I've recently been using old induction motor run capacitors to limit AC current mainly because of how simple it is. Say I have a 24v 5 amp transformer and need to charge a 12 volt battery. Directly connecting it through a rectifier gives me a burned transformer. A switching current regulator is ~70% efficient and somewhat hard to build, but adding a couple capacitors between the transformer and rectifier is simple and works great.My question is how efficient are they? There's a large voltage drop yet they stay cool to the touch unlike a linear regulator, so I'm assuming they are as efficient or better than the switching regulator but I'd like to be sure.