Posts by jeff

Ebay comes to the rescue again. I received a used Lumasense IGA-5 IR thermometer today. It is German built and looks like a good piece of equipment. More importantly, its wavelength sensitivity is in the 1.45-1.8 um range, which corresponds closely to the Planck blackbody spectral peak for objects in the 500-1500 C range. Designed to operate at an FL of 800 mm, it's spot size is only 4 mm, considerably smaller than the diameter of the alumina tube would with heater wire. The device requires an oddball connector which I'll need to order. Then I can calibrate it against a thermocouple, setting the emissivity, as required. Note that I plan to use the IR thermometer only to monitor the surface temperature of the alumina tube for temperature feedback control. Actual power generation will be measured via a flow calorimeter.

Jeff

For the sake of argument, suppose that Rossi's patent permits one to build devices that yield reliable power and that the process can be scaled to commercially useful power levels. Also assume that major power governments such as USA, China, Russia, etc. are convinced that the process is real and can replace a significant amount of fossil fuels. Does any one think that, if national energy security is at stake, any of these powers is going to honor a patent? Remember, we went into Iraq in an illegal war on the hope of securing oil. Just a bit of realpolitik here.

Jeff

The following plots demonstrate why airflow calorimetry is so much more accurate than attempting to interpret power output from surface temperature. The first plot illustrates Kanthal wire wound around an alumina tube that is supported in free air by two ceramic supports. (I'll add ceramic cement when it arrives). Foil #2 shows the surface temperature as measured by a type K thermocouple inserted in the center of this tube. (There may be some small difference between temperatures there and on the wire surface, but it should be small). Note that the power applied vs. temperature rise curve is not linear, nor is it quadratic or exponential. Temperature dependent convective effects are certainly coming into play here. The last foil shows a previous run at lower power where the cell is inside a constant thermal mass flow calorimeter. Power vs.temperature is nearly linear and is much easier to interpret. Since calorimetry inherently integrates emitted power over the entire surface of the cell, hot or cold spots do not create errors. Once I get the new apparatus completed the first run will be done with an empty cell over the full temperature range: up to ~1300 C. For safety and reliability reasons I do not plan to go to higher temperatures.

BTW, has anyone seen any data on COP temperature dependence? I know the Lugano team used ~1400C, but is the onset of excess heat sudden, or does it happen at lower temperatures also? Certainly, once I get things built this is one parametric sensitivity that I'll investigate.

Jeff

I recall noting in the Lugano report, that Rossi handed one of the testers an envelope of fuel powder who then poured it into the cell, with no mention of using a glove box or handling the fuel under inert gas. Am I the only one who is surprised that Rossi, who should certainly know better, would be so cavalier about handling a mixture that contains LiAlH? Perhaps the LiAlH was coated with some passivating agent, but there was no mention of any such thing in the report.

Jeff

Due to the dangerous nature of LiAlH I have elected to build a cell that utilizes metallic Ni, Al and Li, and H2 is supplied externally. The Al is present to act as an oxygen getter, reacting to produce Al2O3. I just received a few 10s of grams of Li from a Chinese source, sealed under Ar in packets. There they will stay until I can store the Li under paraffin oil. BTW, does any one have a source for paraffin oil?

H2 is potentially dangerous if improperly handled, so I plan to purchase the smallest size cylinder possible from my local welding shop. Also, all the plumbing between the H2 tank and the cell is 316 SS tubing connected together with brazed VCR fittings utilizing Ni or Cu gaskets. These are the same type used in the semiconductor industry where they routinely handle arsine, silane and other nasty gasses.

Again, keep the quantity of hazardous materials in the cell as small as possible. Ditto for any stored materials.

Jeff

Quote from GlowFish

Looks great. Just some quick questions. Does the DAQ have its own input filter? Perhaps add small 10n cap and maybe a load resistor across the output of the Op-amps U1 and U2 and from the 7.5V to GND at the pins of the op-amps (U1, U2 and U3) to decouple HF noise especially if the DAQ is going to be at the end of a lengthy cable. The 7.5V reference is generated by a linear adjustable regulator which is source only so your 7.5V reference "sink" impedance is basically only your feedback network. Perhaps add a small 0.1uF ceramic in parallel with your output electrolytic to sink HF noise as C6 might have fairly high ESR. I also noticed that the LM317 regulator will only regulate properly if it has a minimum load of about 10mA. May I suggest R2 = 560 ohm and R1 = 110 ohm?

The DAQ has input filters but they are quite small to permit DAQ operation into the 10s of KHz. In the past I have run the DAQ without any additional filtering and have not encountered any noise problems. Most of the measurements are differential, so that helps, and I use shielded cables as well. Also the output voltages generated by the air flow temperature monitor and power supply controller circuits are scaled to give a 5V full scale output.

The LM317 requires that the load in parallel with the programming resistors sink at least 50 ua. The two load resistors I'm using total about 1460 ohms, so just the programming resistors, by themselves, sink ~5 ma. The values you specified would work also. However, I have since decided against using a floating 7.5V reference and elected to use +/- 15V supplies to the INA114 instrumentation amplifiers. That eliminates the need for the LM317. On page 4 the 7.5V reference is replaced by a precision 5.00V reference, REF02, manufactured by TI.

BTW,my day job is a signal integrity and microwave designer at Intel.

Quote from AlainCo

Is it stupid to say others could be adapt it to waterflow calorimeter ?

maybe the LM sensors are not enough precise for liquid calorimetry ?
sure driving water "fan" may be a bit different too...

too bad I'm too busy to participate... 20 years ago...
best wishes.

Not at all. Sealed thermocouples are readily available, as are flowmeters. Both are available from the Omega Corporation which readily sells to amateur scientists, Being incompressible, liquids provide an easier environment for doing calorimetry since the volume remains nearly constant with temperature. If there is a phase change, such as boiling, then the problem becomes a bit more difficult as the heat of vaporization must be included in the calculations.

Attached are the schematics for the signal conditioning and control electronics for the LENR apparatus I'm building. There are three subcircuits: inlet/outlet temperature monitoring, fan airflow control, and a temperature controller that drives a programmable power supply. The last circuit assumes an IR thermometer or a high temp thermocouple controller with 0-20 ma current loop output. This is an industry standard. All the circuits have been simulated and appear to operate correctly. Depending on your particular setup some circuits may be of interest.

Jeff

Attached is a short paper describing an E-cat replication attempt. It differs slightly from Rossi's configuration in that it utilizes an open cell, where hydrogen gas may be introduced from an external source. This eliminates the need for LiAlH4, but does require metallic Li, which is slightly less hazardous. The paper describes the cell as well as support equipment, particularly the calorimeter. Much of the apparatus was built previously for a Celani-type of experiment. I hope to have the electronics built within a month and start calibration shortly thereafter.

Jeff