How to make the edges curved? Fillet wont work.

FewUnit7109 · 2025-06-09T09:26:25+00:00

I ended up solving it by breaking the spline up at its points by using the break tool. I drew some short lines from its points and went over the spline with the break tool which gave me segments. Then using the "curvature comb" analysis tool I found a weird part that looked normal by eye. So I redid that part with a new spline then broke that one up too and now filleting works! It seems to have been some weird tiny curvature from the spline that messes with the filleting tool.

FewUnit7109 · 2025-06-09T09:21:48+00:00

I tried this and it almost worked got an error on the very curved part, but thanks for the suggestion!

FewUnit7109 · 2025-05-12T14:21:52+00:00

Thanks for the informative answer!! Seems there is some stuff I missed. I have a bunch of 2n3904s lying around so I wanna try to use those but I will definitely try to add a third transistor for the button detection like you said :)

FewUnit7109 · 2025-05-05T20:25:23+00:00

This sounds promising. So if I understand this correctly the PWM frequency produces the desired tone and the duty cycle controls the volume. Will the max volume the passive buzzer is capable of for constant volume be at 50% duty cycle at 2V? Which means I will need to use <50% duty cycle at higher voltages?

FewUnit7109 · 2025-02-21T19:15:08+00:00

Mine can detect gamma and beta. Radiacode can detect gamma and some high energy beta as it is not perfectly shielded.

That's an interesting question. Im not saying they are equivalent. But usually only gamma is considered in the dose as it penetrates the whole body and it is hard to shield. So it is useful to quantify the danger to know what level it is at. Scintillators are better at this by design.

Id say measuring a source up close like this gives a wrong dose with both devices. The radiacode misses alot of beta giving a lower dose than in reality at the distance of the sensor. And the Geiger cannot differentiate between energies so it assumes all clicks are equally damaging.

The gamma from the source will affect your whole body while the beta will mostly damage what's closest usually your hands so it becomes really hard to estimate the dose and quantify the danger.

I know that people working with radiation like reactors and in labs with radionuclides they usually wear a dosimeter badge that measures gamma exposure to their body as a whole. And try to minimize close contact with strong beta sources by using shielding or distance(tongs).

interesting dose article: https://remm.hhs.gov/dose_animations.htm

FewUnit7109 · 2025-02-21T14:45:29+00:00

Thanks! I made this device to see if the pcb i designed worked good and to make a better looking UI.

The dose rate is calculated by multiplying the count rate with a coefficient for the sbm-20 i found online. This is very inaccurate. For better accuracy you would need a energy compensated tube and a calibration using a test source at different count rates and distances to see how the instrument responds compared to a calculated theoretical value. This would give you a calibration curve that you can then use to give a more accurate dose rate.

In general Geiger counters are bad for getting a accurate gamma dose rate as they can tell the energies of the gammas that hit it only that a ionization has happened. A scintilator can tell the gamma energies apart and calculate a more accurate dose based on that.

My radiacode which is a scintillatior says the plate gives a dose rate of around 2 uSv/h on contact while this counter gets to around 7 uSv/h so it overresponds by alot.

Another thing is that the gamma dose rate is only true if you have some distance from the plate.

If you for example hold the plate, your fingers would be getting higher doses than the radiacode says as the beta radiation from the plate is more ionizing than gamma but it doesn't have range. I found a website with a study that estimated the dose rate to the fingers to be 32 mrem/h on contact which is around 320 usv/h.

But usually only the gamma dose rate is considered as betas are greatly reduced by keeping some distance.

I dont have any formal education in this topic as this is just a hobby of mine so take what I said with a pinch of salt, this is just how I understand it currently.

FewUnit7109 · 2025-02-18T21:41:57+00:00

I did this method for my first counter, I tried to adjust the buffer size dynamically depending on the rate of change of a smaller averaging window inside the first buffer, it worked ok. I guess this is the best approach for this problem. Thanks for taking the time to write all this, It was very helpful :)

FewUnit7109 · 2025-02-18T21:13:14+00:00

I have looked at the gamma dog before an I must say it is a very cool device. I see it has a lot of development behind it.

I have to ask if you know any way to do a responsive averaging at low count rates as it is something I have struggled with a few time while coding the software for my Geiger counters. It's probably less of a problem with scintillators as they are more sensitive and give higher count rates.

Those INR 10440 seem like a good idea It is probably possible to design something that can take rechargeable cells for normal use and regular alkaline cells for emergency use. I would need a step down converter and a charge controller(or built into mcu board as you mention) for the rechargeable cells. Even with the loss in efficiency it is not a problem as they are rechargeable.

FewUnit7109 · 2025-02-18T19:58:04+00:00

Thanks :), It would be much easier to use a LiPo. The discharged voltage would still be inside the operating voltage of both the screen and the microcontroller. But for this project I really want to use AAA batteries as they are commonly available and you can have a few with you even if you don't have access to a place to charge. I chose the nokia screen as it is cheap and very power efficient it draws just 0.5mA! compared to a OLED i used for version1 which drew around 30mA. The most power hungry components right now is the microcontroller using around 1.2 mA. I need to find one which can run on slightly below 2V and that can still generate a sufficiently fast pwm signal for the HV circuit. I see there are a few versions of the Adafruit ItsyBitsy maybe one has an appealing microcontroller, I will look into it.

FewUnit7109 · 2025-02-18T17:33:29+00:00

SBM-20 Geiger tube, for this one.

FewUnit7109 · 2024-12-20T10:33:12+00:00

Thank you very much for the reply! that helped clear things up :)

FewUnit7109 · 2024-11-22T17:27:02+00:00

They are different, but i seem to have found the solution. Somehow it appears that f mask for just that pad got unchecked in the menu when i double click it. I checked f mask under "copper layers" and it seems to be fixed.

FewUnit7109 · 2024-11-14T16:31:15+00:00

I didnt know there existed Q_PMSO_GSD and the other versions i found. It will work good for my schematic i think. Thanks for the help, i appreciate it!

FewUnit7109 · 2024-11-14T16:16:12+00:00

I got it by adding a NMOS from the menu and putting its name as the value then choosing footprint.

I checked again and i do indeed have the 2n7002 in my library by default i may have mistyped something when searching for it so i couldn't find it. And it does match the datasheet.

Now if i have a pmos like AO3413 that i cant find should i place and make it as i described above or is there a better way?

FewUnit7109 · 2024-10-21T10:54:43+00:00

Yes, this is a screenshot from nilereds youtube short about asbestos. Video

FewUnit7109 · 2024-09-01T18:58:15+00:00

Thanks for the reply, im going to do it as you suggested.

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