| Electronics > Beginners |
| Mosfet output protections - outdoor applications |
| (1/1) |
| Tantalum:
Hello I wanted to build a 24V DC + 1-Wire network for outdoor applications. The wires could be quiet long, like 30m. I'm planning to use a PCB with MOSFET on it to drive on and off the different channels (actually I'm using TPS2482 efuses). Now the question I have is about the DC protections I needed to add on the output of the mosfets. In case of lightning I could imagine that there could be huge amount of overvoltage induced in those cables. If I add GDT/MOV/TVS on the output of the mosfet I think it would be ok in the case of the mosfet is on. The overvoltage passes to the ground line and it would be at max be at the same potential as the V+ (which is connected through the mosfet to the circuit). Now, if the output of the mosfet is switched off, the same will happen, but because the V+ isn't connected to the circuit anymore (mosfet off), the ground could be at a higher potential as the V+ (PCB side). In other words the components will probably burn. I'm wrong? How should I protect the output of the mosfets??? Thank you |
| T3sl4co1l:
Just stick on a TVS (say SMAJxxA size), to protect against overvoltage. Lightning induced surge over that length shouldn't be a big deal, assuming there isn't a ground reference at the far end that is. Tim |
| Navigation |
| Message Index |