# Wifi Transmission; Energy involved in sending a Wifi Signal

Discussion in 'Radio and Wireless' started by akahn430, Oct 29, 2016.

1. ### akahn430

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Oct 29, 2016
I'm currently working on a project involving Wifi transmission. The device needs to send a 1-3 digit number to a computer/phone that is 5-15 feet away. Approximately how much energy will this take to send one number?

Thank you!

Austin

2. ### davennModerator

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1,941
Sep 5, 2009

hi Austin
welcome to EP

a very odd question
A wifi connection is maintained, once a connection is established with or without data being transmitted
There is continuous background link etc checking going on

do you really need wifi ? Bluetooth would probably be easier

so would you like to tell us what you really mean

Wifi and BT are low transmitter power devices, they will have a minimum power out of maybe around 10 - 20 mW

Dave

3. ### akahn430

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Oct 29, 2016
Hi Dave. Thanks for the response.

Depending on the range that is needed, I suppose it could use Bluetooth.

What I am trying to get at is: I need to make a system that calculates force in an object when struck (Accelerometer), then sends that force back to a Computer/phone... and it has to power itself, so first, I need to figure out how much energy needs to be generated for each time the Force (1-3 digit number) is sent to the computer, for the system to function.

4. ### davennModerator

13,801
1,941
Sep 5, 2009
BT is good for up to 10m

Power needed in the way u are asking is irrelevent as i said earlier there is going to be continuous power usage. Not just when u send data

5. ### akahn430

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Oct 29, 2016
Thanks again for the response.

So there would need to be a constant voltage? How would I go about figuring out how much energy has to be generated to power the constant voltage?

6. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,482
2,830
Jan 21, 2010
You multiply:
1. the voltage (required by the transmitter and produced by the power source)
2. by the current (drawn by the transmitter)
3. by the time (that you want the transmitter operating -- could be minutes, hours, or days)
That gives you an amount of energy required.

From that you can choose an appropriate battery.

7. ### akahn430

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Oct 29, 2016
Ah, makes much more sense now. I really appreciate the help!