF gain balancing. it's packaged in an exceedingly tiny (7mm x 7mm) 48-pin QFN package with exposed paddle.

The image below shows a Block diagram of the entire mixer that includes four Input Amplifier Modules followed by four in-out switchable Tone management Modules, one stereo Line input, four mono Main Faders, one stereo dual-ganged Main Fader, four Pan-Pots, a stereo Main Mixer Amplifier Module and two additional Tone management Modules switchable in and out for every channel, inserted before the main Left and Right outputs.

The basic arrangement of this circuit comes from the recent Quad magnetic pick-up cartridge module. The circuit was rearranged to address microphone input and a single-rail low voltage provide.

This low-noise, absolutely symmetrical, two-transistor head amplifier layout, allows the utilization of a traditional FET input Op-Amp as the second gain stage, even for terribly sensitive microphone inputs.

The voltage-gain of this amplifier is varied by suggests that of R9 from 10 to one hundred, i.e. 20 to 40dB.

This is a really easy 2-way intercom circuit primarily based on a LM390 audio amplifier circuit . the intercom circuit is a stand-alone electronic communications system intended for limited or private dialogue. For this circuit you'll use a 8 ohms speaker, one for each station and require a vi volts dc power offer. Gain management will be done by capacitively coupling a resistor (or FET) from pin vi to ground.

The LM390 Power Audio Amplifier is optimized for 6V, 7.5V, 9V operation into low impedance loads. The gain is internally set at twenty to stay the external part count low, however the addition of an external resistor and capacitor between pins 2 and vi wil increase the gain to any value up to 200. The inputs are ground referenced while the output is automatically biased to at least one 0.5 the provision voltage.