Powered by Invision Power Board


Forum Rules Forum Rules (Please read before posting)
  Reply to this topicStart new topicStart Poll

> Low Power Rf Module Required, An RF Module required with low Current
port500
Posted: December 22, 2010 11:28 am
Reply to this postQuote Post


Newbie
*

Group: Members+
Posts: 4
Member No.: 34,114
Joined: December 22, 2010




Hello,

I am looking for an RF transceiver with very low current consumption. I am currently working on an RF based Automatic Meter Reading Project (AMR). We are looking for 433MHz Modules.

The modules that i have found so far have around 15-20mA Current consumption while transmitting. I am looking for a RF module with transmission current consumption less than 10mA. The required range is 100m.

My requirements are:
Frequence: 433MHz
I(transmitting) < 10mA
range>100m

I have no financial constraints in this regard. Any help will be greatly appreciated. Thank You

This post has been edited by port500 on December 22, 2010 11:44 am
PMEmail Poster
Top
kellys_eye
Posted: December 22, 2010 01:02 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 10,521
Member No.: 2,735
Joined: June 21, 2005




Power consumption will relate to radiated power and to attain a certain distance (with a given antenna) you will require a certain power - the efficiency of the transmitter will be high anyway so there's no particular way of improving it.

It therefore follows that you will require a more efficient antenna system rather than a low power transmitter.

Improvements in front-end design (at the receiver) might help permit a lowering of power at the transmitter too. Anyway, you could always lower the transmission times (once per hour?) to conserve power.

Is power conservation your main aim?


--------------------
May contain nuts
PMEmail PosterYahoo
Top
CWB
Posted: December 22, 2010 01:07 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 21,094
Member No.: 15,154
Joined: May 15, 2008




hmmm ...
if you need 100 meter range with 10mA of current draw you will need to find a module that uses a higher voltage than most of the others .
basically :
you need a given amount of rf power to "cover" the required range .
output power of the unit can be measured in watts (or milliwatts) .
(roughly , in this case) E X I = P (watts) .

what you will be doing is exchanging a higher voltage for lowered current consumption .
--- no free lunches ---

i take it that you have calculated what the tx/rx field requirements will be ?
without knowing this you will not be able to determine what the transmitter output power requirements would be .


--------------------
"Know how to solve every problem that has been solved"
R. Feynman '88
PM
Top
Ice-Tea
Posted: December 22, 2010 01:52 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 3,040
Member No.: 462
Joined: October 07, 2003




With lowest baud rate and lowest output power I guess you should get close to the minimum in this datasheet:

Linky.

Pretty damn sure you'll need a directional antenna to get 100m range for it, though.
PMEmail PosterUsers Website
Top
Ice-Tea
Posted: December 22, 2010 01:57 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 3,040
Member No.: 462
Joined: October 07, 2003




PMEmail PosterUsers Website
Top
Ice-Tea
Posted: December 22, 2010 02:30 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 3,040
Member No.: 462
Joined: October 07, 2003




PMEmail PosterUsers Website
Top
port500
Posted: December 23, 2010 05:26 am
Reply to this postQuote Post


Newbie
*

Group: Members+
Posts: 4
Member No.: 34,114
Joined: December 22, 2010




The Module will be integrated with Energy meters and used as an AMR system. The aim right now is to find an IC/Module that uses the least amount of Power/Current, and has a minimum range of 100m. The antenna design will come at a later stage. And the requirement from the power company is to transmit meter Data once every 20 minutes.
Tx needs to be below 10mA while transmitting at sufficient power to achieve a range of 100m in an urban area

This post has been edited by port500 on December 23, 2010 05:26 am
PMEmail Poster
Top
port500
Posted: December 23, 2010 05:49 am
Reply to this postQuote Post


Newbie
*

Group: Members+
Posts: 4
Member No.: 34,114
Joined: December 22, 2010




I already found the semtech SX1240 module, and so far it is the best solution. I am looking for something even more low power than it smile.gif
PMEmail Poster
Top
kellys_eye
Posted: December 23, 2010 12:57 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 10,521
Member No.: 2,735
Joined: June 21, 2005




Given it's to be integrated with energy meters, why the reluctance to draw the power from the actual supply being measured? It's not like it would be 'chargeable' (and even if it were, the customer couldn't complain).

I can't imagine for a moment that the device will be BATTERY POWERED huh.gif so why the emphasis on low power consumption?



--------------------
May contain nuts
PMEmail PosterYahoo
Top
Ice-Tea
Posted: December 23, 2010 02:31 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 3,040
Member No.: 462
Joined: October 07, 2003




Suggestion: supercap. Average the draw out over the inactive period.
PMEmail PosterUsers Website
Top
Village Idiot
Posted: December 23, 2010 09:13 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 1,556
Member No.: 11,398
Joined: October 08, 2007




Another option that no one has mentioned so far, to reduce transmitter current consumption and maintain 100m range, is to build a more sensitive receiver. A good quality low noise amp on the receiver front end is required.
PM
Top
port500
Posted: December 24, 2010 05:26 am
Reply to this postQuote Post


Newbie
*

Group: Members+
Posts: 4
Member No.: 34,114
Joined: December 22, 2010




We have decided to use the SX1240 and work on a better receiver design. Thank You for the feedback. Much Appreciated.
PMEmail Poster
Top
sherlock ohms
Posted: December 29, 2010 11:06 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 2,768
Member No.: 26,125
Joined: September 10, 2009




QUOTE (port500 @ December 24, 2010 03:26 pm)
We have decided to use the SX1240 and work on a better receiver design. Thank You for the feedback. Much Appreciated.


--------------------
"Quotation marks make sentences appear more meaningful."
PM
Top
CWB
Posted: December 29, 2010 03:50 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 21,094
Member No.: 15,154
Joined: May 15, 2008




some people have no shame at all ...
laugh.gif laugh.gif tongue.gif


--------------------
"Know how to solve every problem that has been solved"
R. Feynman '88
PM
Top
0 User(s) are reading this topic (0 Guests and 0 Anonymous Users)
0 Members:

Topic Options Reply to this topicStart new topicStart Poll

 


:: support us ::




ElectronicsSkin by DutchDork & The-Force