Recent Posts

1

FPGA / Re: Help on translate schematics to Verilog.

« Last post by caius on Today at 07:18:25 am »

Thanks for reply.Is the tristate buffer of my picture with inverted output?All other images on the net have no circle on the output (like the attached image, it's the Quartus primitive)

2

Beginners / Re: How Current Limitation is happening in the circuit???

« Last post by ommsiva on Today at 07:17:37 am »

Hello All,

I started constructing prototype of the below circuit, But 68ohm,2Watts resistance went to breakdown.
again i changed to 470ohm,2Watts , again it started smoking.


I also changed the MJE2955, but 470 ohm started smoking, What is the problem in the circuit?

Thank you all.

3

Beginners / Re: Checking for noise in resistors

« Last post by Calambres on Today at 07:12:49 am »

I think most of you are getting me wrong. I know about replacing the resistors for better ones, I already said that as well as I said that I'm just courious about the possibility to have a noise testing circuit. I'm sure there should be some designs out there. I'm aware of an old Heatkit tube signal tracer that can perform noise testing in components but such gear is almost impossible to get here in Europe, at least at a reasonable price.

Anyone know of some noise testing circuits out there? I'm sure there must be some around...

4

Beginners / Re: Checking for noise in resistors

« Last post by coppercone2 on Today at 07:06:33 am »

1) plug in good resistor to current source
2) measure ACV
3) compare with bad resistor of similar value
4) amplifier may be required


you measure noise with the AC volts function of a multimeter

5

Test Equipment / Re: TinySA Ultra launched

« Last post by shapirus on Today at 07:04:58 am »

I vote @shapirus reports the bug, he found it, I was just confirming it.

Not via google groups, sorry. Not gonna go through the associated setup hassle.

But since the author is registered on this forum, let's mention him.

@erikka , do you consider this one a bug, a glitch, or a feature? :)

6

Microcontrollers / Re: SD Card reliability in SPI mode

« Last post by abyrvalg on Today at 07:04:07 am »

Also, check “industrial grade” sd cards. “Industrial” in their case is not just about wider operating temperature range, but also adds more robust internal algos and better memory types (MLC or even SLC in some smaller models).

7

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by ebastler on Today at 07:03:55 am »

BTW, it's better to keep decompiled sources in git rather than an assembled .apk

It's an interesting question what Rigol will think and possibly do about this. Hosting copies of their copyrighted binaries on a public server is probably violating license terms already. Hosting and sharing decompiled sources might be beyond their pain threshold?

Or maybe they don't care. Who is brave enough to run the experiment? 

You may not resell, decompile, reverse engineer, disassemble, or otherwise convert the Software to a human perceivable form.

https://int.rigol.com/announce/terms

8

Beginners / Re: Checking for noise in resistors

« Last post by Vovk_Z on Today at 07:00:11 am »

Who said that noise is a good thing in tube amps?
You are probably confused by advocates of single-ended amplifiers who like the even-order distortion from the circuit.

Noise is like a natural disering to digital signal. With added some grain of noise and some grain of even harmonics makes tube sound what it is.

9

Repair / Re: Desoldering advice

« Last post by shapirus on Today at 06:59:36 am »

Given my next attempt will be with a much larger soldering tip and using preheating, what would be better, adding regular solder to transfer and hold the heat or trying more low MP alloy?

It depends if anything in that area of the board is expected to get hot during normal operation. If it is so, then I would only use low-melt solder when there's still not enough heat transfer for the regular solder to melt. The remaining traces of bismuth can potentially lower the melting point of the post-repair joints enough to cause reliability issues if they get hot enough.

10

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by shapirus on Today at 06:54:10 am »

Damn that's great. It will be a crime not to share

BTW, it's better to keep decompiled sources in git rather than an assembled .apk -- for the very purpose of VCS, that is, to keep history, to be able to see diffs, to be able to cooperate with others via forks and pull requests.

Please consider this.