The Intruder Alarm (a.k.a. Burglar Alarm) has been with us for many years now - probably much longer than you might think. The basic concept of an intruder alarm is to cause an alert of some sort to be triggered when a property is breached by an intruder. As you can imagine this is not a new concept and in fact it is a long-standing duty carried out by Guard Dogs, Guard Geese, and of course, Guards. But back in the early 1700’s a mechanical intruder alarm was first produced.
Mr Tildesley, an English inventor, had an idea to connect a set of chimes mechanically to a door lock. The inventor’s advertisement proclaimed: “The bells associated with it are constructed in such a manner that no sooner is the skeleton key of an intruder applied to the lock than the bells begin to chime a plaintive air that inspires such sentiment in the minds of the housebreaker that will doubtlessly prompt him to take precipitous flight.” This idea of causing an intruder to panic and flee remains a central aim of the modern electronic intruder alarm system.
The move to Electricity
In the early 1850’s Augustus Russell Pope, a U.S. inventor from Boston, discovered how to use electricity, magnets, and a bell to create an early electrical version of the modern intruder alarm. His battery operated alarm unit could be used on a window or a door. If the window or door was opened, the circuit would be completed, causing the bell to ring. The bell was mounted on top of the door frame or window opening and fixed into the wall. Wires ran from a spring ‘key’ in the door/window through an electromagnetic relay of sorts near the bell, allowing the current to run constantly once the door/window tripped the spring. The special feature of Pope’s invention was that the alarm could not be switched off by merely closing the windows or doors (the spring switch had to be reset).
However despite the pioneering work of Pope, most people usually assume that someone else was the father of the modern electric alarm system. Namely Edwin Holmes. He was a businessman and founder of the first installation company for electrical intruder alarm systems, who bought the rights to Pope’s invention in 1857. It was he that then led the way in the business of electro-magnetic alarm technology with his “Holmes Electric Protection Company”.
On October 11, 1859, George F. Milliken was issued U.S. patent number 25,753 for improvements he made to the electric intruder alarm. He designed the alarm device to reside in the room where the homeowner slept or would be unaware of potential thieves forcing entry. This design allowed for wire runs from all windows and doors, where each door/window had a spring with a certain amount of creases that signified a specific number of rings on the alarm bell, alerting the homeowner of the precise door/window where entry had occurred. This improvement on the original system forms the basic idea behind ‘zones’ on a modern electronic intruder alarm system.
In 1868 improvements were again made to the electric intruder alarm. Holmes began offering a system with a clock that would automatically turn the alarm on and off. Visually zoned systems were introduced and were often housed in ornate wooden boxes along with the alarm bell. He also began to offer alarm systems with telephone links.
In 1905 The American Telephone and Telegraph (AT&T) Company bought the Holmes business and linked it to their own emergency call systems for police and fire fighting personnel, taking the electric intruder alarm to another level.
Electric Intruder Alarms were first introduced to the UK by Thomas Gunn Limited, who began installing electric intruder alarms in London in 1907. It was considered a specialist trade for many years, over time evolving from electric systems to electronic equivalents, until the 1970s when the invention of the Passive Infra-Red (PIR) detector opened the sector up to a wider range of installers.