Hmm, Good points, Scott. Could the bulbs possibly be submerged or partially submerged in an exact amout of water while lit up and then measure the thermal rise of the volume of water? Something about this setup cries "electrocution hazard" to me, but just a thought. David Rieben PS: Adam's "yurtle turtle" mention of measuring the brilliance of the bulb seems to be about the most straight forward approach, assuming that the lux meter and its proper calibration are not prohibitively costly.----- Original Message ----- From: "Scott Bogard" <sdbogard@xxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Thursday, July 29, 2010 4:25 PM Subject: Re: [TCML] Dummy load for optimum cap size Experimentation
Greetings all,I'm not sure an IR thermometer would work, I used one on a plasma globe once that was very cool to the touch, and got crazy readings of thousands of degrees, they were wild and all over the place. If it was a matter of the light emissions of the bulb causing the readings, one would need to cover the false primary with something opaque but a good conductor of heat, so that the IR thermometer would work (but this might overheat the bulbs.) If it was an RF thing, maybe a cage would help? I never investigated it at the time. Just my two cents...On 7/29/2010 8:00 PM, Binny wrote:HI, Wonder why one wouldn't use one of those non contact IR Thermometers? They're relatively inexpensive and fairly accurate. ----- Original Message ----- From: "Gary Lau" <glau1024@xxxxxxxxx> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx> Sent: Thursday, July 29, 2010 7:14 AM Subject: [TCML] Dummy load for optimum cap size ExperimentationI'm gathering materials and plans to perform this experiment - determining the cap size that will extract maximum power from an NST, at 120 and 140VAC input. The power indication will be via monitoring the surface temperature of the halogen lamp dummy load that replaces the primary coil. I plan to test a 15/60 NST, and two 15/30 NST's, all unmodified. I'm having a hard time figuring out how to fasten a thermocouple to the quartz lamp tube. I want the connection to be robust, as there will be considerable thrash as I change NST's and cap sizes, and I don't want lamp/thermocouple coupling to vary. Obviously I'll clamp down the thermocouple wire to the base of the lampassembly (http://drop.io/garylau), but could use guidance on the businessend. I thought about just wrapping many turns of 30 gauge copper wire around the thermocouple wire and quartz tube, but worry that the quartz and copper will have differing expansion rates and might damage the tube. I have high-temperature polyamide (kapton) tape that I can wrap the thermocouple to the tube - not sure how that will fare with the heat. If nothing easy presents itself, I guess I'll fashion a spring clamp to apply gentle pressure to the thermocouple tip and tube. Any thought on this problem or the experiment design would be welcome. Also, I can't seem to locate the table that relates NST size and gap type to suggested cap size. It had been on hot-streamer and mirror sites, but I can't seem to locate it. Regards, Gary Lau MA, USA
_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla