- 08.10.2014
The stereo volume, balance and tone control on the TCA5550 has the following parameters: Low nonlinear distortion no more than 0.1% Supply voltage 10-16V (12V nominal) Current consumption 15...30mA Input voltage 0.5V (gain at a supply voltage of 12V unit) Tone adjustment range -14...+14dB Balance adjustment range 3dB Difference between channels 45dB Signal to noise ratio...
- 29.09.2014
Schematic diagram transmitter is shown in Fig. 1. The transmitter (27 MHz) produces a power of about 0.5 W. A 1 m long wire is used as an antenna. The transmitter consists of 3 stages - a master oscillator (VT1), a power amplifier (VT2) and a manipulator (VT3). The frequency of the master oscillator is set square. resonator Q1 at a frequency of 27 MHz. The generator is loaded on the circuit...
- 28.09.2014
Amplifier parameters: Total range of reproduced frequencies 12...20000 Hz Maximum output power of mid-high frequency channels (Rn=2.7 Ohm, Up=14V) 2*12 W Maximum output power of low-frequency channel (Rn=4 Ohm, Up=14V) 24 W Nominal power mid-range HF channels at THD 0.2% 2*8W Rated power of the LF channel at THD 0.2% 14W Maximum current consumption 8 A In this circuit, A1 is an HF-MF amplifier, and ...
- 30.09.2014
The VHF receiver operates in the range 64-108 MHz. The receiver circuit is based on 2 microcircuits: K174XA34 and VA5386; in addition, the circuit contains 17 capacitors and only 2 resistors. Oscillatory circuit one, heterodyne. A1 has a superheterodyne VHF-FM without ULF. The signal from the antenna is supplied through C1 to the input of the IF chip A1 (pin 12). The station is tuned in...
Amplifier on a chip STK4048II This is a cheaper analogue of the chip from SANYO - STK4048V.
STK4048II is a microcircuit on which even a novice radio amateur can assemble a professional high-quality amplifier that is not inferior to high-quality industrial transistor amplifiers.
Once, an amplifier with a power of about 100 W was required to “drive” a loudspeaker with a resistance of 8 ohms. After studying the reference books, the choice fell on the microcircuit STK4048II. I am a curious radio amateur and don’t like to repeat myself, but here is a new series of microcircuits for me. STK is criticized for its lack of protection, and praised for its “good sound.” The reference data turned out to be quite scanty, and there are errors in the diagrams. To “not be excruciatingly painful” for a burnt-out microcircuit and wasted money, I advise you to use my recommendations.
The Roman numeral “II” in the designation reflects the harmonic coefficient, in this case - 0.4%. Microcircuits with the number “XI” have a harmonic coefficient of 0.007% in the frequency band 20 Hz...50 kHz. Output power at a load of 8 ohms is 120 W. I haven’t tested the microcircuit at a 4 Ohm load, but, according to reviews on the Internet, it turns out to be 60 W, and it gets very hot. The IC power supply is bipolar, from ±55 to ±75 V. If you look at the structure of the microcircuit (Fig. 1), then, taking into account the external “piping” of parts, we will see a classic UMZCH 80-90s.
Fig.1 Structure of the STK4048II chip
Now about the typical errors in using STK:
1. The gain of the original circuit is 100. This is a lot, and there is a possibility of self-excitation. This is what happened to me, but I was ready for this and reduced the resistance of R7 from 68 kOhm to 20 kOhm (Fig. 2). The amplifier immediately stopped energizing. Some radio amateurs recommend reducing the resistance of R7 to 13 kOhm.
Rice. 2
2. The original circuit uses 5-watt wirewound resistors R10...R13 with a resistance of 0.22 Ohms. Such resistors have high inductance, and the consequences of this for the “sound” are unpredictable. Moreover, the power of these resistors is clearly overestimated. 2-watt metal film ones are quite suitable here.
As my experience shows, the fewer inductances in the audio path, the better sound! The only exception is the LR filter L1-R14 at the amplifier output, which is necessary to compensate for load reactivity. Coil L1 is wound on a mandrel Ф10 mm and contains 18 turns in one layer. Wire diameter - 0.8 mm. There is a resistor R14 inside the coil. All capacitors in the UMZCH circuit and in the power supply are with an operating voltage of 100 V.
The amplifier is additionally equipped with a protection circuit against DC voltage amplifier output and connection delay speaker system(Fig.Z).
This article will tell you how to assemble simple sound amplifier based on integrated circuit STK4362 SANYO company. This UMZCH has the following parameters:
Maximum supply voltage - 50 V
Number of channels – 2
Power – 10W + 10W min, at THD = 1.0%
This amplifier is not suitable for a car due to a power supply other than 12 V, but it will perfectly replace multimedia speakers with a built-in amplifier.
Schematic diagram of STK4326 from the datasheet:
Integrated circuit STK4326, wiring diagram
Not finding a ready one on the Internet printed circuit board it was decided to breed it independently. The board was made in the SprintLayout program.
Integrated circuit STK4326, PCB
After which the printed circuit board was manufactured using the method LUT(laser iron). For etching, a mixture was used: hydrogen peroxide + citric acid + salt. The board in the photo differs slightly from the circuit made in SprintLayout, since after installation some places in the circuit were changed for ease of installation.
PCB for STK4362
The following components were used for installation:
Capacitors
C1, C2 – 470 pf (you can take ceramic or mica);
C3, C4, C5 – 47 uF 50 V (polar);
C6 – 1 µF 50 V (polar);
C7 – 100 uF 50 V (polar);
C8, C9 – 0.47 µF 50 V (polar);
C10, C11 – 220 µF 50 V (polar);
C12, C13 – 1000 uF 35 V (polar);
C14, C15 – 0.1 uF 50 V or more (film);
Resistance
R1, R2 – 4.7 Ohm;
R3, R4 – 120 Ohm;
R5, R6 – 1 kOhm;
R7 – 100 Ohm;
R8, R9, R10 – 100 kOhm;
Ready UMZCH on STK4326
To tin the board and mount the parts, I used solder paste ordered from Aliexpress for 300 rubles. The tube in the photo is enough for more than one board, and this greatly speeds up the process, since it contains flux and solder at the same time.
In the early 90s, AIWA music centers were very popular. For a long time The AIWA ZM-2900 music center served me faithfully. Over time, a laser disc player failed, then a two-cassette tape recorder and a radio receiver. The power amplifier and transformer remained operational.
Electrical diagram music center AIWA ZM-2900 can be downloaded from the attachment.
From all electrical diagram I was interested in the STK419-150 stereo power amplifier, which provided decent power (about 100 W per channel) and good quality sound.
The connection diagram for integrated amplifiers STK419-110, STK419-130, STK419-140 and STK419-150 is shown below.
Resistances R13 and R14 (with a power dissipation of at least 2 W) determine the level of current limitation through the output transistors of the integrated assembly. Inductors L1 and L2 are made by winding one layer of copper coil wire with a diameter of 0.8 - 0.9 mm onto resistors R12 and R13 (MLT 2W). Resistors R16 and R17 with a power of 0.5 - 1W. The power of all other resistors is up to 0.25W.
The main characteristics of stereo amplifiers STK419-110, STK419-130, STK419-140 and STK419-150 are shown in the table.
| Integrated amplifier parameters: | STK419-110 | STK419-130 | STK419-140 | STK419-150 | ||
| Case | H3-20 | H3-20 | H3-20 | H3-20 | ||
| Output stage supply voltage (Vcc2) | min | V | ±25 | ±27 | ±30 | ±33 |
| max | V | ±37 | ±37 | ±42 | ±50 | |
| Supply voltage UN (Vcc1) | min | V | ±36 | ±37 | ±42 | ±50 |
| max | V | ±53 | ±57 | ±65 | ±70 | |
| Quiescent current (Iо) | mA | 60 | 60 | 60 | 60 | |
| Maximum power output (Poutmax) | W | 2x50 | 2x60 | 2x80 | 2x100 | |
| Nominal load resistance (Routnom) | Ω | 6 | 6 | 6 | 6 | |
| Frequency range (Bw) | kHz | 0,020-50 | 0,020-50 | 0,020-50 | 0,020-50 | |
| Input resistance (Rin) | kΩ | 55 | 55 | 55 | 55 | |
| Harmonic distortion at Poutmax | % | 0,2 | 0,2 | 0,2 | 0,2 | |
| Gain (Gv) | dB | 32 | 32 | 32 | 32 | |
| Manufacturer | Sanyo | Sanyo | Sanyo | Sanyo |
To manufacture the power supply of the amplifier, a W-shaped transformer of the music center was used, which has a primary winding of 220 volts, as well as a secondary winding with a common middle terminal (0V), with leads for powering the final stages (20V each) and a voltage amplifier (50V each). The power supply diagram is shown below.
Subjectively, the amplifier sounds more pleasant than the LM3886.
I hope that this information regarding integrated circuits STK419-110, STK419-130, STK419-140 and STK419-150 will be useful for making your own stereo amplifiers.
Best regards,
On the chip STK4048XI. We offer a slightly modified circuit of this amplifier based on STK chips. If the circuit itself remains unchanged, and only the microcircuits from the list below are replaced, you can change the output power of the amplifier audio frequency depending on your needs from 6 to 200 watts. Depending on the marking STK chips they have different level nonlinear distortion: II - 0.2%; V - 0.08%; X - 0.008%; XI - 0.002%.
Approximate layout of radio elements on a printed circuit board:
At all STK chips This series provides high output power and low nonlinear distortion. This allows you to get sound reproduction from the amplifier with high quality sound.
The supply voltage is bipolar from 20 to 95 volts (varies depending on the brand of the microcircuit, see table). Amplifier load is at least 4 ohms; optimal - 8 ohms. The input impedance of the UMZCH is 55 kOhm. The quiescent current is 120 mA. Output current up to 15 amperes (depending on the microcircuit used, see table). ICs of the STK40** series require the use of a radiator with an area of at least 400 mm 2. To effectively remove heat, you can screw the chip onto a heat sink using heat-conducting paste.
The list of microcircuits in the table will be incomplete without mentioning two more markings of this series, which provide an output power of the assembled amplifier of 200 watts. This STK4050II and STK4050V. The recommended voltage for the circuit on these microcircuits is not lower than 66 volts, and the maximum is 95 V.
Assembled amplifier based on STK4050 with an output power of 200 watts:
