Let's say you have a lot of microwave-based cooking appliances: a regular microwave oven, a microwave cooking pot, a microwave slow
cooker, a microwave pressure cooker, a microwave pizza oven, a microwave popcorn popper, a microwave pot lid, a collapsible
microwave oven, etc. [links]
It struck
me that there'd be a lot of redundant hardware there: a magnetron, a magnetron drive circuit, control electronics, and a
control panel in each appliance. It would be cheaper, and you'd have an easier time moving house, if this redundancy was resolved. To
address this issue, Approximate Industries is developing a modular microwave powerpack, as well as a line of microwave-powered
appliances to which it can be docked. The powerpack contains a 1 kW magnetron, a drive circuit (a modern high-frequency one, not an
old-fashioned and heavy MOT), control electronics, and a touchscreen control panel that also supports voice control. The fancy
features, which cost more than the basic ones, are enabled by needing only one powerpack between all of your microwave-powered
appliances, greatly reducing cost overall if you have more than one such appliance.
The powerpack can be attached by a simple tool-free mounting system to any of the above-mentioned appliances, or future ones. (The
interface will be an open standard, so we expect many other companies to join us in producing both the powerpacks and the
appliances.) The tip of the magnetron is covered by a protective cover that retracts as the powerpack is slid into position to allow the
magnetron to mate with the appliance's waveguide, which also has a sliding cover for the same reason. Other connections are provided
for power and communications between the powerpack and the appliance.
Power can work in two ways. First, you can have a power cord going into the powerpack directly. Second, you can have a power cord
going into the appliance, which then provides power to the powerpack when the powerpack is mounted. This is done using standard IEC
60320 C13/C14 connectors, arranged in such a way (still under development) that a power cord being plugged into the appliance
precludes the mounting of a powerpack that has a cord plugged directly into it, and vice versa. In this way, you can have power cords
associated with all of your appliances, and move your powerpack between them without having to deal with a cord. Alternatively, you
can have two or three appliances nearby, and move the powerpack with associated cord between them, and all of these appliances will
only take up one receptacle, without having to switch cords around.
Communication is over a standard serial connection (specific protocol not yet decided) between the powerpack's control electronics
and the appliance's internal electronics. Blind-mate connectors are used. The appliances having minimal internal electronics allows
them to provide different functions, such as turntable, mode stirrer, food stirrer, temperature sensor, humidity sensor, etc. There is a
capability description/enumeration capability, so that the powerpack knows what features the appliance has. The appliance can even
provide a description of a user interface suitable for operating it, which the powerpack can use to generate a UI to use when attached
to that appliance.
All power for appliance functions is provided by the powerpack, even if the power cord is plugged into the appliance; this means that
everything is consistent regardless of which side the power cord is plugged into.
N/A [2019-10-07]