I've been trying to learn how to properly set up a circuit for power regulation. Often I hear for domestic use that it is better to use a transformer to isolate the device as well as stepping down the powerline voltage (230V RMS here). Seems pretty straight forward for lower voltages, but what about a heating element which is supposed to be supplied with 230V RMS? Is a 1:1 transformer still needed? If yes, is a 1:1 transformer and a LR8 regulator enough (obviously with some more passive elements and diodes) to generate a 5V (for a µcontroller for example), or will I need a second transformer?
If useful, the point is that my project will need 3 voltages: AC Line (heating element), about 15VDC (Peltier element), and 3.3/5VDC (µController, gates, fans, etc.).
The heating element is something like this.