Joule Lamp

[Lynxsteam]

People make goofy Videos when they hit the 1000 subscribers mark, so I made a video celebrating a lot of my videos and tidbits of my life.  I called the lighting of two bulbs with a 9 volt a "parlor trick" because without explanation it is just a novelty.  Really no trick.  The amp draw is about 580 ma at 8.75 volts.  Why are the bulbs so bright?  Dunno!

I mis-spoke calling them 15 watt bulbs, they of course are together 15-16 watts at full brightness on grid.

I think too, this is proof that a larger coil has more capacitance, just like a larger battery has more ampacity.  When this Bad Boy fires it sends a lot of energy to the bulbs.  The only thing I don't like is this one rings a little.  It rings at the battery and the tube.  Not as bad as an E-Core, but its annoying.  Today I was running two bulbs and through an aluminum wire wrapped around a fluxed welding rod in some water and there is definitely a lot of bubbles and no heating.  I didn't want to try lighting the gas, because so far the day has been pretty nice!

[PhiChaser]

Hey, I just wanted to make an observation about the wire guages you are using because I think this is VERY important in how these coils interact with each other. Just like length of coil, number of turns, etc...
14AWG conductor diameter in inches: 0.0641
20AWG conductor diamer in inches: 0.032
Notice anything?
So if we take that idea and apply it to a smaller size wize:
24AWG: 0.0201
30AWG: 0.01
Any thoughts?
PC
EDIT: Yes, I understand the smaller wire can't handle as many amps.

[Lynxsteam]

PhiChaser,

I know what you are getting at, that the diameters don't make sense.  Vinyl coated PVC insulated primary wire of 14 awg stranded copper wire is about 0.125" Diameter (depends on manufacturer).  20 awg magnet wire is 0.0319" diameter.  Its is difficult if not impractical to have the wires perfectly next to each other when winding.  If it were possible then for a nine inch length we would have 75 turns primary and 281 turns secondary (843 total).  Its better to shoot for 73-75 turns primary and 258 secondary (774 total).  This gives roughly the 10.6:1 turns ratio. 
So if changes in the size aircoil are made using different wire sizes, its best to calculate based on wire diameters.

My large aircore uses 18 awg secondary and 12 awg insulated stranded primary.  120:1200 turns.

[JouleSeeker]

...

My large aircore uses 18 awg secondary and 12 awg insulated stranded primary.  120:1200 turns.

That is impressive, Lynx.

  As we have discussed, measuring output-power can be tricky from a device such as this, and a simple water calorimeter was suggested by Chet and me.

To follow up on this idea, I've done a short vid this morning -- which shows a very simple water calorimeter and how I tested that it can quite useful and reliable:

http://www.youtube.com/watch?v=4ICpD37usIE&feature=youtu.be

One needs to be able to operate the device with the output power going into a simple resistance, and I think we're approaching this point.

The text:
Today I set up a simple water calorimeter, to measure output energy and power with decent accuracy.  I have other calorimeters, but this is to show how straightforward it is, and to allow the experimenter to get a handle on output power -- which can often be tricky with output that is far from DC or sinusoidal AC; for example, from a blocking oscillator or Don Smith-type device.   


   Water is weighed in grams with a scale that cost about $10 and placed in a styrofoam cup.  Or you could use a graduated cylinder, 1ml = 1gram for water. Temperature change (delta-T) is measured in Centigrade using a TK thermometer, that cost about $10 also.  For this check, I used a power supply to give me 14 V and measure the current; I could have used a battery at 12 V (for example) and an ammeter.

The power is dumped into an "immersion heater" (about $7) which is simply a resistive coil; this is stirred in the water to heat the volume of water.  At room temp, the resistance was 53 ohms.  Time is measured with a stop-watch on my wrist.  Easy.

Result:
Power-input = 14V @ 0.264A = 3.7 Watts input.
Energy output = Qheating = 4.19 J/g-degC (H2Omass) (delta-TempC) =
   4.19 x 316g x 0.9C = 1192J
This heating required 5min19s = 319 seconds, so the output power measured in the calorimeter is:
Poutput = Eoutput/Time = 1192J/319sec = 3.7Watts -- which agrees very well with the input power.

Thus, we have tested the simple water calorimeter and shown that it WORKS!  It is a valuable tool for measuring output energy and power.

In another test, I ran at 12V @226mA = 2.7W and the water heated from 21.2 to 21.6 Degrees-C in 210S.  So
Eout = 4.19 (316g) 0.4C = 531J, and the power-out is
Pout = 531J/210s = 2.5W, compared to the known 2.7W in. 
To get decent accuracy, one needs to run for a long enough time to heat the water by nearly 1deg-C or so.

[Lynxsteam]

This is excellent!

My team had a similar problem to solve in testing large alternator output power.  We cross checked meter readings with temperature rise.  We used nine 1500 watt heating elements in various series and parallel arrangements and ran the alternator through its rpm range.  We couldn't find any better way to measure true power output, because we needed a load, and most loads will change resistance when heated so they are a moving target.

Any changes in resistance occurring due to heat are captured at the output with your technique.  We also recorded temperature rise in the alternator.

Now the only question is whether you can be sure running the blocking oscillator output through a resistive load is the same as what it would be through the LEDs.  The only way I might suggest is to find a resistive load that runs the circuit at the same frequency as the LED load.  LEDs give off light energy and heat, whereas heating elements give off primarily heat.  Seems like what you are testing is power output at that frequency into that specific load.