How do you calculate power consumption?

nicolad76

Hi,
I am working on my little project and the end result would be a portable device.
Each portable device requires a battery (unless you use it as paper weight....) so I was wondering...how do I calculate the total power consumption at design stage?
If I list all my components (all IC's) and I assume they would be all functioning for the entire use of the device (worst case scenario), is it enough to total up their power consumption? Should I add some % due to power loss and other components?

I know you experts have the answer [noparse]:)[/noparse]

Thanks
Nicola

Leon

That's what I've done when I've needed to estimate power consumption for a board. You need to include each output, of course, depending on the load it is driving.

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Leon Heller
Amateur radio callsign: G1HSM

Bobb Fwed

Adding all the components up will give you a broad idea of usage, but doesn't account for everything.

You could use an amp meter. You put them in series with your power supply and it tells you exactly how much power is being used. With a linear regulator powering your components you can just mark that down as your amperage. If you are using a switching regulator you will have to calculate the wattage because the amp usage is a product of the input voltage.

Instead of a amp meter, you could just put a resistor (1 or 10 ohm work good) in series with the power. Measure the voltage difference across the resistor and calculate the amperage.

I have a 30A, 2A, 500mA, 100mA, and 10mA meters on hand. It gives me the opportunity to find out exactly how much power my battery power projects use across a wide range of power usages. Most of the time I am just using the 500mA or 100mA meters though.

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String Manipulation Library - Don't allow strings to be the bane of the Propeller, bend them to your will!
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nicolad76

But you can do that when you have a prototype, right? I am still working on the project, to be honest, I do not even have the components yet [noparse]:)[/noparse]
I guess I will add them up and get an idea of what type of battery is needed, when I get the prototype done I will review this step.
Thanks a lot!