I'm not much of an electrical engineer, but I love to tinker. My current main hobby is building and flying drones.
I recently bought a cheap power distribution board that has built in voltage regulators and OSD (on screen display) for FPV (first person view). I power the system with a 4S LiPo battery (14.8v nominal). The PDB has regulators to provide separate 5v and 12v output. My video transmitter and FPV camera are powered off the same 12v output.
Being a cheap board and probably having some design flaws, there is a common problem with the video cutting out as the motors and ESCs increase their power draw. A video was recently posted showing a couple of capacitors being used to resolve the problem. A 6.3v 1000uf on the 5v rail, and a 16v 470uf on the 12v rail. No explanation for why these specific capacitors were chosen is given. Video here: https://www.youtube.com/watch?v=VCb7Gu6ty3o
I understand the capacitors voltage rating should be higher than necessary. But in a case like this, how do you determine how much capacitance is needed? This isn't a case of replacing a capacitor so having the old one to go by, but adding one where there wasn't one before. Would lower uf rated capacitors work in this case? How would I determine that (besides using them and seeing what happens)? There must be a way to calculate the minimum required uf rating.
Also, in this video, his camera is powered by the 5v, and his video transmitter on the 12v. As I mentioned, both of mine are on 12v. In my case, would I even need to add a cap to the 5v? The board's OSD system uses 5v and some people report solid video but OSD cutting out at higher throttle levels. Would a cap on the 5v system help with that even though my camera and vtx are on 12v?
I recently bought a cheap power distribution board that has built in voltage regulators and OSD (on screen display) for FPV (first person view). I power the system with a 4S LiPo battery (14.8v nominal). The PDB has regulators to provide separate 5v and 12v output. My video transmitter and FPV camera are powered off the same 12v output.
Being a cheap board and probably having some design flaws, there is a common problem with the video cutting out as the motors and ESCs increase their power draw. A video was recently posted showing a couple of capacitors being used to resolve the problem. A 6.3v 1000uf on the 5v rail, and a 16v 470uf on the 12v rail. No explanation for why these specific capacitors were chosen is given. Video here: https://www.youtube.com/watch?v=VCb7Gu6ty3o
I understand the capacitors voltage rating should be higher than necessary. But in a case like this, how do you determine how much capacitance is needed? This isn't a case of replacing a capacitor so having the old one to go by, but adding one where there wasn't one before. Would lower uf rated capacitors work in this case? How would I determine that (besides using them and seeing what happens)? There must be a way to calculate the minimum required uf rating.
Also, in this video, his camera is powered by the 5v, and his video transmitter on the 12v. As I mentioned, both of mine are on 12v. In my case, would I even need to add a cap to the 5v? The board's OSD system uses 5v and some people report solid video but OSD cutting out at higher throttle levels. Would a cap on the 5v system help with that even though my camera and vtx are on 12v?