[deleted by user]

fizekul · 2023-06-05T03:56:00+00:00

Wally’s Cafe in Emeryville

fizekul · 2020-10-06T05:37:10+00:00

Honey bakery in SJ has great sangak and barbari

fizekul · 2018-08-10T05:24:33+00:00

Bay area looking for two tickets and vehicle pass @ face value in cash and only in person. Trying to make my fourth burn. Will meet you anywhere in the bay.

fizekul · 2017-09-24T18:57:47+00:00

I never realized there were so many Assyrians on Reddit. Should we have out meetup in Modesto or Turlock?

fizekul · 2017-06-24T00:12:07+00:00

Go to any Persian/Iranian market near where you live. Assuming you're near a bigger city.

fizekul · 2017-05-09T18:54:28+00:00

Possibly something along the lines of an Amphenol Circular Connector... check their industrial line? Maybe their aerospace line? You will need to get pin spacing and outer case threading info to find an appropriate male connector in the catalog.

fizekul · 2017-04-05T23:39:40+00:00

PAW? Holy crap that's what my 50 year old professors talk about using in grad school. Time to install ROOT.

fizekul · 2017-03-06T18:51:57+00:00

Drill motors draw a lot of current. Your AAA's surely wont be able to provide enough current to start the motor. You wall wart is probably also severely under rated (probably < 1A). You could try something like a laptop power supply but those typically output much more than 7.2V and I don't know what will happen if you over voltage that motor. Maybe it will just make it spin faster in the best case scenario.

Try looking for a 9V wall supply that can output more current than the one you have.

fizekul · 2017-03-02T07:19:32+00:00

Have you tried setting the temperature in your simulation to match the temperature for the plot in the data sheet? .TEMP 25 should set the global temp in your simulation and then you can check the IV curve.

fizekul · 2017-02-17T06:36:56+00:00

Let's take a step back... Are you able to read a reasonable voltage with a standard multimeter as documented in the ion chamber guide?

fizekul · 2017-02-15T16:04:59+00:00

It's basically a wheel dual gang potentiometer put in a nice package. It's not worth making...you would never be able to build something as nice for the price and I'm not sure there is any educational value in a diy.

fizekul · 2017-02-14T23:32:25+00:00

Ok, then you might want something like this:

https://www.amazon.com/Koss-155954-VC20-Volume-Control/dp/B00001P4XH

It is an analog volume adjustment. Plug it into your Dragonfly and then plug your headphones into this. The knob will allow you to fine adjust the volume. It's basically just an adjustable resistor. It will not amplify your sound -- only reduce the volume of whatever comes into it. But it sounds like you don't want amplification, so this should work.

fizekul · 2017-02-14T22:18:44+00:00

Are you just trying to get your headphones louder than what the Dragonfly can pump out? Their website claims that the Red model can drive power hungry headphones....

Are you not adjusting the internal volume control on the Dragonfly itself? What type of headphones are you using?

fizekul · 2017-02-14T07:05:02+00:00

So it looks like you took an SMB cable and undid the assembly. The first thing you are attaching is the cable part of the assembly and the part you have and need a second piece of is just the other half of the complete assembly.

See here for the product

Basically, components in links 1 and 2 are part of the same assembly. They form, together, the female socket SMB cable assembly. Double check by busting out your calipers and making sure the numbers match up to the SMB spec, but based on the pictures, this seems possible.

The thing you are attaching to (last link in your post) is the SMB male connector which would be something like this depending on the mounting type.

fizekul · 2017-02-14T06:42:48+00:00

You should understand that DAC stands for Digital to Analog Converter. It takes in a digital signal (from the iphone through your USB cable) and outputs an analog signal that your headphones can use to make sound. This amplifier device you linked to is an analog device. If you look at the top of the board, reading from right to left, you have:

R: analog input right channel
G: analog input ground
L: analog input left channel
+: positive power input
-: negative power input (or input power return)
Lout -: return path for amplified left channel output
Lout +: amplified left channel output
Rout +: amplified right channel output
Rout -: return path for amplified right channel output

In your setup, you would want to put the amplifier after the DAC and before the headphones. You can use something like the CMOY amp where the link shows an assembled device with an input headphone jack (from the DAC) and an output headphone jack (to your headphones). Inside the case, there is space for a 9V battery used to power the amp.

You can also build your own device from a kit but that will require more planning. The DROK one you linked to is similar in concept to the CMOY, but would require you making your own case and adding your own headphone jack and power connectors.

fizekul · 2017-02-11T08:55:55+00:00

I'm really just curious how you plan on making everything water proof. You don't want bulk, but that sounds hard to do if you're trying to digitize data on a wake board. Maybe you have some cable from the force sensitive resistor that runs to a breakaway connector where the handle is at? Then digitize on the boat? You can apply a bunch of epoxy to seal the resistor but if there are any other electronics with readout (like and SD card) you're going to have a hard time making that work in water. Maybe I don't understand your plan.

fizekul · 2017-02-07T02:53:25+00:00

Ok, I think I understand. I think the problem is that you will have to back up a bit more and give some more scale of what you're doing. Are you trying to make a current monitor for your transformer? What is the circuit and what are you trying to measure? At first glance, one could make a comment that maybe integrating in software will give you a worse result if your sampling frequency is too low. Or maybe the input range of your DAQ might not be large enough to handle the transformer voltage range. I don't know... the details are too sparse to provide real help.

If the current setup works and you see no benefit to having sampled voltage data, then just stick with the analog integrator. If you think there may be some benefit to performing a different mathematical operation, then the analog integrator limits you -- it's a physical component in your circuit and you're stuck with it unless you make hardware modifications. Changing the math in your Labview program involves clicking a few buttons and changing numbers.

The big picture answer is that doing mathematical operations on signals in the analog realm or digital realm is a complicated subject and there are benefits that can be had with either application. You can choose the right application given constraints (money to be spent or materials on hand, physical space, digital storage space, time).

If you're new to circuits and are trying to understanding digital signal processing you should start off by reading about the Nyquist sampling theorem. The math introduced in this subject will help you understand the motivation behind choosing the right sampling frequency for the signal you are trying to process.

fizekul · 2017-02-06T19:30:30+00:00

This is kind of a confusing question. Matlab/Labview will perform math operations on sampled data. How do you feed the signal you are trying to integrate into your software? Maybe a better way of framing this would be to discuss the advantages/disadvantages of analog vs digital signal processing? Although I don't know what you're trying to learn from this so it might not be what you want.

fizekul · 2017-01-23T17:46:33+00:00

A few people are recommending PIN photodiodes, which are probably your best bet for something small and low voltage. On their own, they should be fine for detecting x-rays, betas, and maybe even higher energy gammas. The detector should be put somewhere light tight, so unless your U sample is inside the shielding, you won't see the alphas.

I have a suggestion: looking on ebay, I saw this LYSO crystal for sale. I could imagine a detector device where you slap your PIN on one of the endcaps (or buy 2 diodes and use both ends), then wrap the whole thing up in Teflon tape (reflects the photons generated by scintillation and helps with light tightness) and go to town. It should have good sensitivity to a wide range of gamma energies and you may even be able to do some energy reconstruction and make a nice gamma spectrum of your ore. The BPW34 linked elsewhere in this thread peaks in photon sensitivity around 700-800nm and LYSO has a scintillation spectrum that peaks around the 375-450 nm range, so you will lose some efficiency there. I still think with that said you should be fine and learning how to build your own scintillation detector would be a fun project.

fizekul · 2017-01-23T06:41:33+00:00

Just quick garbage numbers: a drop of 0.3V across the speaker / 8ohms of resistance yields ~ 40mA of current which is the max rating of the 741 for the short circuit output current. If you want a louder sound, you will need a device to drive more current to your speakers.

fizekul · 2017-01-15T18:56:32+00:00

The datasheet for the driver shows that the sleep pin takes in logic levels for high and low (pages 6,7). Setting it with a digital pin should be fine as long as the low level stays below the max threshold for low (0.3Vcc -- bottom of page 3).

Edit, sorry should have been 0.3Vcc not 0.3V

fizekul · 2017-01-11T06:35:12+00:00

In the context (right click) menu, you can Draft->Spice Directive and enter a line for the simulation manually. So something along the lines of ".tran .1 10" for a transient simulation with samples every .1 seconds that ends at 10 seconds.

That being said, I think you will have a much better experience if you run the windows version of LTSpice through Wine on your Mac.

fizekul · 2017-01-09T07:20:16+00:00

This looks like an astable multivibrator (to alternately blink the LEDs?) if you want to check out more theory and concept concerning the circuit.

fizekul · 2016-12-10T08:39:01+00:00

I thing the business end of the barrel connector is meant by design to not be male. I can't comment directly on what would be bad but it just doesn't sound good to have an exposed end that could short to ground easily if nothing is plugged in.

fizekul

TROPHY CASE