Hi,
I'm currently working on a model railway controller for my dad. I'm using 50VA transformer with a single 230V primary winding and two 15V secondary windings. I'm going to use one winding for the controller circuitry and use the second winding for a seperate AC outlet.
By my calculations, each winding will produce around 1.6amps @ 15v. So i'm going to use a 1.6amp circuit breaker on each secondary winding to protect that side of things. So my first question is - does that sound OK?
Where I get slightly confused is on the primary side. If the transformer is 230V and 50VA I think it should draw around 220mA. If i use a 250mA slow blow fuse will that be enough to protect it? I know about the surge that occurs when a transformer is first switched on, and I've been told to use a fuse twice the amp rating of the primary winding. But I thought that was why you use slow blow fuses - to cope with this surge but still protect the transformer properly. So should I use a 250mA, or a 500mA fuse?
Any advice on this would be great as I don't know too much about transformers at the moment.
Thanks,
John.
I'm currently working on a model railway controller for my dad. I'm using 50VA transformer with a single 230V primary winding and two 15V secondary windings. I'm going to use one winding for the controller circuitry and use the second winding for a seperate AC outlet.
By my calculations, each winding will produce around 1.6amps @ 15v. So i'm going to use a 1.6amp circuit breaker on each secondary winding to protect that side of things. So my first question is - does that sound OK?
Where I get slightly confused is on the primary side. If the transformer is 230V and 50VA I think it should draw around 220mA. If i use a 250mA slow blow fuse will that be enough to protect it? I know about the surge that occurs when a transformer is first switched on, and I've been told to use a fuse twice the amp rating of the primary winding. But I thought that was why you use slow blow fuses - to cope with this surge but still protect the transformer properly. So should I use a 250mA, or a 500mA fuse?
Any advice on this would be great as I don't know too much about transformers at the moment.
Thanks,
John.