Cumulus Support

Hi Guys, I am experiencing some problems with my WH1081 that I recently installed about a month ago. I fitted brand new batteries to both transmitter and receiver whoever now i am not getting any outside data (wind, temp, humidity etc). I have noticed on the receiver display the following flashing icon.



My guess is that the batteries in the transmitter are low and needs replacement. I have looked the limited manual that I have but do not see any mention of this flashing icon.

Any help would be greatly appreciated as the weather station is atop a 6 meter tower.

Murray

I would suggest that a 6m climb is in order, it looks like your transmitter batteries are stuffed

Hi,

What type of batteries did you use? However a month is far too short a time for almost any type of battery to have failed. General wisdom is that Alkalines are suitable for most locations (and even the cheap "Heavy Duty" type should run the transmitter for a year), but the expensive Lithium AAs (1.5 volt type) are better, particularly in low temperatures (below -20 degrees C).

Please could you look at all of this thread as your observations might be able to add to the general knowledge base.

Thanks, Alan.

Thank you guys.

I think I will tinker with a couple of small solar garden lights and butcher them in such a way as to charge some rechargeable batteries in the transmitter unit, anyone done this, I'll have a trawl through the forum and have a look.

Murray

Hi Murray,

Yes there is a thread which I am planning to add to soon, because I've been doing some tests to achieve much the same.

However, I think you should attempt to discover why the first batteries appeared to die so quickly. If you're considering modifying some garden lights you may be sufficiently proficient to do a simple test on the transmitter power consumption. Do you have a multimeter? However, the main components you would need are a resistor of about 10k and an electrolytic capacitor of a few thousand microfarads (quite large, but only a low voltage is required). I'll explain how if you're interested.

Cheers, Alan.

Hi Alan, yes I have every thing on your list and would love to hear what ever advise you have to give.

Hi Murray,

I haven't seen anybody quote the power consumption (current) of the transmitter, but most users seem to achieve at least a year's operation, sometimes with quite basic batteries. The currents I quote here are only for my own unit, so it will be interesting to see if anyone agrees (or disagrees) with them.

The average power (or current) consumption is not easy to measure because the unit draws two relatively large, but short, pulses of current over the 48 second period of each transmission cycle. The continuous current seems to be negligible except for about 25 uA (microamps) when the reed switch in the windspeed unit is closed (and of course plugged in). The transmitter draws a pulse of perhaps 20mA when actually transmitting, but this lasts only 48ms (i.e. 0.1% duty cycle) so averages only 20uA. Four seconds before the transmission the A/D converter uses 1mA for about 1 second, so another average of about 20uA. This last figure depends on the wind vane direction, but unintuitively consumes more current if the wind vane is unplugged (because the A/D converter runs for longer).

So my estimation is that the (or my) transmitter has an average current consumption of about 50uA. This suggests that the transmitter might work for many years on a set of good batteries. You might get some indication from your multimeter if your transmitter is drawing very different currents, but my proposed test method is as follows:

Use a pair of fresh AA alkaline or "heavy duty" batteries. Tape two short (a few inches) lengths of insulated wire (with stripped ends), onto the positive end of one battery and the negative end of the other, so that when inserted the cells will contact the wires and NOT the transmitter's contacts. Connect an electrolytic capacitor of at least 2,000uF to the two free wire ends (positive to positive) and a third temporary (short circuit) wire (which can easily be removed, ideally a croc clip test lead) across the capacitor.

Insert the batteries into the transmitter so that the insulated wires are at the lower (common, shorted) contacts. The transmitter LED should turn on for a few seconds as usual. Optionally, remove and re-insert the receiver batteries if you wish to synchronise it to receive/verify the transmissions.

If you want to use a meter, connect this and a resistor of perhaps 10k ohms across the capacitor in place of the shorting link, either measuring the voltage across or (perhaps better) the current through the resistor. Wait for a few minutes and then estimate the average current/voltage through/across the resistor over a 48 second cycle. See if it is consistent with my figures quoted above.

Or, without using a multimeter or resistor, wait for the transmitter LED to flash and then remove the wire link across the capacitor. Watch the LED for a few minutes and count how many times it flashes (before the voltage across the capacitor prevents any more transmissions). If the receiver is synchronised, this should also confirm the time when contact is lost*. I would expect a capacitor of a few thousand microfarads to support at least one or two transmissions (LED flashes).

*ADDENDUM: Note that the console does not seem to report "lost contact" until 6 - 8 consecutive transmitted messages are not received. So you need to have a continually chaging value (e.g. wind direction or simulated rain tips) to check whether data is being received every 48 seconds.

Cheers, Alan.