What kind of bed is that? Try using a multimeter to check its resistance. Only after that you can figure out how much current it will draw when supplied with 12v. For example if it has 0.9 ohms, it will draw 12v/0.9ohms = 13.33amps. If it draws less than 10amps, you should be safe. But anyway, where did u read the ramps cant handle the bed current. First find out exactly how much current your bed wants, and then you can figure what to do.
The load (bed) is supplied hardwired with 12v. The mosfet switches its ground, hence this setup is called "low-side switching".
The mosfet has 3 terminals:
- one is named Gate, and this one is connected to the uC pin;
- other terminal is Drain, and this connects to the gnd side of the bed;
- the last is named Source and this one is connected to psu gnd.
When the uC outputs 5v on the gate pin, the mosfet will conduct current from drain to source. Meaning it will connect the bed gnd side to the psu gnd so the current will flow through the bed. Other than that, the bed is always connected to +12v, but if the gnd is disconnected the current cant flow anywhere. So its only the gnd that switches.
The load (bed) is supplied hardwired with 12v. The mosfet switches its ground, hence this setup is called "low-side switching".
The mosfet has 3 terminals:
- one is named Gate, and this one is connected to the uC pin;
- other terminal is Drain, and this connects to the gnd side of the bed;
- the last is named Source and this one is connected to psu gnd.
When the uC outputs 5v on the gate pin, the mosfet will conduct current from drain to source. Meaning it will connect the bed gnd side to the psu gnd so the current will flow through the bed. Other than that, the bed is always connected to +12v, but if the gnd is disconnected the current cant flow anywhere. So its only the gnd that switches.