Faraday Defense makes the point that most people would have no idea an electromagnetic pulse had happened. A high-altitude detonation is too high to see or hear, and a solar storm gives warning of its arrival but not of what it will do to the power lines. The first sign would be electronics that have stopped working. The three DEFCON detectors exist to change that: a wearable tag, a plug-in alarm and a breaker switch that acts on its own. This guide explains what each one detects, what it does when it does, and how they pair with the T.R.A.P. and DEFCON vehicle kits.
E1, E2 and E3: what the detectors are listening for
Faraday Defense describes an EMP in three parts. E1 and E2 are the very fast pulses, on the order of nanoseconds, that couple high voltage into cables and wiring. E3 is the slow, sustained part that drives large currents around the power grid, the part that damages transformers and the part a solar coronal mass ejection (CME) resembles. The distinction matters here because the detectors differ on exactly this point: the Pulse Tag hears E1 and E2 only, while the EMP Alert and the Home Switch also watch the power line for E3.
DEFCON Pulse Tag: the wearable
The DEFCON Pulse Tag is a compact detector that clips to a pack, a coat or a piece of equipment with two removable hook-and-loop straps, one with an HK clip and one with a key ring. Faraday Defense rates it to sound an audible alarm within 100 milliseconds of the E1 and E2 pulses of a nuclear or military EMP, monitoring pulse durations around 20 nanoseconds. A reset button silences the alarm once you have acted. It lives in a shockproof, water-resistant thermoplastic case (do not submerge it) and runs up to three years on a user-replaceable CR1620 coin cell.
What it does not do: detect a CME. Faraday Defense is explicit that CMEs are very low-frequency events that do not couple energy the way E1 and E2 do, so the Pulse Tag is not designed for them. For the RV owner that makes it the detector for the road, where there is no power line to watch anyway: it goes on the day pack, the console or the key ring and tells you, wherever you are, that a fast pulse has happened.
DEFCON EMP Alert System: the plug-in
The DEFCON EMP Alert System plugs into any standard 120 V outlet and watches both the ambient air and the power line. Faraday Defense fits it with two circuits: a high-speed one that catches E1/E2 disturbances as brief as nanoseconds, and a second that continuously monitors the line for the E3 overvoltage and undervoltage that follow an EMP or a CME. Three distinct alarms tell you which it saw: a short beep for an E1/E2 pulse, a long sustained tone for an E3 overvoltage and a pulsing beep for an E3 undervoltage, with red lights on any detection. It draws under 50 mA, about the same as a 5 W nightlight.
The purpose, in Faraday Defense's words, is time: knowing that line voltage is going dangerously high or low gives you a chance to open the main breaker and to warn the rest of your family or group. In an RV on shore power the same logic applies to the pedestal cord. It plugs into any standard 120 V outlet, which puts it in a home, a shop or an RV on shore power, and the obvious place for it is an outlet near the door or the power panel where the alarm will be heard.
DEFCON Home Switch: detection plus action
The DEFCON Home Switch is the only one of the three that acts on its own. It detects an event the way the EMP Alert does, then drives a linear actuator that flips the main breaker off, disconnecting the building from the grid. A button on the unit lets you move the actuator forward or back by hand, and a green light shows it is armed. Faraday Defense says it mounts on most residential breaker panels and includes optional hard-wiring instructions; it is patent-pending and made in the USA.
Two practical notes. First, this is a device that works on the main breaker of a building, so plan on an electrician for the install and check that your panel's main breaker is one the actuator can reach. Second, it does the one thing the EMP Alert asks you to do: pull the main. If you are away from the house, asleep or simply slow to react, the Home Switch does it anyway. A trip leaves the house off the grid until someone resets the breaker, which is what you would want after a real event.
The three detectors side by side
| Detector | Detects | Power | Response | Where it lives |
|---|---|---|---|---|
| DEFCON Pulse Tag | E1 and E2 pulses (about 20 ns); not CME | CR1620 coin cell, up to 3 years | Audible alarm within 100 ms; reset button | On you: pack, coat, key ring, equipment |
| DEFCON EMP Alert System | E1/E2 pulses and E3 over/undervoltage from an EMP or CME | 120 V outlet, under 50 mA | Three distinct alarms plus red lights; you open the breaker | Home, shop, or an RV on shore power |
| DEFCON Home Switch | Detects like the EMP Alert | Plug-in, or hard-wired by a licensed electrician (Faraday Defense's two install options) | Linear actuator flips the main breaker off; manual button; green armed light | The building's main breaker panel |
Detection ranges, response times and power figures are Faraday Defense's ratings.
Wearable or plug-in?
If you spend most of your time in the rig or on the road, the Pulse Tag is the one that is always with you, and it needs no outlet. If the rig sits on shore power for long stretches, or the question is really about the house you leave behind, the EMP Alert gives you the E3 line monitoring the tag cannot. The Home Switch is a third category, for the owner who wants the main breaker handled whether or not anyone is there to hear an alarm.
How they pair with the vehicle kits
A detector tells you something happened; it does not stop the energy. That is the job of Faraday Defense's suppressors. On a tow vehicle or motorhome the 4-piece EMP Vehicle Protection Kit (one T.R.A.P. 12V plug, one T.R.A.P.-B for the battery, two high-saturation ferrites) or the 7-piece diesel kit clamps the fast E1/E2 transients at the socket, the battery and the leads, and the DEFCON Vehicle module adds a 270,000 A surge path across the battery. Those parts work whether or not you know an event has occurred; what the detector adds is the cue to act on everything else: shut off the inverter, unplug the pedestal cord, leave the Faraday bags closed. Which parts go where is in the vehicle protection kit guide, and the storage side is in what to keep in a Faraday bag.
For the house, the Home Switch and the EMP Alert sit alongside Faraday Defense's home ferrites: the 0.72" whole-house ferrite for the feed cables at the panel and the 1" broadband and 1" high-saturation ferrites for heavy solar and inverter leads. If you already have a home battery such as those in our Anker SOLIX home backup guide, the detectors and ferrites are the layer that sits in front of it.
FAQ
Will the Pulse Tag warn me about a solar storm?
No. Faraday Defense states it is not designed for CME detection. The EMP Alert System and the Home Switch cover the E3-type disturbance a CME produces on the power line.
Does the EMP Alert protect my electronics?
It warns; it does not suppress. Faraday Defense's point is that the alarm buys the time to open the main breaker and warn others. Protection is the job of the ferrites, the T.R.A.P.s and, for a vehicle, the DEFCON Vehicle.
Can I use the EMP Alert in my RV?
Yes, on shore power. It needs a standard 120 V outlet, so it runs wherever the rig is plugged into a pedestal. It needs a 120 V outlet, so it does not run on a 12V-only rig that is off grid; the Pulse Tag is the detector for that case.
Does the Home Switch need an electrician?
It mounts to the panel with two install options from Faraday Defense, plug-in or hard-wired, and Faraday Defense says the hard-wired install must be done by a licensed electrician. Either way, have the actuator's reach to your main breaker confirmed before you rely on it.
Where do the detectors ship from?
Every Faraday Defense product here is genuine, covered by Faraday Defense's limited lifetime warranty to the original retail purchaser, and ships free to the lower 48 states, with tracking by email. See the full Faraday Defense range, or ask us which detector fits before you order.