# Making sense of it all

• Aug 18th 2013, 01:40 AM
fatherjack
Making sense of it all
33 ms = 33 x 10-3 s = 0.033 s
So, the duty cycle is (0.033 s ÷ T s) x 100% = 3%
(what is the value of T)

Transposing the formula gives T s = insert your workings here =

= Ans A s
= Ans B ms
1 hour = 60min x 60 s = 3 600 s

So, in 1 hour the node transmits,
3 600 s = Ans C times
Ans A s

Therefore, node transmits for

0.033 s x Ans C =

= Solution (3 s.f.) in every hour
• Aug 18th 2013, 08:27 PM
chiro
Re: Making sense of it all
Hey fatherjack.

Did you have a specific question in mind? Are you trying to understand a general concept better?
• Aug 19th 2013, 12:07 AM
fatherjack
Re: Making sense of it all
hi thanks for getting back to me
well a bit of both really, I want to work out the value of T?
• Aug 19th 2013, 12:16 AM
fatherjack
Re: Making sense of it all
20 ms in every 0 Calculate the duty cycle of a device that typically connects to a network and transmits for.5 s. You may wish to use a calculator for this activity.
20 ms = 20 × 10−3 s = 0.02 s
So the duty cycle is (0.02 ÷ 0.5) × 100% = 4%
This means that the device is operational for only 4% of the time. This is a example
--------------------------------------------------------------------------------------------------------------------------------------------

I need to work out the value of T

A typical sensor node has a transmit duty cycle of 3% and draws a current of 1.53 mA while it is in the active part of the duty cycle, and negligible current while in the inactive part of the duty cycle. On average, the node sends 375 bits of data per transmission and each transmission takes 33.0 ms.
i. How long does each node transmit for in every hour? Express your answer in seconds.

33 ms = 33 x 10-3 s = 0.033 s
So, the duty cycle is (0.033 s ÷ T s) x 100% = 3%
Transposing the formula gives T s =
= Ans A s
= Ans B ms
1 hour = 60min x 60 s = 3 600 s
So, in 1 hour the node transmits,
3 600 s = Ans C times
Ans A s

Therefore, node transmits for

0.033 s x Ans C =

= Solution (3 s.f.) in every hour