Remember in the “Good Old Days”, when someone gave you a toaster as a wedding present, and then, maybe 25 years later, someone else gave you a new one as a Silver Anniversary present ...and, perhaps it was even manufactured in your own home town?
Well, those days are gone, and unless you live in Shenzhen China, the toaster is most likely going to be imported.
The old toasters, with their all-metal construction and chrome exteriors, were electromechanical marvels. They worked by means of what I call, “Functional Geometry”. Timing was done by bi-metallic thermal switches, and “pop-up” was accomplished by having the mechanical levers and springs in just the right physical positions to actuate the mechanisms. It was a mechanical “work of art”. These designs, which were analog in nature, were conceived and implemented not so much as a mechanical design challenge, but for economic considerations. After all, the average home toaster needed to have a retail price of between ten and twenty dollars. Novel, inexpensive mechanical approaches became mandatory.
Digital innovation provides the modern toaster with the ability to perform a number of different functions which were not available previously. These include a defrosting cycle, one-sided toasting for bagels, a warming setting, and more. Modern toasters can accommodate everything from thin English muffins through over-sized bagels, with their self-centering internal grates. It is becoming more difficult to find toasters with steel exteriors, as high temperature plastics are less expensive to produce, and provide a “Cool Touch” feature. Each manufacturer has their particular nichrome wire grid design which supposedly produces perfectly balanced toasting.
In today's toaster, mechanical heat sensitive timers have given way to digital countdown, integrated circuit chips. The pop-up lever is held down with an electromagnetic actuator. Still, the primary motivator in modern toaster design is economy. Shortcuts are taken in power supply design (if you can call a few resistors, capacitor, and a diode a power supply). Also a leading cause of toaster failure is the lack of appropriately designed switches for AC control. Beryllium copper alloys are used as switching elements. They are required to switch high loads (between eight and ten amps). But the configuration of these switching contacts make for lots of sparks, and an eventual weakening of their spring action. Sensitive, low voltage digital electronics do not bide well with sparks, high voltage transients and heat.
The electromagnetic actuator can get dirty, and as a result, will not hold down the pop-up lever. NOTE: DO NOT use a Compressed Gas Duster to blow out the crumbs. This gas IS flammable, and heavier than air. The next time the user tries the toaster, it may result in an explosion and fire.
Reading many online toaster reviews reveal a general dissatisfaction with the quality and performance of the modern toaster. Ah, for the good old days...