Hi team,
1. The schematic is as follows, with R9, R18 changing to 75kΩ, R10, R19 is changed to 47kΩ, which means the gain is changed from 26dB to 36dB.
2. The Layout is as follows:
3. The power supply uses DC24V/5A.
When the sound is turned to the maximum, the following problems occur after a period of operation:
A. One product goes to maximum volume and after a few minutes, the two outputs of one of the TPA3116D2 outputs become less strong. Use multimeter AC to measure voltage at both ends of horn, normal operating horn is around 6V at both ends and low strength horn is only around 3V at both ends. Also, the TPA3116D2 output, which is getting low, remains low until power is removed and then reapplied. The heat sink temperature on the normal output TPA3116D2 is approximately 120°C and the heat sink temperature on the lowered TPA3116D2 is approximately 80°C.
B. One product, operating for a period of time (approximately 10 minutes), the two TPA3116D2 IC outputs alternately become low and high.
Could you help check this case? Thanks.
Best Regards,
Cherry
