You don't need much power because the device in the toy only needs to transmit for a few milliseconds then shut off. Some transmuter you have pings the device in the toy that acts like a transponder. It only transmits in response to a "ping". So limey it can be powered by a button battery. How to power the receiver? RFID tags are devices that are powered by rectifying the RF energy from the antenna . Crystal sets work this way also. as for logic, the TI MSP430 can run on nano amps of current. and sleep modes use pico amps. So it could be powered by a capacitor that is charge from some powerful AM broadcast station.
It turns out that "energy harvesting" (getting power from the environment) is a hot tops right now. The simplest method would be the solar powered calculator. That tiny little cell runs a uP and an LCD screen. The old mechanical self winding watch was another example of harvesting energy. You could run the receiver and logic on harvested energy and then use the coid cell battery for a transmitter. Your locator device would measure time of flight to the toy and its own location via GPS. As you move the locator it gathers data used for a solution. All the "smarts" is on the hand held locator that has a high power transmitter, sensitive receive, GPS and a computer. The device in the toy is a simple transponder. In "monitor mode" the locator would request a micro-power ping (not using the coin battery, just the capacitor. from the toy and use a large non-mobile antenna and would alarm if the time of flight changed. You'd want some frequency that would go through walls and trees and in some band that is legal for such stuff. ... >> A friend of mine recently suffered a theft so I thought about the >> opportunity >> to embed little marker transmitters in some object usually left in the >> yard >> (like bicycles for example), and have inside the house a system that >> constantly monitors them for unwanted movement, -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
