Hello, I'm trying to demonstrate the effects of Wireless Power Transmission (WPT), but, I must be doing something wrong (or expecting the wrong results). I'm using an NTE586, as a Schotkky Diode, I attach an LED across the leads, and then hold it behind a 600 watt microwave. I don't see any change on the led. A simple voltage read shows no DC Voltage. When I hold the apparatus near an active cell phone, I read .2-1.2 millivolts. I've also held the diode infront of a 802.11b Transmitter, Chatting at 32dBi and saw no change on a voltmeter (00.0mv) If anyone has experience with this could you please point me in the right direction. Am I using the wrong Schotkky, am I expecting too much out of WPT, really all I want to see is the LED light up, or some type of meter change.
On Tue, 28 Jun 2005 09:27:06 -0400, "Ed Neipris" wrote:
___ You'd probably need a better antenna to catch it in. Microwaves are pretty well directed and tend not to be dispersed. Plus your microwave oven should not be leaking any microwaves anyway. I'm also wondering if the diode you are using might be losing efficiency at microwave frequencies. I just finished a project along these lines, but concentrating on the RF range. The reference I used was:
formatting link
Evidently, the name of the game is to extract as much RF energy you can from existing RF field, losing as little as possible in the process. The circuit uses four diodes in a voltage quadrupler configuration. I checked several types of Shottky and germanium diodes, and the 1N34A germaniums seemed to have the lowest, match able forward voltages. I used 100 uFd electrolytics and .01 uFd caps, neither of which seemed to be critical values. I used a 100' 24ga insulated wire L shaped antenna draped over a 6' backyard fence and a copper cold water pipe as a ground. I made a data logger from a PIC16F877A to log the readings to a PC via the RS232 port into a PC text file, and then imported the text file into Excel for graphing. The logger is set to log a data point every minute. I got about 10 day's worth of data for the outside antenna and just got a dipole antenna(see attachments) set up to start logging yesterday. Incredibly, the inside dipole antenna beat the outside antenna! With either one, you can see a pronounced daily step in voltage right at sunrise and sunset. I attribute this to an AM station about 2 miles from my house that is one of those that go from 1000 watts at night to
50000 watts in the daytime. I'm sure if you use something like this you'll definitely see some measurable voltage readings. I wouldn't stop the research on fusion just yet though(hot or cold). Tate mentions that his rig will power a digital clock that uses 1.5 volts at 28 uamps, or 42 uwatts. If your LED requires a forward voltage of 2.5 volts at 10 ma., that's 25 milliwatts, or 25000 uwatts! I wonder if it could even keep an AA NiMH cell trickle charged? How much power did you want to transmit/receive wirelessly?
P.S. Please excuse the length of the PNG file. I've been having trouble with my file conversion utility lately and it's the best I could do under the circumstances.
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On Tue, 28 Jun 2005 09:27:06 -0400, "Ed Neipris" wrote:
___ You'd probably need a better antenna to catch it in. Microwaves are pretty well directed and tend not to be dispersed. Plus your microwave oven should not be leaking any microwaves anyway. I'm also wondering if the diode you are using might be losing efficiency at microwave frequencies. I just finished a project along these lines, but concentrating on the RF range. The reference I used was:
formatting link
Evidently, the name of the game is to extract as much RF energy you can from existing RF field, losing as little as possible in the process. The circuit uses four diodes in a voltage quadrupler configuration. I checked several types of Shottky and germanium diodes, and the 1N34A germaniums seemed to have the lowest, match able forward voltages. I used 100 uFd electrolytics and .01 uFd caps, neither of which seemed to be critical values. I used a 100' 24ga insulated wire L shaped antenna draped over a 6' backyard fence and a copper cold water pipe as a ground. I made a data logger from a PIC16F877A to log the readings to a PC via the RS232 port into a PC text file, and then imported the text file into Excel for graphing. The logger is set to log a data point every minute. I got about 10 day's worth of data for the outside antenna and just got a dipole antenna(see attachments) set up to start logging yesterday. Incredibly, the inside dipole antenna beat the outside antenna! With either one, you can see a pronounced daily step in voltage right at sunrise and sunset. I attribute this to an AM station about 2 miles from my house that is one of those that go from 1000 watts at night to
50000 watts in the daytime. I'm sure if you use something like this you'll definitely see some measurable voltage readings. I wouldn't stop the research on fusion just yet though(hot or cold). Tate mentions that his rig will power a digital clock that uses 1.5 volts at 28 uamps, or 42 uwatts. If your LED requires a forward voltage of 2.5 volts at 10 ma., that's 25 milliwatts, or 25000 uwatts! I wonder if it could even keep an AA NiMH cell trickle charged? How much power did you want to transmit/receive wirelessly?
P.S. Please excuse the length of the PNG file. I've been having trouble with my file conversion utility lately and it's the best I could do under the circumstances.
Charlie ___ Sorry, forgot the PNG file. Here it is in all its hugeness.
I think your diode is too big. It seems to be a 3A diode and so will have too much capacitance. You can get more suitable diodes made by Agilent such as HP5082-2835, but these are harder to get now and you might find it easier to get a surface mount diode. I think HSMS-2822 and similar would work fine. Connect one of these diodes to a sensitive analogue meter movement (e.g. a 100uA meter movement), using wires that are at least a couple of centimetres long. The wires will provide an antenna (maybe not tuned to the right frequency but better than nothing). Now put a cup of water in your microwave, and put the diode 10cm from the outside casing of the microwave, near the keypad is usually a good place.
If you can't detect any current then your microwave is better than mine so tell me what brand you have!
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