Ultrasonic Fox Deterrent


A couple of years ago, I bought two of these fox deterrents for my front lawn but they stopped working during the winter. I’d assumed that there just wasn’t enough sun to keep the internal batteries charged but, when I took a closer look this week, I discovered they both have a manufacturing fault.

The solder joint on the positive wire from the solar panel had given way – in fact it had never been soldered properly at all. The wire was held in place by little more than hot-melt glue. The connection on the solar panel itself seems to have some sort of nickel-plating and refused all attempts to take solder to reconnect the wire properly.

Normally, connections to this type of metal are made using a cold welding process but the blob of solder on the wire showed the manufacturer had tried to use ordinary tin/lead or lead free solder

I was able to make a quick and dirty repair by cleaning off the hot-melt glue from around the connection and slipping a piece of thin metal between the top of the enclosure and the underside of the solar panel. I’ve hopefully held it in place with a blob of Araldite.

The third photo below shows one unit now charging away (as shown by the blue LED) and the second unit just waiting for the Araldite to harden before reassembling it.

You may also have spotted in the bottom photo that, although the exterior of the units give the impression they have two ultrasonic sounders, one is just a dummy and they do, in fact, only have one!