Hi, I am examining rovs from underwater robotic competition and I find out some of them using circuit breakers in electronics. Does it make sense to put circuit breaker on the vehicle? Or where to put these circuit breakers ?
Circuit breakers come in a wide range of ratings and trip delays. Some thermal ones could have a large voltage drop (3 volts).
I suggest a fuse to protect the wire and battery. You need to speak to someone familiar with fusing. It is not a simple subject.
I also suggest you run some tests on the fuses you intend to use. You may find a 1 amp (blade auto fuse from China, for example) takes many seconds to blow at 6 amps and will run forever at 4 amps. Stick to a reliable fuse from a company like Littlefuse, or buy from DigiKey.
I am using an 80 amp fuse at the battery and 20/30 amp fuses for the ESC. Using sockets I can easily change the value if necessary. I am using 3 vertical thrusters and two T200 horizontal in a custom design.
Make sure your test setup reproduces the ROV installation. The screws, wires, and connectors will dissipate heat and change the way the fuse blows. I don’t recommend this example of mounting a fuse because it is not protected from dangerous shorting.
I used a variac driving a 10 volt 200 amp transformer to get the required current to blow my fuses.
You can check your wire sizing as well, the black 12 AWG wire got quite hot compared to the red 10 AWG.
These ATO fuseholders can be soldered to a circuit board.
A possible power distribution scheme. Sw1 is the BlueRobotics waterproof switch. R1 holds the MOSFET switch off, R2 turns it on and is close to P4 to protect against shorting that would evaporate the wire to the switch. D1 shows power on and the other LEDs show a blown fuse. This is for troubleshooting and can only be seen if the tube is opened which is required for battery charging and is a good idea each dive to check for leaks.
If you want to place D1 in view from the front window then switch the position of D1 and R3 to protect against shorts. Avoid potential hundreds of amps shorting situations.
I have two circuit boards, one for the fuses and the other for the Solid State Switch (MOSFETS). The switch is on the negative side of the battery because it is safer there unless well insulated…
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