These operate at elv (extra low voltages) between 3 and 12 V. The single bell, buzzer and many models of chimes are powered by dry batteries but the more powerful chimes and intricate bell systems have to operate from mains transformers. Usually a transformer is preferable for any bell or chimes. Where an illuminated bell push is used a mains transformer is essential as the lamp of the push would exhaust a battery in a day or so. Read the rest of this entry »
Most, if not all, people know that mains electricity in the home is lethal. This means that if you come into contact with a live terminal, live wire or metalwork, which because of a fault is charged with electricity, you will receive an electric shock which could be fatal.
Electricity at the mains voltage of 240 V is present at every ceiling rose, lampholder, switch, socket outlet and other outlets. It is also present at every electrical appliance connected to the mains when plugged into a socket outlet and the switched socket is ‘ON’. Read the rest of this entry »
Most people have a healthy respect for electricity and understand that it can be dangerous — even lethal — if misused. Electricity at all voltages should be respected. Anyone who does not follow the basic rules of electricity is not only a danger to himself but to everyone around him. Electrical accidents are avoidable: most are due to plain carelessness and failing to follow the basic rules.
There are about sixteen million homes in Britain supplied with electricity and each one contains an average of about 25 electrical appliances. Given the sheer number of items, it is perhaps surprising that there are fewer than 80 fatalities from electrical accidents a year. Although this represents only a small percentage of the entire population and represents only one per cent of the 8,000 deaths each year that result from accidents in the home, the figure is still far too high. Read the rest of this entry »
All the mains appliances featured here have some kind of mains cable. Problems with the electronic cables of portable appliances are quite common, especially those that are moved around constantly while in use, such as vacuum cleaners and hedge cutters.
The problems can range from a simple break in one or more of the conductors, which would render the appliance open circuit, to the breakdown of the cable’s insulating properties caused by damage, fatigue or neglect, leading to the risk of electric shock or fire. Electronic cables and extension leads must be checked regularly and thoroughly.
There are several different types of flexible electronic cable in two-core and three-core configurations on the appliances shown here. It is important to remember that two-core electronic cable is used only on double insulated appliances; three-core electronic cable is used on all items requiring an earth connection. Read the rest of this entry »
Most labour-saving household appliances contain an electric motor of some description. They are the workhorse of these appliances and most of them are capable of coping with the work loads inflicted upon them. However, some motors, either through poor design or as a result of manufacturers’ cost limitations, are inadequate for the job they are required to do. Adequate or not, at some point it is almost inevitable that they will fail or simply wear out. To delay this, use the appliance with some care and attention, be aware of its limitations and carry out regular inspection and servicing. This will prevent small problems escalating into major ones
Not only do the sizes of motors vary greatly between products, so too do the ways in which they work. To diagnose faults successfully and service or repair appliances, a working knowledge of motors is essential. The following provide a basic introduction to the various types, a description of how they work, the appliances in which each may be found and their particular advantages and drawbacks. Specific problems can be found on individual appliances. Read the rest of this entry »
Throughout this post, references are made to meters and their use in continuity testing of individual parts of the appliances and their connecting wires. All testing and checking for ‘open’ (not allowing for current flow) or `closed’ circuit (allowing current to flow) must be carried out using a battery-powered multimeter or test meter. Testing should never be carried out on live items under any circumstances. Appliances must be disconnected from the mains supply. Read the rest of this entry »
There are two main types of shavers: fully portable (powered by batteries, either dry cell or nickel cadmium rechargeable), and mains powered which usually incorporate a variable voltage option switch (110-130 volts or 210-240 volts). Correct maintenance is essential if they are to work efficiently and have a long and useful life while simple care and cleaning will greatly improve their smooth operation and reduce the likelihood of recurrent breakdowns. Read the rest of this entry »
There is what seems to be an ever-increasing range of labour-saving equipment capable of tackling the wide variety of repair and building work now taken on by the D-I-Y home-owner. Tools that were once used in only professional workshops and factories are now quite commonplace around the house. Electric drills, routers, grinders, saws and planes are now produced to meet the demand from the rapidly increasing army of D-I-Y enthusiasts. The diversity and range available is vast. They are all based on an electric motor taking the place of manual effort. Each has a powerful motor for direct drive or reduction via a gearbox or electronic control and can be found in mains or battery powered versions in most instances. Read the rest of this entry »
