"Related character: 25 W. Establishment
Source Source Distance: http://www.geocities.jp/team_zero_three/poweramp/index.html
Some parts of the text, the original item, and the direct adoption interval.
I was wrong again (sweat. First of all, please do the latest schematic.
20 [W] DC Power Amplifier v2.6 (completed!?)
Introduction Correction. Bias Circuit Q7 The area around his V2.5 did not work well. After that the value of the resistance is low, this side did not know the proper design method, so actually, the circuit is actually set, and when the maximum amplitude is exceeded 18 [V] to 19 [V] ~ 19 [ V] decided to clip in a well-balanced manner.
I actually assembled the circuit on a universal board, but since I oscillated, he put a capacitor for oscillation to Q5 and Q6. Although 68 [PF] in the schematic, I connected 33 [PF] parallel to 66 [PF] (33 pF).
When I listen to the sound, it is quite good. I felt that I was strongly output from low to high. I use satellite systems (Sub-Woofer is in the middle, a system in the middle of the middle and high regions), but even if the frequency characteristics should be flat in the audio band, the low band is too strong (?) I will come out enough. Meanwhile, high bands are also high-hat sympsbal and vocal breath, and voice high frequency components are exaggerated and heard. This may be due to a crossover network that is in the speaker. There is also a hand to get rid of it, but I thought that the manufacturer had a crossover network, but I thought that there should be a basis for that, and I decided to respect it. It is dash if the basis of the manufacturer is removed in his own sense and getting worse. Well, it's a satellite system, and I think this is such a maker. When I was dissatisfied with the speaker, I think that it is also about to connect a newer who made a beginner to a high speaker .... Surely I think this is just good. This time, I did not use any parts for audio, but the person who made it was a surprisingly good sound. However, I was tired that I was listening to two hours because the speaker's low and high-pass arguments are too strong. It may be good to see movies.
I have planned and implemented amplifier production from early summer, but it was completed with ¥ 30,000, including research, development, design and production. I think it was quite economic. However, I had time and I had a hard time ^ ^ ;. Oscilloscopes were rolling to a certain place and borrowed it because there was no evidence used for around 10 years. There are also things that are written by "Tester alone easily," in the amp production book, but when I tried it, I felt tough only with the tester. It may be good to make the same thing with a book, but if you live around Akihabara, it is very difficult to obtain parts as a real problem. Therefore, a circuit configuration is determined to some extent, and the number of wattles and available parts is examined, and then the circuit constant is decided, but it is also necessary to confirm the validity of the operation as well. . I think this is impossible without oscilloscope. It is a person who can be made with only the tester that the design of the circuit can be done and has a know-how of the production. I think that a beginner says, "Tester alone can be easily made with tester." Or is my generation human beings just can not make things?
If there is an opportunity, I would like to listen to the photograph of the completed amplifier and the crew of the area and surveyed questionnaire.
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"" Do It Myself "" Audio Stereo Amplifier Production 2001.11.8
The order is later, but it is the power supply circuit of this project.
POWER SUPPLY V2.1
If you are using the 3-terminal regulator above, it is a power supply circuit for voltage amplification stage. If the voltage amplification stage does not constant voltage, it seems that the noise of a low sound that is likely to be boued (mere design mistakes are also others). I did not use a constant voltage power for the amplifier made before making a good change, but this noise was firmly out.
This time, I used a 3-terminal regulator because there was no margin for the ability to design discrete and confident and time to design a deskty voltage power supply circuit. Two transformers of 24 [V] 0.5 [A] are used as power supplies for voltage amplification stage. The primary side is parallel, the secondary side is connected in series, and a positive and negative 2 power supply is configured. Because the voltage amplification stage does not consume 100 [MA], no large heat sink is required. I made a big deal, but it is so cold when I touch it during operation.
The lower one is a power supply circuit for power amplification stage. Transformer uses two transformers of 22 [V] 3A. This is also the primary side, in parallel, the secondary side is connected in series and constitutes a positive and negative 2 power supply. Here is a relatively large amount of power, but in that case, the large smooth block capacitor is placed in parallel so that the ripple is sufficiently small. In the schematic, the voltage after smoothing is also 22 [V], but the actual voltage is 22 * SQRT (2) to = 31 [V]. However, when this is a voltage when the current is hardly flowed, the maximum 3 [A] also flows, probably to the vicinity of 22 [V] (not checked).
This time, I made a 4 power supply with 4 transformers. Well, I did not get the appropriate transformer easily and happens that the transformer of 22 [V] 3 [A] was sold at 1 piece in the digit. Initially, he had in advance he was about 13 [V] 1 [A] transformer, but he was going to make an amplifier of about 5 [W], but this he is 22 [V] 3 [A] I found a transformer of \ 300, and changed the plan much.
If you use many transformers, we feel like spent more than half of all processes, such as processing and implementation of cases. If the transformer is large, the wiring will always pass near the transformer, so I was worried that I was not able to pick up extra noise from the transformer, but from the completed amplifier, even if I get my ear close to the speaker, noise I could not hear at all.
Currently, it is used by connecting to a PC sound card, but noise from the sound card is very large, and it is good to say that there is no noise of the amplifier itself compared to this. To test the amplifier, I created a sine wave or a square wave with a PC and played this from a sound card, but when the waveform is observed, the square wave is very distorted. After all, the sound quality like a CD deck can not be expected with a sound card of about 5,000.
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"" Do It Myself "" Audio Stereo Amplifier Production Later 2001.11.18
I took a picture of the amplifier. I will put it directly here.
"Do It MySelf" "20 [W] +20 [W] Audio DC Power Amplifier v2.6
"Do It Myself" "20 [W] +20 [W] Audio DC Power Amplifier V2.6 From Top
It is a smoothing capacitor of the power supply of the output stage that is rising like a tower on the left and right of the middle. Each positive and negative is smoothing with 30,000 [UF]. It is a capacitor of 50 [V] 10,000 [UF] that is behind the middle. As a beginner, I want to make a condenser and implement a condenser using a condenser band (laughs). That's why I have done it with Shikkari, but I feel that it is space-like to be stuffed into the back of the case.
He was purchased at the digits of Osaka Nihonbashi except MOS-FET 2SK1058 / 2SJ162. However, instead of 2SK1058 / 2SJ162, there may be stock of a 2SK2458 / 2SJ440 complementary pair. When I went, he was out of stock in 25244. Why is his MOS-FET for audio output sells only one way, but it is a bit question .... 2SK1058 / 2SJ162 purchased from mail order from Satot electricity. Also, the 22.d-V3 [A] \ 300 used for the output stage is still not known whether there is stock. If not, the transformer of 20 [V] 2 [A] can be purchased instead (20 [W] +20 [W] Amp written). However, I think that this was 4,000 or more.
The MOS-FET at the output stage does not compensate for temperature. MOS-FET seems to be said to be unnecessary temperature compensation, but if you do not do this, it is not very good in the plane of the topic. I think that it is okay because the source resistance of 0.33 [OHM] is inserted .... The idling current is 300 [ma], but when it was powered on and there is no longer a long time, the heat sink will be hotter than after it (50 [° C]?). Now I'm thinking of measuring with a thermometer.
The substrate in the middle is implemented with a resistor of 0.33 [OHM] 3 [W] for power supply and 0.33 [OHM] 3 [W] for output, and about 1UH coil for oscillation measures and 10 [OHM] 3 [W]. increase. This time, I used a rectifier diode without using a rectifier. In fact, I think this board was not the case in the case, but it was better to implement on the back side. The yellow and red lines in the front are coming from the secondary side of the transformer, but after rectifying this, it is wired again to the back of the case to connect to the smoothing capacitor. Then it was good if it was connected back from the beginning ... I think it's a later festival.
The front of the previous heat sink is equipped with 22 [V] 3 [A] \ 300 used for the output stage. There are two substrates with a small heat sink at the back, but this is a 3-terminal regulator of 24 [V]. The left side is +24 [V], and the right is -24 [V]. Even if it comes to a small heat sink, it was too cold, so this was too big because it was quite cold. I think it is enough with the most small heat sink for TO-220.
"Do It MySelf" "20 [W] +20 [W] Audio DC POWER AMPLIFIER V2.6 Case Wiring
The back of the case is like this. The left and right largest in the example \ 300 transformer, the two in the middle are power transformers for voltage amplification. The wiring is messy. It feels like a beginner but not about being refreshed. The two substrates above are voltage amplification units. "
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