Alarm problems.
Notice:
Poor design or fitting of alarms can cause false alarms or failure to be triggered
when they should. The type and positioning of sensors is important, so should be
chosen by proper alarm installers.
Due to the problems of noise, laws have been put in place regarding alarms. Anyone
making, modifying or fitting alarms should be fully aware of the law and technical
issues regarding alarms. As well as specific alarm laws, it should be noted that
having constant false alarms may be considered to be "anti-social behaviour".
The author does
not encourage dabbling in circuits that you do not understand
or the fitting of alarms by people unaware of correct fitting methods.
What is the problem?
Burglar alarms triggering for no apparent reason are a known problem. On some estates,
where alarms are on almost every house, alarms can be heard often going for no reason.
The most common problem associated with this is that alarms may be ignored. In fact,
police may refuse to attend most cases of alarms being triggered. If an alarm is
often falsely triggered, it may lead to people making complaints about the noise.
What can suffer from this?
Any burglar alarms, although wireless systems can be more prone to problems.
Who's fault is it?
This depends upon the type of alarm and the cause.
Clearly, a wired system which does not use
RF should not pick up any signals. In such cases,
picking up any external signals suggests poor alarm design. However, if you use
excessive power then you should not be surprised if your signal causes problems.
Although wireless systems do use
RF,
as the frequency is much higher than CB, a legal
CB radio should not interfere with any burglar alarm.
In cases of shared band interference, I would blame the problem on the government
department who allocated the frequencies.
What causes it?
This depends upon the type of alarm and the situation. Possible causes include:
Poor alarm fitting
Faulty alarm sensor
Poor alarm design
Sharing of band
Smart burglar using tactics
Excessive power from CB
Problems with CB
