Selfrunning cold electricity circuit from Dr.Stiffler

[DrStiffler]

Hi Dr. Stiffler, I'm the Spanish order, thanks for making these boards available worldwide. Don't worry about the delay.

@all
It's a pleasure to join you all in this adventure.

I'm thinking about calorimetry, I've ordered a decent glass lab thermometer and will get busy with styrofoam, tinfoil, cans etc. I'm looking for the lightest foam available so it has low thermal conductivity and also low thermal capacitance so the calorimeter will react quickly.

In order to measure thermal characteristics of my calorimeter I will take a 1/4watt resistor and run different DC power levels through it, this will give me a known heat source. I will try the resistor below the metal pot and also immersed in the water with the resistor leads varnish dipped to prevent electrolysis action. I'll try and get photos of my calorimeter efforts in a day or so along with some figures regarding accuracy.

@Yucca
Well without exposing your real name, you are one of the Spanish orders. I will say that Spain is really into this as I have already shipped from first batch many to Spain. Anyway if you are waiting I am sorry, my Hong Kong supplier of LEDs said 'no problem, send air mail, get double quick time'. Problem is what is double quick compared to?

I have learned a lesson here, have everything in hand before making the offering (with many extra). When I order something I want it tomorrow and I think everyone else should be thought to be the same. So again all (some 20 of you) the boards are built, get the LEDs, solder them in and ship. Hey the boxes are addressed and Customs Doc's are filled out.

You idea for a calorimeter sounds good, but you may want to consider the following things if you will be using a Heat Exchanger design, 1) Plan on 500mL of water in the exchanger. 2) Use a 1/2W or 1W calibration resistor. The SEC Exciter will be about 3/4W or more. 3) Don't forget stirring, (slow, hand or automated) but that water will have very defined thermal levels and where ever you place the thermometer may be right in one and not be an accurate indication of what is going on on the exchanger.

@All
I will be putting up a video on YouTube in the next 36 hours and will post a link here. It will show how to prepare a SEC15-3 for Heat Measurement in a Calorimeter. A bit of touch up is required and the video will show that.

So stay tuned till I get it edited.

[Feynman]

Got the SEC exciter boards today... I've been playing with these a bit and there is definitely something very strange going on, nothing like this in any textbook.

Using 19.8V supply voltage:

Draw at anode: 13.58mA
Draw at cathode: 13.58mA

Scope probe at neon, at anode of 1N4148 diode:
The best reading I got showed waveform period of 0.07us , for freq= 12.5Mhz-12.98Mhz.  The waveform is complex.  I would not trust this reading.



-Feynman

PS
One interesting thing I discovered by accident... I connected the (+) side of my SEC exciter to my power supply, and then I clipped my scope ground (-) onto the negative side of the SEC, and the neon lit up.

[DrStiffler]

Got the SEC exciter boards today... I've been playing with these a bit and there is definitely something very strange going on, nothing like this in any textbook.

Using 19.8V supply voltage:

Draw at anode: 13.58mA
Draw at cathode: 13.58mA

Scope probe at neon, at anode of 1N4148 diode:
The best reading I got showed waveform period of 0.07us , for freq= 12.5Mhz-12.98Mhz.  The waveform is complex.  I would not trust this reading.



-Feynman

PS
One interesting thing I discovered by accident... I connected the (+) side of my SEC exciter to my power supply, and then I clipped my scope ground (-) onto the negative side of the SEC, and the neon lit up.

I am guessing that your scope is grounded to the service as is the ground leg of your power supply. What is happening is that the power supply ground is being returned through the scope ground. Now if your power supply is isolated (floating on both the -V and +V) then it could be interesting that it is firing through such a high impedance.

If you think this is a bit strange, wait for the video and see some really strange things happen.

@All
The circuit boards are stable, in other words they are compact enough that you can hold one by the edges in your hand and tune it without screwing it up when you sit it back down. You can wave your hand over and around it without detuning, this in most case is not possible with the proto-boards.

If you have not ordered a board and are going to the SEC15-3 is the one that can be played with and worked with, while the SEC15-20 is a demo boards that shows the chaining of the AV Plugs and powering LEDs and a Neon. The SEC15-20 is for study and measurement and not recommended for modification. If you are going to play with it and make some future modifications, then the SEC15-3 is what you want.

I can ship SEC15-3's within 24 hours, but the SEC15-20's are all piled up waiting LEDs.

[Loki67671]

@All,
While I'm waiting on my copper supplies I'm just experimenting with SEC exciters driving BIG 1W LED's. 6 of them at about 850mw in. As you can see I could read by this easily, if they were the white variety.  Avago Technologies ASMT-MB00-NAE00 in case anyone is interested in the data sheets and spec's just Google. I still need to get rid of all of the metal fasteners on my experimenting platform and this will happen tomorrow. I'm changing it all to nylon fasteners and standoffs.

Welcome everybody, good hunting.

Best regards,

Jim

[Loki67671]

Here is a little fun. 139mw input power.  I love exploring this circuit. 

Best regards,

Jim