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A Closer Look At How Alarm Systems Work

It’s thanks to that patent that we don’t have to rely on dogs or livestock shrieking to warn us of potential intruders.

Read on to learn all there is to know about alarm systems, including what they are and our handpicked favorites. 

What is an Alarm System?

Alarm systems, also known as home security systems, are a reliable and comprehensive security measure you can install to protect your home. Like an electronic spider’s web, a network of sensors placed in a range of locations all lead back to a central monitoring system, referred to as an alarm control panel. 

Through this, they can detect a range of potential threats throughout the home, and quickly alert either yourself or the authorities of a break in.

Purpose of Alarm Systems

You’d find it difficult these days to find a home with only one route of access. It’s because of this that alarm systems also shine in their ability to monitor multiple methods of entry simultaneously. 

How Do Alarm Systems Work to Improve Security?

When a sensor is tripped, it sends a signal to the alarm control panel. The system will then respond based on the programming settings for that zone. For example, one sensor might only cause alarms if activated while the system is armed, while others may cause alarms at any time, regardless of the current system status. 

They can also be programmed to have a delay period, which gives the user a short period of time to disarm the system before an alarm signal is sent out.

When an alarm does occur, the system sends out an alert to a central monitoring station. Most alarm systems available today use an internet communicator or a cellular communicator to send out signals. There are also dual-path modules that use both IP and cellular communication. 

Credit: Alarm Grid

Monitored alarm systems contact relevant authorities (the police in the event of a burglary, the fire department in the event of a fire) through a central monitoring station that operates 24/7.

A trained dispatcher will immediately notice the alarm and begin contacting the end user and/or the local authorities. If the dispatcher does not receive verification that the alarm was false, then the appropriate authorities will be sent out to the premises as soon as possible.

There is also what is referred to as self-monitoring, or unmonitored alarm systems. These are significantly more affordable, since you won’t have to pay for access to the monitoring team (which will be paid either monthly or annually). Here, the alarm system does not contact a central monitoring station. Instead, it alerts the end user directly through a text message or email.

This is done using an interactive service platform like Total Connect 2.0 or Alarm.com. More affordable unmonitored alarm systems will have no notification services at all, and simply sound a loud siren to draw attention.

It is then up to the end user to contact the appropriate authorities. This can be a good option if the user is confident that they can quickly and consistently respond to texts or emails letting them know that something may be wrong (and doesn’t want the cops showing up unannounced in the event of a false alarm!)

Credit: This Morning

For businesses, storefronts, and public spaces, a monitored alarm system is crucial to staying as secure as possible: an unmonitored alarm system will be of minimal use. For regular homes, unmonitored alarms will suffice (they are far more affordable). But if the property is especially large, or the occupiers are frequently absent, consider installing a monitored alarm system for additional peace of mind.

Different Types of Alarm Systems


The name is self-explanatory: wired alarm systems are hard-wired into your property. Each part of the system, including the sensors and the control panel, are connected with wires fed through or along the walls and floors of the building. Don’t be mistaken: modern wired alarm systems will likely also feature internet connectivity just as wireless ones do; the ‘wires’ are simply indicative of how it is powered and connected.

Highly reliableRequires professional, expensive installation
Zero delay in reaction timeCan be unaesthetic if not well-hidden
Powered by a central power supply, so batteries won’t have to be replacedPower outages in the property could threaten security

Our recommendation for wired alarm system: ADT. Free quotes available.

adt products
Image via ADT

Why? With over 148 years of experience, it’s fair to say ADT is among the most widely recognized and respected security providers. Easily find a package that works for you, whether you’re a business owner or homeowner, and combine different products and services tailored for your needs. 

K Lodhi on TrustPilot‘ADT is a great company to deal with, friendly and honest with knowledge to guide on home security.’
koups on TrustPilot‘Very thorough check up – sorted out the problems with my alarm.’


‘Wireless’ alarm systems aren’t the same as ‘Wi-Fi’-enabled alarm systems, though it’s an easy mistake to make based on the name. As mentioned, many alarm systems will also combine internet functionality, but the ‘wireless’ here simply indicates that radio frequency is used to transmit data between the sensors, control panel, and the alarm itself. With no wires, they’re easier to install.

Easy/fast installationLimited signal range means they’re best suited to smaller spaces
Maintains the integrity of walls and floorsEasier to hack
Battery power means outages won’t affect your securityBattery will need to be replaced, meaning there could be downtime if they run out

Our recommendation for wireless alarm system: eufy 5-Piece Home Alarm Kit. From $159.99

eufy products
Image via eufy

Why? One of the more inexpensive options, eufy has managed to make a totally comprehensive alarm kit well suited to casual settings, like homes and apartments. Best of all, there’s no monthly fees, which is certainly something that’s hard to come by when searching for alarm systems.

Tyler on eufy‘Highly recommend getting this system! Easy to install, easy to use, no drilling necessary (it’s optional). Great price! Cameras and doorbells are also great!’
Roch H. on eufy‘So far it works very well, no false alarms unless I forget to undo when I walk in the door! The interior siren is quite loud, at least for a townhome. The door sensors are a little large (clunky) looking. It integrates well with our new Eufy video doorbell and Google Home.’


Regular motion sensing alarm systems that use infrared sensors can be easily set off by a furry friend parading to and from the property, especially if they are particularly large. Pet-friendly alarms may therefore be necessary for many households. These have super sensitive infrared sensors that will recognize the size of the pet’s heat signature, ignoring it if it falls below a certain threshold.

Less likely to trigger false alarmsEncourages presence of cat flaps, which can be a major security risk
Won’t frighten pets unnecessarily with loud false sirensHarder to find on the market than regular alarm systems
Customizable sensors

Our recommendation for pet-friendly alarm system: SimpliSafe. Shop packages or build systems. 

SimpliSafe products
Image via SimpliSafe

Why? One of the few companies that clearly advertises its sensors as pet friendly, SimpliSafe designed a ‘precision human-form detection algorithm to differentiate between humans and our furry companions.’ This means that anything under 23kg will be ignored, saving you the hassle of constant false alarms.

Zach Bradshaw on TrustPilot‘All of the motion sensors, door contacts, and cameras, are discreet and fit perfectly into any style of home. The best part about the motion sensors is that they are pet safe and can have their sensitivity changed at the click of a button.’
Caroline Mcmillan Browse on TrustPilot‘Not only is it value for money, easy to install (honestly!) and very configurable to your own needs – it also is a wireless smart system which you can control via your phone app and with 24/7 monitoring. And it is so easy to use day to day and pet friendly. Cameras are a great add too.’

Smart alarms

Smart products have transformed our homes into more easily manageable spaces, where our entertainment and security can be combined into a singular automated process. No surprise, then, that smart alarms are fast becoming a popular option for homeowners looking to get a firmer grip on their property’s security measures, usually with the call of their voice. Smart alarms can interface with other smart products, like Google Home and Amazon Alexa, so that processes can be simplified and automated.

Easy setup and integration into existing productsVoice control can be used by children and strangers
Controlled via voiceUsually requires existing smart products, like a screen device
Notifications keep you informed of tripped alarms and other information

Our recommendation for smart alarm system: Ring Alarm 5-piece kit. From $187.49.

ring products
Image via Amazon

Why? Similar to eufy’s offering, Amazon-owned Ring’s slightly more expensive (albeit still fairly affordable) 5 piece alarm kit is a perfect choice for homes already kitted out in Alexa-enabled goodies, easily integrating into your smart home. Emergency support comes with a Ring Protect plan, so expect to fork out extra bucks.

Techmeister on Amazon‘Love the concept for this product, it was very easy to install and use. Batteries and double sided tape made the install take an hour for the whole thing vs. days for traditional wired products. Tying into the Ring camera system is nice too. Also, being able to have it professionally monitored is a must and glad to see it exists.’
John Borges on Amazon‘Easy to install and setup. Works great with Alexa. I have echos located throughout my home that can listen to my commands anywhere in the house to arm and disarm the system so I rarely have to use the keypad.’


An alarm system that is ‘monitored’ is one that sends a direct alert to a 24/7 monitoring team (provided by the manufacturer or a third-party service). The monitoring team will likely contact the homeowner to notify them, but will also contact the relevant authorities; police for break ins, fire department for fires.

Extremely secureExpensive upfront cost
Intuitive responsesMonthly or annual fees for upkeep and access to monitoring team
Keeps unoccupied spaces safer

Our recommendation for monitored alarm systems: ADT. Free quotes available.

adt service
Image via ADT


An alarm that doesn’t feature monitoring will simply trigger an auditory warning (and occasionally flashing lights) when the alarm is tripped. This is done primarily to alert someone within the immediate area, but can also help in deterring or frightening off a would-be intruder because of the loud noise and attention it draws to the property. Authorities will not automatically be contacted, making it a significantly more inexpensive option for those on a budget.

May deter would-be intrudersAuthorities will not be notified
Alerts anyone within the immediate area of a break-inThe presence of a siren alone won’t necessarily stop a break-in
Affordable Alarms are likely to be ignored by neighbors, so absence from property carries more risk

Our recommendation for unmonitored alarm system: Tolviviov Wi-Fi 8-piece kit. From $64.99

Tolviviov Wi-Fi 8-piece kit
Image via Amazon

Why? With a price that truly can’t be beat, you get plenty of bang for your buck with this 8-piece, Wi-Fi enabled kit from Tolviviov. With no fees, there is a degree of self-monitoring you can carry out from your phone using the corresponding app, making it perfect for homeowners and apartment dwellers.

whammyman79 on Amazon‘Liked the quality of the product, instructions are poorly written but overall so far a good product. I’m using it in my apartment because the kitchen and master bedroom have sliding doors which I think are easy to break in and the sliding door is on the first floor and my bedroom is on the 2nd floor so if someone tries to get in the alarm will alert me when activated.’
R. Kirkes on Amazon‘This is a simple and straightforward way to install alarm system. The price is also quite reasonable. The only catch is that this alarm system requires 2.4 GHz WiFi.’


How does a burglar alarm system work?

A burglar alarm sounds a siren when a sensor attached to either a door or window detects movement. Monitored alarms will automatically send information to a monitoring team, who will then contact relevant authorities. Unmonitored alarms simply make a loud sound. 

What are the 3 main parts of an alarm system?

An alarm system will generally consist of a primary control panel (where the information gets sent), sensors, and usually a keypad for disarming the alarm.

How is an alarm activated?

A basic alarm is an electric circuit built into an entry point. In a closed-circuit system, the circuit being cut (i.e. by a door being closed) will sound the alarm. In an open-circuit system, the circuit beginning to flow (i.e. by opening a door) is what triggers the alarm. 

How does an alarm siren work?

Though piercing sounds are produced by a whole host of means, the sirens in home alarm systems are generally electronic. In other words, the sound is synthesized through oscillators, modulators, and amps. Some newer alarms, particularly smart devices, may just use a recorded high pitched sound and project it loudly.


The technology behind and incorporated into alarm systems has changed drastically over the last two hundred years, but the premise behind them remains as it always has: make as loud and irritating a noise as possible to attract as much attention as possible when motion has been detected.

They are an essential part of any truly complete security setup. For businesses, storefronts, offices, and larger homes, monitored systems are significantly more useful than unmonitored alarms, and will give you more peace of mind should you be absent from the property. On the other hand, smart alarms can be a great solution for regular use in most homes, since they perform similar functions in a more seamless fashion.