Simple power question - I hope

I’m new to the arduino, I’m using it to create a vacuum pump for prosthetics and need to power the arduino and a 7.4 V vacuum pump. How do I reduce the power to the Bluetooth arduino and maintain the 7.4V from the Li-polymer battery for the pump.

Thanks in advance
Craig.

It sounds like you need a voltage regulator.

Try to google voltage regulator, and i think you will find the answe to your need

Remenber that a Voltage regulator needs an input of at least 2 Volts more than it’s rated output.

EDIT: Can’t the Arduino BT be powered with 7.4 Volts ? Check that out first :slight_smile:

EDIT: Can’t the Arduino BT be powered with 7.4 Volts ? Check that out first :slight_smile:

No - 5.5V max.

Mike

Thanks for the info!

Craig.

cheap hack:
try five AA, C or D size batteries in series: the first three will give you 4.5V for the BT, and all five give you 7.5V for the pump.

------i|-----------i|-----------i|-----------i|-----------i|-----
GND + + + 4.5V + + 7.5V

Remenber that a Voltage regulator needs an input of at least 2 Volts more than it’s rated output.

Just to be pedantic, the exact “voltage drop” depends on the model of regulator, but for a standard 78XX voltage regulator (e.g. 7805) it is indeed 2V.

–Phil.

P.S. (Yeah, I’m a bit late in replying–catching up on my forum reading. :slight_smile: )