Keywords: 360W × 2 amplifier production
Author: Cheng Yumi Yi. Design concept and implementation method (1) Can push 4Ω, 2Ω and other double bass "big food" speakers and various professional boxes of professional large coarse voice circles. (2) Power saving, low noise, small heat generation. (3) Good sound quality, can be suitable for home use and professional use. The implementation of the first point is to have a large push power. Due to the growing trend of the living room area, 100W × 2 or less power amplifier has appeared "strength is not from the heart", so this utility is designed to be 4 Ωq 360W × 2,2Ω time 720W × 2. The implementation of the second point is that the circuit operates in static, which is lowered by a large water-grade capacitor and resistor, so that the amplifier level noise is extremely small. The working state of the circuit determines that the heat generation of the circuit components is small, comparable to the general vanity circuit. The large-scale heat dissipation system is equipped with continuous high power, and the low impedance output is safe and reliable. The third point is the main goal of this active board. It is currently recognized: the sound quality of the A, MOS, and electronic tube, so this active is a sound quality of the A, MOS, and tubes. Second. The implementation of high-power output is high power, first of all, the power supply capacity is large. The power supply configured in this active is a ring cattle that is wound on a ring core having a cross-sectional iron. The first side is 1.0 mm width 484 laps, the secondary side is 1.5 mm double line and around 100 laps. The rectification is two 40A full bridges to make a double bridge rectification, filtering 47,000 UF capacitors + 2 2.7KΩ resistor and connected to the positive and negative power supply, so that the voltage is stable in ± 62V. If the voltage is too high, it can reduce the resistance to 2.2kΩ, and the resistance can be increased to 3kΩ, and the power is 3W. In addition to the power supply, it is necessary to achieve high-power output, especially the "big food" speaker, requiring the power amplifier output current capacity, this active, each channel is selected to perform quasi-complementary output, can drive the DC resistance of 0.5Ω "Grand" speaker. Therefore, 720W × 2 is guaranteed at 360W × 2,2Ω when 4Ω. III. The realization of green environmental protection is to achieve low power consumption, low noise pollution, low-thermal radiation pollution is achieved by the following measures: (1) There is only a small current level working when the active is unloaded, and the power tube base The voltage is only 0.45V, which is basically closed, so it is much more powerful than the general reference to power. (2) This active is determined by the above static principle, so the heat radiation is small. The noise is smaller, even if the ear is attached to the speaker, it can only hear the slight "咝" sound, which is smaller than the general headset noise. Fourth. The realization of the sound quality of the Class A, MOS, and electronic tube is currently recognized by the sound quality of the tubes, MOS, and tubes. Therefore, the optimal circuit design is dynamically optimized, and the bias stream is synchronized with the signal size. Therefore, the sound quality is technically guaranteed. In this case, even if several general MOS tubes are replaced, the increase in sound quality is not obvious. The schematic is given below, as shown in Figure 1. As can be seen from Figure 1, this schematic is quite simple, and more than a generally b class or a MRA-quasi-complementary circuit. By changing a resistor on a circuit board, it is convenient to change between the circuit and the quasi-complementary B class or alante.
Next picture: Circuit principle
Next picture: The power supply is easy to manually work due to the simple and simple trace of this act. The author made the bottom plate line and drill φ1.2mm holes in the solder joint, welded with an inner diameter φ0.8mm copper rivet, and the technical carrier of this circuit board has become a "pure soil" class production, but Duplex welding, repeated welding does not damage the board, which brings great convenience to repeatedly adjust the replacement element. Two "pure soil" amplifier plates are shown in Figure 2, and the four power tube shunt panels are shown in FIG. Component parameters are listed in the schedule. As long as the score is constructed, the part is qualified, the hundred-trials, no adjustable resistance.
Below: Pure Soil Canon Plexigraphy
Below: Power Tube Sports Board
Be
Schedule component parameter table
Bit number
model
Power consumption
Withstand voltage
Current
β (HFE)
Q1 × 2Q2 × 2Q3 × 2
2N5551
0.6W
150V
0.3A
200 ± 1%
Q5 × 2
2SA1013
0.9W
160V
1A
150 ± 3%
Q4 × 2q6 × 2
2SA2383
0.9W
160V
1A
150 ± 3%
Q7 × 2
2SC5198
100W
150V
10A
65 ± 5%
Q8 × 2
2SA1941
100W
150V
10A
65 ± 5%
QF × 24
2SD1037
180W
150V
30A
(30-70) 35 ± 30%
D1 × 2D2 × 2
Luminous tube
Φ5
Tongtong 0.18V
Be
15-1.8V
It is necessary to prompt and point out that the electrolytic capacitance used on the board can be used, not the tantalum capacitance, so as not to affect the sense of layering and high frequency. It is better to use a firing capacitor. (2) 20pf feedback capacitance and 300PF capacitance are made of pressure 100 V domestic mica capacitance, not to use porcelain or polyester capacitance to avoid clutter and phase shift. (3) 0.047UF capacitance can be used in polypropylene varieties, rather than use polyester to avoid high frequency amplification. (4) The transistors used are common varieties, such as using other models, please pay attention to component parameters and security. (5) The more precise value of all components on the board, especially the resistance and pairing tubes. (6) Due to the last stage, up to 24 power tubes are used, the heat sink should be set. Each arm of the author (6) uses a black aluminum alloy radiator of 35 mm × 100 mm × 450 mm, and is fixed to a top cover processed by 730 mm × 480 mm aluminum plate, and is speaking with 4Ω or 2 Ω speaker. After a few hours under the general volume, it is still "cold ice". (7) All data tests were measured by DT890B digital meter.
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