I just used a hi power mosfet (200amp) to do the switching. Im going to interupt the negative leg of the circuit as i do on my vape projects.
Ill now put it on a permanent board! By the way my very first circuit ive ever done on a borard!!!
@faja66 just a quick warning that the wiring in these photos doesn’t seem adequate or safe for the kind of voltage or current you’ll need to weld something.
I don’t know you yet, but I’ve been doing your amazing kits and what not. I
did test it, and it does work. Somehow I burned out the mossfet. It was
rated at 200amps
Your friendly neighborhood service tech. David Black.
I think what Tom is getting at is that at 200A, you will be exceeding the ampacity rating for the wire. This is usually given on a table (Wikipedia’s works well)[American wire gauge - Wikipedia]. The conductor in the wire will heat up and melt the insulating sheath,and probably the conductor itself. This is why car jumper cables are so thick, they pass current in the ranges you are looking at.
It also doesn’t look like you have a flyback diode on the mosfet. Maybe it is included in the package, but if not then you will need something to dissipate the inductive spike which happens when you switch off the current. This will for sure kill the mosfet. It will also generate dangerously high transient voltages which could cause sparking and or electrocution. Transient behaviour is important to look at in high power circuit design.
You could try modeling your circuit on Circuit Simulator Applet to get a better idea how it will behave. Just remember that wires are actually circuit elements (ie, resistors) too at high current.
a few pics i don’t have in the mix. Im using 2 10g booster cables doubled up. Ive since tore it apart and am going to run 2 mosfets in series. Anyone have any sugestions what type i should use?
