Scioly.org

Only my personal thoughts, but...

-For concerns with 3.d., I would be satisfied if a competitor had a removable filter placed over the photocell/light arrangement mentioned. The exact construction can be observed with the filter removed and the action can be observed during the run assuming that you use a sufficiently bright light source. That way you can protect the photocell from ambient conditions, but it is quite clear when the light is activated (so the action of the light turning on is "visible").

-LED sounds like an argument waiting to happen concerning heat generation. 12V halogen bulbs are super easy to come by in small sizes and provide both intense light and heat.

andrew lorino wrote:My concern with this task is that rule 3.d would seemingly prevent isolating the light+photocell in an opaque container, complicating detection. The best idea I had for a light source was an old zirconium flashbulb, which would (hopefully) cause the photocell to emit a burst of electricity. A capacitor could block the nominal flow of current, but a spike of power could transfer through (I think). Then it could go to some sort of logic gate (edit: an SCR?) that keeps itself open after the pulse.

So, I successfully made a thyristor/SCR out of BJT's and resistors over the weekend. Now to test my capacitor theory...

andrew lorino wrote:So, I successfully made a thyristor/SCR out of BJT's and resistors over the weekend. Now to test my capacitor theory...

The solar panel can reliably activate the SCR, with bright light. The capacitor does block constant flow, but won't let a moderate increase up to activation level through. Without it it worked fine enough, although testing with an actual flashbulb will be needed. A blue transparent plastic sheet has noticeable effect on distance light had to be to trip the SCR, it seems logical to me that the sheet should be the same color as the solar panel as it shouldn't absorb any of that wavelength. Of course, the sheet could be using a combination of pigments in which case all bets are off. This could be used to allow the device to be visible and not be triggered by background light. Next step: Get a solar panel that isn't 12 years old and get some flashbulbs.

The task says to use the exothermic action that produces light to activate a photocell. Would it still fit within the rules if one were to use infrared or ultraviolet light? It doesn't specify whether we have to use visible light.

ctrlj wrote:The task says to use the exothermic action that produces light to activate a photocell. Would it still fit within the rules if one were to use infrared or ultraviolet light? It doesn't specify whether we have to use visible light.

Yes, you could, in theory, but wouldn't visible light be cheaper/easier?

I know this sounds like another argument waiting to happen, but if you were to use an array of LEDs, would this count as exothermic?

daydreamer0023 wrote:I know this sounds like another argument waiting to happen, but if you were to use an array of LEDs, would this count as exothermic?

Why couldn´t you just use a small halogen light?

ScottMaurer19 wrote:

daydreamer0023 wrote:I know this sounds like another argument waiting to happen, but if you were to use an array of LEDs, would this count as exothermic?

Why couldn´t you just use a small halogen light?

Something came up from tryouts and I wanted to clarify.

daydreamer0023 wrote:

ScottMaurer19 wrote:

daydreamer0023 wrote:I know this sounds like another argument waiting to happen, but if you were to use an array of LEDs, would this count as exothermic?

Why couldn´t you just use a small halogen light?

Something came up from tryouts and I wanted to clarify.

I mean technically an LED generates heat but its not very apparent

ScottMaurer19 wrote:

daydreamer0023 wrote:

ScottMaurer19 wrote: Why couldn´t you just use a small halogen light?

Something came up from tryouts and I wanted to clarify.

I mean technically an LED generates heat but its not very apparent

So do you think that the ES will actually measure to see if it heats up? I mean, light=heat so in that regard they must be exothermic.