I am developing my own PLC that is powered off a 24VAC transformer that is shared with a thermostat and some other controller devices. I wanted to isolate the 24VAC going into my PLC to protect it and I've been trying to find some small isolation transformers to attach to my PCB. I found a link off aliexpress for a cheap audio isolation transformer:
Can I use this to isolate the 24VAC? How can I derive the max amps and power loss from the values given by the seller?
Images attached:
- I am currently using a half wave rectifier
- I was going to configure the isolation transformer
- Here is what the audio isolation transformer on my PLC will look
Best Answer
Most likely not, signal transformers aren't designed to carry much current, the copper wires on them are pretty thin, hence they will burn if you pass even small amounts of current, on the other hand they may be able to carry higher currents but will have very low inductance (example: ethernet transformers) which will saturate the core if used with ac frequencies. In this case it would be the first situation, note that in aliexpress they don't specify the maximum operating current which is a key parameter for this application, so my recommendation would be to search for an adequate power transformer