[werk_ag]

I'm gonna describe a small trick that will decrease the power consumption of a TX board, avoiding the power loss in the 7809 linear voltage regulator... additionally with care, you can also increase radio signal range.

This trick will cost less than $1.

- If you have the 7809 already installed, remove it.
- On the TX board, do a shunt between input and output pins of the 7809 regulator.
- Buy on eBay or wherever you which a step down converter module like this ine below. They cost less than $1



- Connect your power source to the module input, and adjust voltage output to 9V.
- Connect the output of the module, to TX power in.
- If you are using +Bat pin to monitor the battery voltage in a solar system, just keep it connected to positive (+) battery terminal.

How just doing this will increase my radio signal range? Just doing this don't do it!
But... if you carefully adjust the voltage output of the step down converter to up to 10V, the radio signal range will be slightly improved.
Vendors claim that the RF power transistor can be powered up to 12V. According to my experience with the RF modules used in the WeatherDuino TX, don't go further than 10V.

And that's all. Less power consumption and a few more meters in RF signal range.

[tyntop]

Hi,

Does this trick work on all TX board versions and can you post diagrams/ pictures of how it is done.

regards

tyntop

[Shred]

Thanks for sharing this modification. Have you actually measured the current used by the modified TX board? (You knew someone would ask, didn't you!).

I've been tempted to use one of the Traco Power switching regulators. They are not cheap at around AU$ 10.00 each, but they're a drop-in, high efficiency replacement for the 78xx regulators.

http://au.rs-online.com/web/p/switching-...s/8179413/

[werk_ag]

Hi,

Does this trick work on all TX board versions and can you post diagrams/ pictures of how it is done

Yes, works with all versions.
Sorry I haven't any pics or diagrams. Please read carefully the post above, I'm sure you'll figure how to do it.

I've been tempted to use one of the Traco Power switching regulators. They are not cheap at around AU$ 10.00 each, but they're a drop-in, high efficiency replacement for the 78xx regulators.

http://au.rs-online.com/web/p/switching-...s/8179413/

The result is exactly the same, but this way you spend less than $1, and additionally you gain the possibility to raise a little the output voltage and boost the RF range.

The gain in consumption depends mainly of two factors:
Input voltage in the 7809 (generically 12V but with solar systems can reach 13.8V or more)
System with or without a fan for the radiation shield.

For a system without a fan, powered by 12V the power saving is around 0.2W, but for systems with a fan, it can reach 0.5W

[Palmyweather]

Does this trick work on all TX board versions and can you post diagrams/ pictures of how it is done.
tyntop

I have just made this modification to my system and have taken some photos to hopefully help out. The modifications are very simple but you will need a multimeter or similar to make sure you get the right voltage out of the DC-DC Voltage Converter.

               

I have left my unit modular (with a plug on the end) so that I can easily disconnect the TX board from all the sensors to program when required. But this is personal choice, you could simply solder the voltage converter directly to the TX board.

I also wrapped the whole voltage converter module in insulation tape before installing it as I wanted to make sure that nothing would move and cause a short anywhere on the board as that would end badly.