TDA7560 Car Amplifier Circuit

TDA7560 is a 4 x 45W QUAD BRIDGE CAR RADIO AMPLIFIER PLUS HSD. The TDA7560’s inputs seem to be ground-compatible and can stand quite high input signals (± 8Vpk) with other out any performances degradation. If the basic} value in to the input capacitors (0.1mF) is adopted, the low frequency cut-off will amount to 16 Hz.

The TDA7560 is a breakthrough BCD (Bipolar / CMOS / DMOS) technology class AB Audio Power Amplifierin Flexiwatt 25 package designed for high power car radio. The completely complementary P-Channel/N-Channel output structure allows a rail to rail output voltage swing which, combined with other high output current and minimised saturation losses sets new power references at the car-radio field, with other unparalleled distortion performances.

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20W Bridge Amplifier with TDA2005

TDA2005 is a 20W amplifier is a bridge to the car radio. The TDA 2005 is ClassB dual audio power amplifier in MULTIWATT) package specifically designed for car radio applications: power booster amplifiers are easily designed with this device that provides a high current capability (up to 3.5 A) and that can handle very low impedance loads (up to 1.6 W).

TDA2005M is designed to bridge TDA2005S applications for music application. With TDA 2005S can build a 2 x 10watt stereo amplifier circuit 2 x 2Ω speakers with 10% distortion.

TDA 2005 maximum ratings

Operating Supply Voltage 18 V
DC Supply Voltage 28 V
Peak Supply Voltage (for 50 ms) 40 V
Output Peak Current (non repetitive t = 0.1 ms) 4.5 A
Output Peak Current (repetitive f . 10 Hz) 3.5 A
Power Dissipation at Tcase = 60 °C 30 W
Storage and Junction Temperature – 40 to 150 °C

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5 Watt Class-A Audio Amplifier

On the day of the old valve, most commercial audio amplifiers suitable for compact integrated single discs or players used stereo amplifier topology of a single valve. The circuit is usually carried out through a multiple type valve, for example, a triode pentode ECL86.

Common features of the amplifiers are Class A operation, the output power in the 3 - 5W range, input sensitivity of about 600mV of total output power, THD of 3% @ 1KHz and 3W. Best types showed figures of 1.8% THD @ 3W and 0.8% @ 2W.

This solid-state push-pull single-ended Class A circuit is capable of providing a sound comparable to that of tube amplifiers, offering more output power (6.9W measured across a load of 8 ohm speaker cabinet), less THD, higher input sensitivity and better linearity.

Voltage and current for this circuit is 24 V and 700 mA, respectively, compared with 250 HT rail and 1A@6.3V heating filament of the valve works with amplifiers. The penalty only for the transistor circuit that works with the need for a larger heat sink for Q2 and Q3 (compared with the maximum power delivered). In any case, the amount of heat generated by this circuit can be comparable to that of a single valve amplifier. A choice of low-boost facility can be added through R5 and C5.

This circuit was built and compared with a circuit of a valve box phonograph in the early 1950 by Aren van Waard, a Dutch biochemist working in the field of medical imaging (PET) with a strong interest in audio amplifiers valve. A complete description of the circuits and test results of subjective comparisons made by the distinguished author appeared in the magazine AudioXpress: February, March and April 2005 issues.

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20W Audio Amplifier using LM1875

This is just another 20W audio amplifier circuit, but this time based on LM1875 audio amplifier IC from National Semiconductor. With a dual power supply 25V LM1875 can deliver 20W of audio power into a 4 ohm speaker. The LM1875 requires fewer external components and has a very low distortion. The IC is also filled with a number of cool features, like the upload speed fast, wide range power supply, high output current, high-swing output voltage, thermal protection, etc. The IC is available in TO -220 plastic power package and is very suitable for a variety of applications including audio systems, servo amplifiers, home theater systems, etc.

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Automatic Amplifiers Cooler Fan

The schematic of an Automatic Amplifiers Cooler Fan is given here. The circuit automatically turn on the cooler fan whenever the temperature of the heat sink exceeds a preset level. This circuit can save plenty of energy becausef the cooler fan are going to be OFF when the amplifier is running on low volume. At low volume less heat are going to be dissipated and it'll not trigger the cooler fan ON.

The temperature is sensed using an NTC (negative temperature coefficient) thermistor R2. Junction of thermistor r2 and resistor R1 is connected to the inverting input (pin3) of IC1 that is wired as a comparator. The non-inverting input (pin2) is given with a reference voltage using the preset R3. As temperature will increase the resistance of NTC thermistor can drop and so do the voltage across it. When the voltage at the inverting input becomes but that of the reference voltage (set for a selected threshold temperature) the output of the comparator goes high and switches the transistor Q1 ON. this can activate the relay and the cooler fan are going to be switched ON. When the temperature decreases the reverse happens. LED D2 can glow when the fan is ON. Diode D1 could be a freewheeling diode.

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Mini Audio Amplifier Circuit using IC KA2209

This is 2X1W audio amplifier circuit with mini-KA2209 IC. It may work well from 3-12V DC and will work from a battery since the quiescent current drain is low. It requires no heat sink for normal use. Input and output are both ground referenced. Maximum output is obtained with a 12V power supply and 8 ohm speaker, however, is especially suitable for driving headphones from a supply as low as 3V.

Amp mini circuit only a few external components, the IC contains most of the necessary circuits. R1, R2 and R3, R4 are the resistances of feedback. C1 provides power supply decoupling. C2 and C3 are the input coupling capacitors, which block any DC that might be present on the inputs. C4, C5 DC block in the feedback loop of the inverting input and C6, C7 are the output coupling capacitors. C8, C9 and R5, R6 act as a Zobel network to provide a high frequency load for stability in the frequencies where the inductive reactance of the loudspeaker can be strong too. The boat provides the attenuation of input level.

KA2209 - Audio Amplifier Circuit Component

C1,C2,C3    : 10 uF/25V  ecap
C4,C5       : 100 uF/16V ecap
C6,C7       : 470 uF/16V ecap
C8,C9       : 100 nF     poly
R1,R3       : 1k     Resistor
R2,R4       : 100R   Resistor
R5,R6       : 4R7ohm Resistor
Pot1        : 10k dual gang log pot
IC1         : KA2209 Integrated Circuit

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