Electric Toaster

the toaster is made of a series of heating elements mounted on mica frames and supported on a porcelain base. It is an example of heating by exposed wires and direct radiation. The heaters H are coils of flat resistance wire that are wound on wedge-shaped pieces of mica. They are supported on a wire frame that is formed to receive slices of bread on each side of the heaters. The attachment piece A and the material of the heater is similar in construction to that of the flat-iron. The electric circuit may be traced from the contacts at A and B in the attachment plug by the dotted lines which indicate the wires in the porcelain base. The current traverses each coil in turn and connects with the next, alternately at the top and bottom. The resistance is such as will permit the voltage of the circuit to send through the coils current sufficient to raise the heaters to a red heat. The added resistance of the hot wires decreases the flow of current to keep the temperature at the desired degree.

In a heater of this kind the resistance of the wire may increase with age and the coils fail to glow with a sufficient brightness. The reason for the lack of heat is that of decrease in current, due to the increased resistance of the wires. This condition may be corrected by the removal of a little of the heater coils. If a turn or two of the heater wire is removed, the resistance of the circuit is reduced and the effect of the increased current will produce a higher temperature in the heater.

The toaster is typically a small electric kitchen appliance designed to toast multiple types of bread products. A typical modern two-slice toaster draws anywhere between 600 and 1200 W and makes toast in 1 to 3 minutes. There are also non-electrical toasters that can be used to toast bread products over an open fire or flame.

Modern toasters are typically one of three varieties: pop-up toasters, ovens and conveyors.

In pop-up or automatic toasters, bread slices are inserted vertically into the slots (generally only large enough to admit a single slice of bread) on the top of the toaster. A lever on the side of the toaster is depressed, activating the toaster. When an internal device determines that the toasting cycle is complete, the toaster turns off and the toast pops up out of the slots. The heating elements of a pop-up toaster are usually oriented vertically, parallel to the bread slice - although there are some variations.

In earlier days, the completion of the toasting operation was determined by a mechanical clockwork timer; the user could adjust the running time of the timer to determine the degree of "doneness" of the toast, but the first cycle produced less toasted toast than subsequent cycles because the toaster was not yet warmed up. Toasters made since the 1930s frequently use a thermal sensor, such as a bimetallic strip, located close to the toast. This allows the first cycle to run longer than subsequent cycles. The thermal device is also slightly responsive to the actual temperature of the toast itself. Like the timer, it can be adjusted by the user to determine the "doneness" of the toast. By comparison, toaster ovens are small electric ovens with a door on one side and a tray within. To toast bread with a toaster oven, one lays down slices of bread horizontally on the tray, closes the door, and activates the toaster. When the toast is done, the toaster turns off, but the door must be opened manually. Most toaster ovens are significantly larger than toasters, but are capable of performing most of the functions of electric ovens, albeit on a much smaller scale. They can be used to cook toast with toppings, like garlic bread or cheese, though they tend to produce drier toast and require longer operating times, since their heating elements are located further from the toast (to allow larger items to be cooked). They may also heat less evenly than either toasters or larger electric ovens, and some glass cookware cannot be used in them.

toaster oven

Conveyor toasters are designed to make many slices of toast and are generally used in the catering industry, being suitable for large-scale use. Bread is toasted 350-900 slices an hour, making conveyor toasters ideal for a large restaurant that is constantly busy with growing demand. However, such devices have occasionally been produced for home use as far back as 1938, when the Toast-O-Lator went into limited production. [See www.jitterbuzz.com/indtol.html for a detailed history of the Toast-O-Lator company]

As with so many home appliances, more elaborate toasters and toaster ovens now utilize computer-controlled mechanisms in place of electromechanical controls. Toasters are usually freestanding, counter-top appliances, although some toaster ovens may be hung beneath cabinets.

Sometimes toast gets stuck in a toaster, particularly pop-up toasters, and must be freed manually. As most toasters are in the kitchen, metal knives and forks are typically an easily available tool but can cause risk of electric shock, unless the appliance is disconnected from the main electrical outlet.

Some toasters also have a small round griddle on them for making eggs with toast.