I am working on a magnetohydrodynamic boat project. The goal is to run a current of 5 amps through salt water. I bought an LM138 voltage regulator, configured it as a 5A current regulator by setting R1 at 0.24Ω. I have 24V on the input and the output is shorted directly to ground with a section of the output running through the salt water.
My problem is that the regulator is shorted, so its overheating. My next thought was then to add a high wattage resistor on the output as a load. But then if I am going to configure it that way, why have the regulator at all? My professor said to use an active circuit to avoid draining the battery. But it seems to me that whether I simply use a resistor between a battery and ground, an LM138 regulator, or a power mosfet circuit they all will be consuming 5A*24V = 120Watts, so what is the difference?
If anybody has some advice I would greatly appreciate it! Thanks!
JWK
My problem is that the regulator is shorted, so its overheating. My next thought was then to add a high wattage resistor on the output as a load. But then if I am going to configure it that way, why have the regulator at all? My professor said to use an active circuit to avoid draining the battery. But it seems to me that whether I simply use a resistor between a battery and ground, an LM138 regulator, or a power mosfet circuit they all will be consuming 5A*24V = 120Watts, so what is the difference?
If anybody has some advice I would greatly appreciate it! Thanks!
JWK
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