I had a 450mA 2s lipo powering the MP32 today while I was scoping, setting up, and testing the ppm encoder and a few various receivers (trying to find one which ones incorporate a failsafe in a way that would properly trip out the ppm encoder). During this time I noticed that the MP32 was making a noticable noise; like a low tone buzzing/hissing. I believe I powered down and removed the Oilpan and the noise went away. I noticed during this noise, that the scope was showing noise on the the ppm encoder sum signal - the width that changes corresponding to the channels value.
I removed the lipo and connected a larger battery 3s-2200 and the noise stopped.
I also notice that if you listen carefully, there is a sort of clicking that occurs when power is 1st applied to the MP32. Almost like a tiny relay.
Question 0:
What causes this hiss/buzzing noise? Is it dangerous to the MP32 or Oilpan when a connected battery gets too low?
Jim T
Replies
Hi Jim,
the DC:DC converter that i put on the board need minimum a 3s lipo , the operative range of DC:DC start from 8 volt , that is the reason because the rele start to doing noise .. Don't use the oilpan + mp32 with 2S lipo.
You can damage Oilpan Rele. Is possible to implement a safe logic on firmware for power off the rele if the voltage is under a value of 8 volt.
Best
Roberto