Recent content by Tone L

I want to build a motion detection system, however I want to narrow field of view. I cannot find a Fresnel lens with a narrower FOV than 30 degrees. Was looking for something around 20 degrees. Can I use an aspheric lens to achieve this, does anyone know?

My thermal resistance is 15C/15W = 1C/W I presume, so I need to find a heatsink that is greater than this value? The joint between the heat load and the heat sink will be coupled well, thermal paste will be used as an interference between the two as well. It will be in a lab setting where the...

Hi, zero education on heat transfer here, need some help. I have an electronics module that generates 15 W of electrical power over a 70mm x 20mm x 15mm heat load volume (aluminum). The ambient temperature is 25° C, the maximum temperature the heat sink can be is 40° C (ΔT = 15° C). Does...

Yes, I was just trying to supply an example guassian. The derived formula for FWHM is as follows, which you can solve for ##\sigma##. $$FWHM = 2\sqrt{2ln(2)}\sigma$$

Simply plugging this into software like MATLAB will present a solid guassian distrubution. However, my doubt comes from selecting the correct sigma. t = - 10 ns to + 10 ns ##\sigma## = 0.1 ns This produces a plot like so,

Thanks for the feedback. @hutchphd - Moving forward this is what I was truly trying to determine. Assuming I understand this correctly. I am trying to imagine what the output data would look like. Reading out the signal from the analog pin, would it give me 288 data points, where data[0] would...

I am looking at this Hamamatsu mini-spectrometer, C12880MA [https://www.hamamatsu.com/us/en/product/type/C12880MA/index.html] The specs are, Spectral response range: 340 to 850 nm Spectral resolution (FWHM) (typ.): 12 nm Number of total pixels: 288 pixels Now the size of the band of sensor...

I was thinking this past morning of the challenger explosion due to the stiff and cold failed O-rings in the fuel segments. I was trying to think of satellite failures, I couldn't find too much... Do you all know of satellite (components, instruments, etc) failures that occurred while in...

Good point, maybe I could turn it into a capstone or research credit. Thanks.

1. Right, this is the reason I mentioned state and local grants rather than large NSF/DOE grants. However, I am sure the length of the process is quite similar, if not worse! I am not too familiar with details of NSF, DOE, NIST, etc grants. I am under the impression they are large sums of money...

I am working on developing and building an Earth science related instrument, the instrument characterizes aerosols in the atmosphere. The instrument is for my master's thesis, at the Univ. of Maryland. I work full time and I am attending graduate school part-time. My company is funding the...

I have been working with some time series data of spectral signals, each wavelength has a different signal, so I normalize the data so I can plot it effectively. However, I am struggling to quantify the new normalized data. I will give an example below. Normalizing data often refers to...

Thanks for the feedback everyone :biggrin:

Hey friends, I have had some time on my hand due to the COVID-19 pandemic and I hope everyone at PF is doing well. Thus, I have been learning some introductory electronics. This may be more of an opioniated question but, I am curious to hear from some ~experts~. From my understanding, bare...

There is not, just the one I had laying around. I mean if we are talking bare minimum, I could just find a configuration that gets me 12 Watts. It’s a shame that the RPi is such an energy hog without any ability for sleep mode. I guess the Rasbian OS running in the background is the issue. Might...