T
treez
Guest
We have “beacons” spread over the countryside which contain microprocessor boards.
These boards (in the beacons) use around 5V, 20mA. -But they have no power source of their own. They get power from a portable handheld “cube” which is fixed onto them when required….but there is no metal contactor….the contact is magnetic….a ferrite core half in the “cube” ends up near a “mating” ferrite core half in the beacon, and thus power can be transferred from “cube” to beacon. It basically forms like a transformer since both ferrite core halves, (in “cube” and in “beacon”) have a little PCB with integrated windings, which couple with the respective core half.
So I guess when cube is fixed to beacon, a transformer is formed, and power can be transferred from “cube” to “beacon”. The core halves don’t actually physically touch when mated…..rather there is a slight gap between them….the reason for this is purely because if they were physically “smashed” touching together then the ferrite might crack.
So what do you think of this “contactless” connection?
Great advantage is its waterproof. And no corrosion of any metal contactors because there are none.
We are thinking of the attached way of coupling power through this “transformer”. That is, using a high frequency (50kHz) sine wave generated in the cube and flowing in the cube "primary" winding. The "secondary" in the beacon will simply full wave rectify it. Do you believe this is the best ploy?
(LTspice sim and pdf schem attached...we will make the L's and C's resonant at 50kHz in the real thing. We will also possibly do pulse skipping so we only send as much power as we need and no more)
I am certain this is already a well-known technique, would you agree?
These boards (in the beacons) use around 5V, 20mA. -But they have no power source of their own. They get power from a portable handheld “cube” which is fixed onto them when required….but there is no metal contactor….the contact is magnetic….a ferrite core half in the “cube” ends up near a “mating” ferrite core half in the beacon, and thus power can be transferred from “cube” to beacon. It basically forms like a transformer since both ferrite core halves, (in “cube” and in “beacon”) have a little PCB with integrated windings, which couple with the respective core half.
So I guess when cube is fixed to beacon, a transformer is formed, and power can be transferred from “cube” to “beacon”. The core halves don’t actually physically touch when mated…..rather there is a slight gap between them….the reason for this is purely because if they were physically “smashed” touching together then the ferrite might crack.
So what do you think of this “contactless” connection?
Great advantage is its waterproof. And no corrosion of any metal contactors because there are none.
We are thinking of the attached way of coupling power through this “transformer”. That is, using a high frequency (50kHz) sine wave generated in the cube and flowing in the cube "primary" winding. The "secondary" in the beacon will simply full wave rectify it. Do you believe this is the best ploy?
(LTspice sim and pdf schem attached...we will make the L's and C's resonant at 50kHz in the real thing. We will also possibly do pulse skipping so we only send as much power as we need and no more)
I am certain this is already a well-known technique, would you agree?