I have a 220 V 50 VA to 2* 12 V 2.1 A transformer. If my calculations are correct, maximum input current for it should be around 227 mA. I want to protect the circuit which it is powering with a fuse. Unfortunately, when I power on the transformer, fuse pops (at that time, I was using 315 mA fast 5x20 fuses). After doing some research, I believe that fuses are dieing because of inrush current of the transformer.
I'm looking for a way to stop inrush current form popping the fuse (and slow fuses don't help, I tried), so the most obvious solution would be NTC thermistor. I found some 100Ω @ 25°C rated at 450 mW which look like they may be useful to me. Would they be a good choice or should I look for some with higher power rating? Also, from what I can see, they heat up and then their resistance drops. How hot would they be running? Also, I read in some documents that it's a good idea to serially connect several thermistors in order to increase performance. Should I do that? If yes, how much thermistors would be enough?
Another way which was recommended to me was to use chokes to control input current. It looks interesting to me because that way, I'd be able to avoid waiting for thermistors to cool down before powering the circuit again. Where would I start with them? I do understand that the choke will induce current which will oppose current coming in from power source, but I don't have much information on what inductances should I look for when getting a choke.
I'm looking for a way to stop inrush current form popping the fuse (and slow fuses don't help, I tried), so the most obvious solution would be NTC thermistor. I found some 100Ω @ 25°C rated at 450 mW which look like they may be useful to me. Would they be a good choice or should I look for some with higher power rating? Also, from what I can see, they heat up and then their resistance drops. How hot would they be running? Also, I read in some documents that it's a good idea to serially connect several thermistors in order to increase performance. Should I do that? If yes, how much thermistors would be enough?
Another way which was recommended to me was to use chokes to control input current. It looks interesting to me because that way, I'd be able to avoid waiting for thermistors to cool down before powering the circuit again. Where would I start with them? I do understand that the choke will induce current which will oppose current coming in from power source, but I don't have much information on what inductances should I look for when getting a choke.