Full Member level 5
Hi. I've been interested in audio amplifiers for a while and I've began thinking of how much I can actually get out of a linear transformer? Giving that music is extremely dynamic and that the maximum power peaks are often several times greater than average power, couldn't it be an idea to install some sort of automatic fuse just to make sure the long-term average isn't too high? This particular transformer I have in front of me now is +/-18V 50VA with insulation class B which means that It can handle a temperature up to 130C (if I've understood it correctly). What if I attached a thermistor to it and made it so that the output cuts out when the transformer reaches 110-120C? I would still have a regular slow-blow fuse rated slightly above the transformer rating, but would attaching such a thermistor be ok engineering practice? Another thought is to monitor the supply voltage with an ADC, store the highest and lowest measured values to calculate the total supply ripple. By knowing the capacitance of the supply, total current consumption is directly related to supply ripple so the MCU can figure out how much current is drawing. It would then have to do some long term averaging to figure out if it needs to cut the output or not. I just imagine that a lot higher perceived output wattage can be reached by still having a rather small transformer with techniques like these, but I'm not sure if they are considered good engineering practice? I assume that a melting transformer is not a pretty sight?