Hi,
I currently have a TPA3255 amplifier board configured for 2 X 150watts @ 8 ohms, meaning it is configured for 2 channel BTL output. I would like to add either a watt meter (analog style) or VU meter (analog style) to indicate power output. Either will do, I could either do an 8 ohm reference and adjust the watt meter needle for 150W max, or could do a VU meter where the voltage output at 150W into 8 ohms would be indicated at approx the 0 db mark on the meter. I realize that I'm asking for one that measures wattage, and the other that measures voltage, but either choice would satisfy my requirements. Precise calibration is not necessary.
My question is given the lack of ground reference in the BTL output of the TPA3255, can somebody give me a reference, link to a schematic, or a possible solution that would allow an analog type meter to be connected to the output of this amplifier?
I have researched several VU driver boards, but all seem to be designed for a SE type amplifier output and I have been unsuccessful in finding a suitable solution for a BTL type amplifier output. Most VU driver boards have a 12VDC supply requirement, and they tie the power supply ground and the audio input grounds together, which would cause a short in the BTL outputs.
Any help or input would be greatly appreciated!
Thank you!
