This is work in progress, a solar powered, bright permanent red light when fence is faulty or off. Note that there is no earth connection. The small inductance acts as an air dump, it is 15 turns of insulated wire on an air core of 10mm diameter. The earth and 10MOhm is only shown so that the circuit works in EveryCircuit. Powered by a single 3.7V LI Ion cell and two 5V solar panels, fitted either side so the sun is always powering it. All fitted into a plastic box 75mm x 25mm x 35mm and hangs directly on the fence. The potentiometer adjusts the fault voltage setting.
Tried it today, works well. LED is LED-UB10 from Bright Components, very directional, recommend.
