Recent Posts

1

ChatGPT/AI / Re: Introducing OpenAI o1

« Last post by SiliconWizard on Today at 11:01:29 pm »

That's surprising. Why they still call themselves "OpenAI" is beyond me.

2

General Technical Chat / Re: SPICE Generates nonsense with near-zero resistor values.

« Last post by Geoff-AU on Today at 11:00:18 pm »

Try

.option numdgt=15

Agreed.  But if that doesn't work try

.option nonsense=no

 

3

Thermal Imaging / Re: Ask for help from flir's official customer service for firmware. What if you don

« Last post by Geoff-AU on Today at 10:57:19 pm »

I had similar experience with my Flir One, the app has a slider for parallax correction and I asked that it be extended so I could work closer in to a PCB.  Their response was "no, go buy this device that costs 10x as much" (well outside my budget).

So I will never buy another FLIR device.

4

Test Equipment / Re: LCR Tweezer Fnirsi ST-1 versus Zoyi MD-1

« Last post by DaneLaw on Today at 10:55:42 pm »

I don't think I have tested either of them on diodes yet, It's kind of an uphill battle with 0.3v and 0.6v.

5

Beginners / Re: Data logger - separate power supply with isolation?

« Last post by thm_w on Today at 10:54:22 pm »

Having one isolator for I2C means all the RS485 connections are then common.
I guess you are planning to use something like SC18IM704PWJ which is not cheap.

But neither is 4x RS485 ISO chips, Si85853D-IS $4 each.
Plus Pi zero W only has one UART anyway.

Can you have all the RS485 devices on one bus? Or you think that is too risky.

6

Repair / Re: Agilent 34401A Bubble on PCB ... can it be saved ?

« Last post by The_Spectrum.A_idiot on Today at 10:52:22 pm »

Dear All

All the parts arrived ,

Now I would like your recommendation for the hot air station setup , how should I go hot and high output to remove the components fast ? or slow/ medium heat , medium flow and take my time and slowly ramp up the temperature until the solder liquefies ? Big , small nozzle ?

lastly I will kapton tape everything around that area and hope for the best , lots of flux , and hope for the best.

Let me know if you have any other tips and tricks how to deal with hot air .

Thank you in advance

7

Other Equipment & Products / Re: Ersa i-Con 'Nano' and 'Nano' Mk2 differences?

« Last post by analogix on Today at 10:51:42 pm »

I also got my Ersa Nano MK2 yesterday. Had Pico MK1 before, but decided to upgrade to the ESD version (nano) with the newer tips (142 series)
Also, it's made in Germany (vs the pico that was made in China)
It's too soon to share my experience, but considering how happy I was with pico, I think this would be even better.

Sounds great!
Please report back what your experiences are, when you're ready 

8

Projects, Designs, and Technical Stuff / Re: IGBT Linear operation

« Last post by Randy222 on Today at 10:49:11 pm »

But - Do we agree that continuous power dissipation is just that, no matter what?

Dissipating joules per sec means just that, but it in no way describes the temps.

Mount a TO220 high power metal film resistor to a huge heatsink and dissipate 100w, mount the same TO220 to a much smaller heatsink and dissipate 100w. The smaller one will be much hotter, including the TO220 package.

Watts just gives you an energy rate, how you sink out that energy is a bigger discussion/problem. As long as the sink is big enough to keep junction temp below max, for any application environment, then the package should survive.
The package itself is a thermal resistor, so for any given heatsink there will come a watts number where package temp gets too high. As example, TO220 in open air vs same in open air with a fan vs same mounted to large hunk of aluminum that is water chilled.
If the heatsink is very good (big water cooled, big fan cooled, etc) you can likely have the package dissipate more than rated watts, as long as the package temp does not go high enough to damage it. In real world there are limitations when it comes to physical heatsinks.

9

ChatGPT/AI / Re: Magic wire!

« Last post by thm_w on Today at 10:48:16 pm »

@Tooki,

It's puffery.  Anyone could say a light bulb works as designed without an electrical supply.  That is, it's not designed to produce light without electricity.  Yes, I find such puffery disgusting, but it is not inaccurate.  I once lost on a point in court where the company had stated a certain item was engineered to do something.  In fact, no licensed or even graduate engineer ever looked at the design.  The court considered that allowable puffery in the US.

This is a good thing, engineered is a word that simply means skillfully designed, it is not a protected term.
Sadly in Canada its the opposite.

10

Beginners / Re: Data logger - separate power supply with isolation?

« Last post by PGPG on Today at 10:48:05 pm »

I understand these 4 devices are powered from data logger and have no other connection to building earthing system. True?
If not true then you should consider isolation between them.

I would use microcontroller having 4 UARTs and one SPI and one more UART or SPI to communicate with Raspberry. if you want to isolate Raspberry from your own supply than you will have to isolate only one link.