โมดูลขยายเสียง 35W OEP30W Mono Digital Power Amplifier Class D 8-24V

• SP- SP+ : ต่อลำโพงขั้วบวก ลบ
• VCC , GND : ต่อไฟเข้า 8-24V
• IN+ , IN- : ต่อสัญญาเสียงเข้า
• CS : สำหรับเปิดปิดโมดูลขยายเสียง ถ้าต่อลอยเปิด / ต่อลงกราวน์ปิด

36dB power amplifier gain benefits : because some audio equipment sound source signal is too weak, using 36dB amplifier to amplify the sound will be very large, using the market 20dB amplifier to amplify the sound will be very small. For example, the audio signal output from the mobile phone is weaker than the audio signal from the computer, and it is very loud to amplify the sound with a 36dB power amplifier. If the computer audio signal is connected, the 36dD amplifier is used to amplify the sound is too loud, and the sound is distorted. You should lower the volume of the computer. If the computer is not convenient to adjust, you can short the 26dB pad on the amplifier board, so the volume is much lower Or, input the series resistance in the power amplifier board to reduce the volume (the input resistance of the power amplifier board is 1K, use the series 200-1000 ohm resistor divider to change the power amplifier volume, so that the power amplifier will not have amplification saturation distortion), so that the amplified sound is not distorted, not unpleasant .

The power amplifier gain uses 36dB. The disadvantage: if the audio equipment has a weak noise signal when it is muted (no sound is played), the noise will be greatly increased through the 36dB power amplifier, so some customers say why the power amplifier is very loud without sound (because The noise comes from the input signal source. There is no noise when the input audio cable of the power amplifier board is disconnected in the speaker.) The26dBgain pad ofthe power amplifier isshorted to improve the noise. The noise of desktop computers is much louder than that of laptop computers. It is generally recommended that customers test the use of laptops to provide audio sources.

Amplifier gain description (required) : Thecomputer audio signal is very strong. Generally, the amplifier gain is 20DB, and each amplifier must be set to the minimum gain by the buyer. For weak audio signal input, only 36DB gain is used, which saves the cost of preamplifier circuit.
The gain of the power amplifier is also called input sensitivity. Set the gain to match the signal output of the host. Its function is to maximize the power output of the power amplifier when the output volume of the host is at its maximum. Do not use gain as a volume adjuster. If the gain is set improperly, if the setting is too large, the power amplifier will often have clipping distortion, or enter the protection state. If the setting is too small, the power amplifier is often unable to exert power. The key to setting the gain is to ensure that the maximum voltage or volume of the host is not true, and a senior technician can judge by listening.

Points for attention of the power amplifier board:
1. After the power supply of the power amplifier board, the DC voltage between the two pads of the speaker is 0V, and the DC voltage between the speaker pad and GND is half of the power supply voltage.
2. Choose a 4 ohm speaker, the maximum power supply voltage cannot exceed 16V, otherwise the chip will be too hot to damage the power amplifier. Choose 8 ohm speakers, the maximum power supply voltage cannot exceed 24V, otherwise the voltage is too high to breakdown the amplifier chip.
3. After the power amplifier board is powered on, your hands must not touch the component pins on the board, because the human body interference signal interferes with the timing of the digital power amplifier, resulting in damage to the chip and the human body with static electricity-strong high voltage will break down and damage the chip, the harm of human body static electricity Be sure to know.
4. The power supply voltage should be stable, try to use switching power supply and battery power. The power supply should not exceed the working voltage of the board, otherwise the chip will be burnt out, and the digital power amplifier is extremely delicate. It is not the same as the analog power amplifier, and the working method is completely different.
5. The speaker wiring should be controlled within 3 meters with the audio line as much as possible. The inductance of the load is too long and the self-inductance voltage is too high. The power amplifier chip is broken. It is recommended to consider adding a diode (IN5819) to the self-inductance voltage when the long line is connected to the speaker. Release protection chip.
6, 8 ohm speakers basically do not need to add heat sinks, less than 8 ohm speakers, if the chip temperature is higher than 60 degrees, because the work stops immediately, add heat sink fan heat, otherwise the temperature will immediately burn the chip.
7. The speaker power must be greater than 40W in order to test the amplifier normally, otherwise it will affect the normal operation of the amplifier. We used a 4W 300W stage speaker with 95dB sensitivity. The rated power of the speaker should be greater than the output power of the power amplifier. Otherwise, the power amplifier cannot work normally due to the speaker power is too small, the short circuit between the heating coils of the voice coil will damage the power amplifier.

Warm reminder: the
power amplifier board defaults to 36DB gain, and the computer input can only be turned on at a maximum of 20% volume, otherwise it will be damaged due to severe amplification and serious heat generation of the power amplifier chip, and the speaker will be damaged at the same time. Mobile phone input can turn on 90% volume, because the mobile phone audio signal is much weaker than the computer. To turn on the computer at 90% volume, the gain of the power amplifier board must be reduced, and the two 26DB gain pads on the board should be shorted. Once the input audio signal is too strong, the amplifier's amplification gain must be reduced, otherwise the amplifier will have amplification distortion and serious distortion amplification-exceeding the output power of the amplifier will damage the chip.

Common sense problem of electronic power supply: 24V voltage cannot be directly supplied to the power amplifier board, because 24V is directly supplied to the power amplifier board, the voltage is too high, the capacitor is short-circuited instantaneously, the current will be very large, plus the power amplifier 36DB gain, the capacitor instantaneous strong current mutation It will be damaged by the 36DB power amplifier, the power amplifier chip exceeds its own output power and breakdown and short circuit. The 24V voltage can only be started by switching the power supply to start the 220V voltage to buffer the 24V voltage, so as to restrain the instantaneous large current problem. (24V battery or lithium battery power supply, you can only connect a 1-2 ohm 5W resistor in series with the VCC pin to limit current, thereby reducing the problem of excessive current.)