Hello All,
I am using a supercap as a backup battery to power a computer when the power fails. The circuit only has to run for about 10 seconds before the power fails all together.
Now i know the computer consumes about 1.5A when running and it can have a voltage range of 9V to 12V. However if i connect my computer to a fully charged supercap as the capacitor dicharges the voltage falls exponentially. Therefore i would also expect the current to follow the same curve.
I was considering using a constant current circuit to keep the current at 1.5A over the voltage range from 12V to 9V then disconnect the PC from the cap. I have no idea if this will work. The entire circuit will be ran off the capacitor voltage. Therefore the opamp in my constant current source will have its +ve rail tied to the capacitor output and will fall at the same rate. It wont be stable.
Does anyone have any circuit ideas for this and would it work?
Thanks
I am using a supercap as a backup battery to power a computer when the power fails. The circuit only has to run for about 10 seconds before the power fails all together.
Now i know the computer consumes about 1.5A when running and it can have a voltage range of 9V to 12V. However if i connect my computer to a fully charged supercap as the capacitor dicharges the voltage falls exponentially. Therefore i would also expect the current to follow the same curve.
I was considering using a constant current circuit to keep the current at 1.5A over the voltage range from 12V to 9V then disconnect the PC from the cap. I have no idea if this will work. The entire circuit will be ran off the capacitor voltage. Therefore the opamp in my constant current source will have its +ve rail tied to the capacitor output and will fall at the same rate. It wont be stable.
Does anyone have any circuit ideas for this and would it work?
Thanks