Electric Fence Active
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An electric fence that’s stopped pulsing is just a fence — and animals work that out fast. The OGLAS Electric Fence Active sensor confirms your fence is live, on a schedule you set, and raises the bell the moment it isn’t.
What it does
- Detects fence pulses — non-contact pickup (capacitive coupling to the fence wire), no high-voltage wiring into the device.
- Reports state periodically — default interval is 5 minutes; configurable.
- Reports immediately on state change — fence drops from active to inactive (or comes back), the device fires off a message right away rather than waiting for the next interval. This is the alert that matters.
- Tracks pulse rate — a healthy charger has a known cadence. Drift from the expected rate (broken wire shorting to ground, low-battery charger) shows up before the fence dies completely.
Common failure modes it catches
- Animal grounding — a sheep tangled in the wire pulls the fence voltage down. Pulses still happen but at much lower amplitude. Worth alerting.
- Broken wire — fence is “on” at the charger but doesn’t reach the far end. Catch this by deploying multiple Electric Fence sensors at known points along the line.
- Charger fault / dead battery — fence is silent. Most-common failure mode and the one that costs the most.
- Vegetation grow-in — gradually loading the fence; the pulse-rate trend will show it before it fails.
Hardware
Battery-powered sensor with a non-contact pickup. The pickup is a small antenna held a few centimetres from the live wire — induced voltage from each fence pulse triggers a counter inside the device. No galvanic connection to the fence, so no risk of energiser pulses entering the electronics.
- Power: Single LiPo with a small solar trickle. Designed to run a season per panel-side charge in average sunshine.
- Mounting: Sealed enclosure, magnetically or zip-tied to the fence post near the wire.
- Ultra-low deep-sleep current — battery life is the design constraint.
Multiple along a long fence
A single sensor at the energiser tells you the charger is working. Sensors at intermediate points along the fence tell you the line is working. For long boundaries, deploy two or three:
| Position | Catches |
|---|---|
| At the charger | Charger / battery faults |
| Quarter-way out | Breaks in the first half |
| Far end | Breaks anywhere on the line, line voltage drop |
Each one reports independently to the hub, with its own node name (fence-east, fence-far, etc.) so you know which segment failed.
Pairs well with
- Bell — fence drops, kitchen bell rings. The alert nobody on the property can ignore.
- Water Trough — the same family of “long-battery, GPS-pinned, alert-priority” sensors.
- LoRa Hub — logs the pulse-rate trend, raises threshold alerts.
Building this into a larger site? That’s exactly what we do — start a custom build or email us.