Automower 330x base station schematics

[Leif Neland]

The boundary wire for my Husqvarna 330x automover is 1200m long, so the
signal is too weak for the mower to properly follow the boundary in and
out.

Husqvarna does not have a signal booster for the 300 series, only the
200 series, neither do they have a secondary signal generator.

I want to boost the signal with an active amplifier, so a schematic
would be helpful.

This signal would feed a loop going around some areas inside the main
loop, which should not be mowed.

I've measured the signal with my dusty 'scope, and the signal seems to
be a digital signal, either 2v or 0v into a 20 ohm loop.

It is 50hz with some code appended to the trailing edge.

I could try to simply use an audio amplifier, but I guess it would be
better if I could replicate the base station.

So a schematic would be helpful.

Leif


--
Husk kￜrelys bagpￜ, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

[hri...@gmail.com]

Hi
My Automower 330x stopped working after a lightning storm august 2015. I delivered it to the supplier, who found that the power supply was defect. They also tested the base station and the robot on a small loop. That worked fine.

Back in my garden I connected all the cables (I have a boundary loop and two guides, about 5-600 m) and the base showed green light. The robot, on the other hand, reported "no loop signal". I tried connecting different wires to AL, AR, G1 and G2 and received a variation of blue and green lights. I have now tested the whole wire system with a 12V battery and a lamp, and all cables are intact.

I have also tested the robot on a small loop, where it works. On a large loop (with a new wire) it reports "no loop signal". Could the problem be that the signal from the base is weakend? Possibly from a nearby lightning strike?

Harald

[hell...@gmail.com]

Harald, I have exactly the same problem. Did you find any solution?

Anders

[hell...@gmail.com]

I found the "secret" menus on the robot, where you can the signal strength and quality.

With a small test loop, the values seemed reasonable, and the the quality was 100 (%?). With my large loop (that worked without problem before the thunderstorm) the signal is 0, and the quality is 0. That's weird - what is the problem, the loop itself, or the circuit board in the charging station?

You find the menus by pressing 0 for two seconds, and select "Info" and "loop".

Anders

[hell...@gmail.com]

My mower now works again! I had to change the board in the charging station.

/Ander

[eri...@gmail.com]

hi
i have a problem with my husqvarna 315, the LCD screen has the error No Loop signal and the light in the charger is strong green.

thanks

[bo.fo...@gmail.com]

According to the Husqvarna patent, the signal should be 40 Volt peak-to-peak, each group of pulses is repeated at approx 80 Hz, the leading pulse is 100 microseconds and the following data pulses are 50 microseconds. The output stage in the charging station is a push-pull stage driving the pulses 20 volts in one direction and then 20 volts in the opposite polarity, creating balances pulses at 40 volts peak-to-peak.
Acc to the patent the maximum pulse current is about 2 amps.
Then of course the patent is wide enough to accomodate similar solutions, so the values I have given are not necessarily those used in practice. However, because people can trace the signal with an old AM radio, the pulses would have quite a lot of overtones which indicate short pulses as described in the paten.
Unfortunately I have given away my old oscilloscope years ago, otherwise I would be lying in the grass analysing the signal....