High amperage limiting

[awwende]

I'm working on a power supply to simulate the solar panels on a cube satellite at my university. The project is similar to Dave's power supply using a microcontroller in the power supply to limit the current based on the satellite's orbital path. The power supply will output 2.2V at about 9A of current. Does anyone know of an adjustable current limiting IC that can adjust 0-9A?

[amspire]

You can basically use a circuit just like Dave's. It is possible to parallel devices like the LT10180 or LM317 by adding a small resistor in series with each output, so you can get up to 9A that way. Better still, if you look at the LM317 data sheets, you will see circuits for the addition of a boost transistor to a single LM317 that would increase the output current to 9A.

Then for the current limit circuit, you just have to decrease the resistance value to 10 times lower then Dave's current sense resistor.

If you use a circuit that allows for the output voltage to go down to 0V out (with a LM317, this means having a negative supply so you can take the control pin down to -1.25V), then you could program a microcontroller to mimic the volt-amps characteristics of a particular solar panel.

Richard.

[qno]

The problem is the 2.2 volts.
LM317 designs wil not work.

You need Mosfet type of pass element but 2.2V is not enough to control the gate.

You can convert the voltage to 5 or 12 volts for your control circuit.

You can use a Hall sensor as current sensor.

[IanB]

will output 2.2V at about 9A

That seems like a very inconvenient power supply configuration. The high current at low voltage coupled with voltage drops and associated inefficiencies is going to result in a poor quality and inconvenient energy source.

Is there no option to reconfigure the solar panels to produce a higher voltage at lower current, for example 11 V at 1.8 A? I think this potentially would offer greater operating efficiencies and make it easier to deliver power at the point of need.