Recent Posts

1

Projects, Designs, and Technical Stuff / Re: (Yet Another) DIY Multislope ADC

« Last post by iMo on Today at 07:34:05 am »

Here is the excel table you may play with v1.0.
If you may find an issue pls do report..

2

General Technical Chat / Re: Cable Management

« Last post by nfmax on Today at 07:33:10 am »

Each individual cable loosely coiled inside a ziplock bag, with a descriptive label on a card insert. All the bags stacked filing cabinet style (on edge) so the labels are visible, in a drawer. Apart from mains leads, which breed when you don’t look at them.

3

Repair / Re: Simpson 260 series 6 repair

« Last post by wasedadoc on Today at 07:24:36 am »

How do you know that the 50uA current source is 50uA?

4

Projects, Designs, and Technical Stuff / Re: Heated Ferrite == Useless Ferrite

« Last post by Ian.M on Today at 07:22:20 am »

To avoid confusion, the 'airgap' doesn't usually contain air! Except for cores gapped by grinding the center limb, its more usual for the gap to be filled with an insulator of some sort to provide the required spacing.

Additionally, the core may be gapped by mixing a small percentage of tiny glass spheres into the glue, with the size of the spheres chosen for the required gap.   It can be extremely difficult to distinguish between a core gapped this way, and an ordinary glue line.   

Unless you measure the outside dimension of the core, across the glue line or gap, with a micrometer (after removing tape etc. and cleaning the exterior surfaces) before disassembly, and measure again after reassembly, you wont know how accurately you have re-established the original core gap (or lack thereof).

5

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)

6

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.

7

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...

8

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

9

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? :)

10

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).