Hi,
I have a question about my electronic project. I have two circuits: one is a bluetooth receiver based on BTM98 chip that works a 12V and the other is a Class D amplifier based on TDA3116 chip that works better at 19 V. If I connect both circuits to the same power supply, I hear a strange electronic noise from the speakers. The power supply uses switching technology and it is of low quality. However, if I use another power supply of high quality the behaviour is the same. This problem is solved in two cases: if I use a power supply of high quality and I provide energy from two different independent source channels and if I use two different power supplies, even if they are of low quality. It seems that there is a sort of electronic coupling between the two circuits. What do you suggest to do? I'm considering to buy a new power supply as the Huntkey HKA06519034-6J 19V 3.42A 65W. I need 1 A on 12 V and at least 3 A on 19 V.
Thank you
I have a question about my electronic project. I have two circuits: one is a bluetooth receiver based on BTM98 chip that works a 12V and the other is a Class D amplifier based on TDA3116 chip that works better at 19 V. If I connect both circuits to the same power supply, I hear a strange electronic noise from the speakers. The power supply uses switching technology and it is of low quality. However, if I use another power supply of high quality the behaviour is the same. This problem is solved in two cases: if I use a power supply of high quality and I provide energy from two different independent source channels and if I use two different power supplies, even if they are of low quality. It seems that there is a sort of electronic coupling between the two circuits. What do you suggest to do? I'm considering to buy a new power supply as the Huntkey HKA06519034-6J 19V 3.42A 65W. I need 1 A on 12 V and at least 3 A on 19 V.
Thank you
Have you tried earthing the zero volt line ?
I use an mp3 player with its own power supply and an amp with its own power supply.
If I don't earth the common zero volt line I get lots of hum.
I use an mp3 player with its own power supply and an amp with its own power supply.
If I don't earth the common zero volt line I get lots of hum.
Place a 4.7-10R resistor and a low ESR cap in the BT power line. (RC-Filter)
This fixed most of the noise problems here with BT modules in different implementations.
ESR is the key factor here as it dominates the maximum achievable attenuation. 800-1000uF and some 10-30mR is a good rule of thumb.
This fixed most of the noise problems here with BT modules in different implementations.
ESR is the key factor here as it dominates the maximum achievable attenuation. 800-1000uF and some 10-30mR is a good rule of thumb.
I just tried to connect the zero voltage line (zero voltage ground) to earth. This did not changed the presence of noise.
Moreover, I put a RC filter directly between the power source and the BT power line. The filter was made of capacitor with low ESR of 940 uF and a resistor of 10 Ohm. So the cut-off frequency is approximately f_c=1/(2 pi R C) = 17 Hz. Unfortunately, even this did not change the presence of noise.
Of course, if I disconnect the BT module the noise disappears. It seems something of high frequency than DC component.
In attached you can find a sound file with the noise. The variation of noise signal is directly connect to the blinking LED of BT board.
https://mega.nz/#!QhsiBTSB!nF6PYilH6IQZPvXdk5BsRs-HuElkUQnSVyC55ZSnVes
Thank you
Moreover, I put a RC filter directly between the power source and the BT power line. The filter was made of capacitor with low ESR of 940 uF and a resistor of 10 Ohm. So the cut-off frequency is approximately f_c=1/(2 pi R C) = 17 Hz. Unfortunately, even this did not change the presence of noise.
Of course, if I disconnect the BT module the noise disappears. It seems something of high frequency than DC component.
In attached you can find a sound file with the noise. The variation of noise signal is directly connect to the blinking LED of BT board.
https://mega.nz/#!QhsiBTSB!nF6PYilH6IQZPvXdk5BsRs-HuElkUQnSVyC55ZSnVes
Thank you
After moving my BT setup to the other end of the living room, I began picking up relay noise when the forced air heater fan kicked in and when the BT on the BT tablet was turned off the spikes stopped.
My BT receiver had been placed right above the area of the basement where the heater is located so the emf was being picked up by the BT. The interference was not in the mains circuit because I have a tda7297 that never gets turned off and runs super quiet.
I have managed to fix the problem by putting a piece of sheet aluminum under the BT receiver which blocks the interference from below.
Have you tried turning off your WiFi? Apparently they can interfere with each other
My BT receiver had been placed right above the area of the basement where the heater is located so the emf was being picked up by the BT. The interference was not in the mains circuit because I have a tda7297 that never gets turned off and runs super quiet.
I have managed to fix the problem by putting a piece of sheet aluminum under the BT receiver which blocks the interference from below.
Have you tried turning off your WiFi? Apparently they can interfere with each other
Hi,
thank you for your reply. I do not have any WiFi turned on. I changed my amplifier board with a TA2024 amplifier. I used one power source at 12 V for both BT board and amplifier board and the noise is disappeared. So it seems a strange interaction between BT board and TDA3116 amplifier board. Now I will buy a new TDA3116 of different manifactur.
thank you for your reply. I do not have any WiFi turned on. I changed my amplifier board with a TA2024 amplifier. I used one power source at 12 V for both BT board and amplifier board and the noise is disappeared. So it seems a strange interaction between BT board and TDA3116 amplifier board. Now I will buy a new TDA3116 of different manifactur.
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