DIY a typical stereo RF power amplifier (TDA2030A)
The stereo power amplifier integrated circuit TDA2030A is mainly composed of a stereo amplifier , which uses a typical power amplifier circuit, with little distortion , fewer external components , high stability , wide frequency range , high fidelity , power , etc. advantages , while using quad op amp GL324A input audio signal processing and high , bass control , and thus more to ensure the sound output quality. This is a very suitable radio enthusiasts and audiophiles homemade stereo sets timber . The PA actual listening , soft and delicate treble , bass plump mellow.
First, the working principle
The stereo power amplifier used in the core of the chip is an international high-fidelity audio power amplifier integrated circuit TDA2030A. The circuit consists of three parts , namely, the power circuit, power amplifier , and input signal processing power left and right channels ( quad op amp ) . 220V AC power adapter will be reduced dual 12V low-voltage alternating current , after the bridge rectifier becomes ± 18V DC , as op-amp amplifier and power supply , D5, R29 integral power indicator circuit to indicate that the power is normal, switch K is power switch.
Quad Operational Amplifier GL324A ( or LM324) and peripheral components is high, the bass control processing circuit circuit and audio input signals , C16, C18 are the input coupling circuit two signals , W1 is a two- way bass control potentiometer , W2 are two Road treble control potentiometer , C25, C26 is the output coupling capacitor . GL324A of 4 feet and 11 feet respectively, the positive and negative terminals of the power supply , 3,5 feet ground.
Two power amplifier integrated circuit using a TDA2030A, which one is the positive input pin , pin 2 inverting input , C3, C6 , respectively, for the left and right inputs of two coupling capacitors , R1, R4, C2 constitute the negative feedback circuit IC1 , R6, R7, C5 IC2 constituting a negative feedback circuit to enhance the sound quality . Its 5 feet, 3 feet respectively connected to the positive and negative power supply , 4 -pin as an output , then 4Ω speaker load , its effective power up to 20W, W3 is a two -way balancing potentiometer , W4 is a two -way volume potentiometer .
Second, welding and installation
Usually the first load low, heat-resistant components , and finally installed integrated circuits. The following steps should be welded with the installation: ( 1 ) the quantity and quality of components inventory and timely replacement of defective components ; ( 2 ) to determine the components of the pitch installation, using horizontal mounting resistors , capacitors Polyester electrolytic capacitors vertical installation , and are required to close the circuit board. ( 3 ) Cartridge IC1, IC2 caution feet fully inserted before welding, and pay attention to the heat sink with the holes coincide . Each tin solder heating time and the amount should be appropriate to prevent solder false and short , cut off the excess after welding pin and check all joints , after confirmation test before electricity . Also note that the power transformer primary , secondary and wiring switches and circuit boards , without fail , IC1, IC2 with self-tapping screws and radiator are connected .
Third, test and assembly
1 , power test
After all the components and plug- welded , after carefully checked before the live test with a multimeter to measure DC voltage profile positive and negative power supply should be about ± 18V, light-emitting diodes D5 light, after connecting frets , hand touch inputs IN1, IN2, the sensor should be strong signal that the circuit is normal . If there is no strong sense signal , indicating that the amplifier circuit is not working , need further examination IC1, IC2, IC3 and peripheral components to install welded properly.
2 , machine assembly
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