rclark43:
Perry,
I have a White-rodgers Class 2 Transformer, 40 VA Rating step down transformer (120V AC to 24V AC). Not sure how to verify it is mains isolated without taking it apart first.
"Please PLEASE! If you have to ask that then you do not know enough about electricity to be doing this. Please stop."
-I get it, that's why I'm trying to learn; I haven't even tried wiring anything together. That's why I'm asking for help so I can gradually get a better understanding. At some point we all didn't know and had others help us along the way. That said, is +ve and -ve the hot and neutral AC (which would switch directions and signs), or is it the positive and negative side of the DC after the bridge rectifier?
I know I'm new to this but I have to start somewhere; it would be more helpful to tell me what to do or what not to do, instead of telling me to stop. I am here to learn and understand the dangers inside out instead of giving up.
I cannot say that any specific transformer is safe for any particular application, only the manufacturer can tell you that. Even then, they will say the end application affects the safety. Having said that, reducing to 24V makes it a lot safer. Please remember where this discussion started, it started with you saying:
I'm interested in taking 120V AC and running it through a full bridge rectifier to try and get DC current
Which terrified me as doing so provides no isolation from the mains and is dangerous. Now you have mentioned a transformer I am a bit more relaxed.
My warnings might be a bit over the top but I am concerned not only for your safety but also for the safety of anyone else reading this who also doesn't understand the risks.
That said, is +ve and -ve the hot and neutral AC (which would switch directions and signs), or is it the positive and negative side of the DC after the bridge rectifier?
I'll try and explain again. The mains supply is AC, as I think you know. The 'hot' (as you call it, I'm guessing that is US terminology, we call it live) side swings between (for 120V supply) between +170V and -170V (about +320V and -320V in the UK and European countries), the neutral side is the same as or close to the ground. By ground I mean the environment including the muddy stuff under your feet. This is not the same as the +ve and -ve coming out of the rectifier in your diagram because the rectifier switches the incoming AC to the correct +ve and -ve output terminal of the rectifier, so, when the mains hot (live) wire is positive it it is connected to the +ve terminal of the output of the rectifier, when the hot (live) wire is negative it is connected to the -ve terminal of the rectifier. Thus neither the +ve or the -ve terminal of the rectifier can be considered to be at ground potential, both of them are at mains live potential for half the time, both of them are just as dangerous as the incoming mains. I hope that makes sense.
I know I'm new to this but I have to start somewhere; it would be more helpful to tell me what to do or what not to do, instead of telling me to stop. I am here to learn and understand the dangers inside out instead of giving up.
I appreciate that, but the way to start understanding is to start with voltages that won't kill you if you touch them, voltages below 50V. Once you understand those then you will have an understanding of what makes mains dangerous. You are trying to drive a racing car without an instructor sitting next you when you are yet to learn to ride a bike. Stick to the safe voltages from commercially produced power supplies.