Second Pass Results for Mag Switch + BEC

A project log for Magnetic Switches for RC Aircraft

Four versions of a simple on/off power switch activated by a magnet.

bud-bennettBud Bennett 04/24/2018 at 20:530 Comments

The second pass modifications were only to improve the input transient response to prevent catastrophic failure when connecting 4S (16.8V) batteries. Here's the scope trace of the input transient from a Multistar 3S battery (with a 25mΩ resistance):

This was a HUGE improvement from the first pass:

It appears that the input transient problem is solved. The only downside is the additional power dissipation from the 75mΩ input resistor.

All of the other parameters that I measured were consistent with first pass results, as expected. There  won't be a third pass. I still need to evaluate the circuit using a 6A switcher IC, but that is pretty low priority.