Replacement Fobs



As early as 1888, fobs were in use as attachments to pocket watch chains, but replacement fobs didn't make their debut until relatively recently. Over recent decades, fobs came to refer to key chains and specific attachments such as keyless entry door openers, auto starters, garage door openers, and auto alarm controllers. Most car manufacturers include fobs as a component of a new car. But how do fobs work? One stands a good distance away and presses a button on a little plastic device attached to the key chain, and car doors unlock... Amazing! We'll explain a little bit about this miracle invention right here.



Like most inventions, new inventions such as the key-fob are based on combinations of other recent inventions. The key-fob required understandings in material sciences of chemistry and physics that led to understanding semiconductors and the transistor. Then, multiple transistors were combined into single unit devices and the integrated circuits were born. These evolved into devices that were primarily aggregates of either logic circuitry or analog devices (non-logic circuits). Eventually, these two types of circuits were combined to create mixed-signal devices. Concurrent to that, computers on a chip were being developed, called microprocessors.

So we now had advanced semiconductor circuits that could perform control functions. But keyless entry fobs needed a lot more new inventions. Radio communications also made strides during the same period of time, allowing radio frequency communications in the bandwidth of 2 gigahertz and higher. The high bandwidth is important because it means lower power consumption to transmit the same information. Batteries with high storage capabilities were also developed, but at the same time that new ultra-low power transistor types called CMOS and HCMOS were being developed. Small low-power black and white or color displays (the most recent being organic LEDs) have also been in the works for the last 30 years. Combine all these together with a few switches for the user to tell the computer chip what you want to do, and a signal can be transmitted to a receiver on the car that energizes the locks, or enables an alarm system.

Keyfobs, as provided by the manufacturer, do have disadvantageous, but these can be overcome. Auto manufacturers typically charge many, many times more for key fobs than they costs to make. By going to a manufacturer that is not tied to the auto production, big savings can be realized when the buyer is purchasing a fob at a more realistic and reasonable price. Fobs do get lost or damaged, and sometimes they do just happen to konk out. Defective fobs that control door locks and alarm systems need to be replaced, and manufacturers in Taiwan, Singapore, and other Asian countries can provide good quality, reliable replacement units at a fraction of the cost that dealerships charge.