Recent Posts

1

Test Equipment / Re: Rigol DG800 Combining waveform with arbitrary waveform

« Last post by thm_w on Today at 09:26:08 pm »

As mentioned in the manual:
- Tap the Channel desired in the bottom left of the screen
- Select CombineSet to On
- Choose your waveform to combine with, settings desired, etc.
- This function is only valid for the basic waveforms.

- check
- check
- check... wait i cant choose the arb waveform. Its just the on i have used before.

The manual is from July 2018, which is also the one i have found.

You understand this part right? "This function is only valid for the basic waveforms."
If you want Arb then set your channel 1 as the Arb waveform and combine with something else (square, sine, etc.) shown here:


If you want Arb with Arb, then you'll combine channel 1 and channel 2.

2

General Technical Chat / Re: What ICs are used in this rocket?

« Last post by SiliconWizard on Today at 09:24:45 pm »

I think the OP is trying to get into the space industry, and of course trying to figure out why China is gonna win this industry as well as with power supplies.

3

Test Equipment / Re: Magnova oscilloscope

« Last post by mk_ on Today at 09:24:40 pm »

I'm also intrigued by the probe interface, particularly the potential for Batronix to develop their own active probes in the future. It's something I'll definitely keep an eye on.

Here the same and at the same time a very important point:
I cannot imagine that it is "forbidden" to be able to use active probes from other manufacturers.
We, for example, have only bought Lecroy scopes for decades because we have their Probus probes/current clamps and they would not be usable otherwise.
If I were Batronix, I would not necessarily invest energy in designing my own active probes, but instead in appropriate adapters for "third-party" probes.
The electrical part of such an adapter is easy to make, the compatibility is created in the software, which would have to be maintained accordingly.
I consider this to be a purchase reason that should not be underestimated if companies could continue to use their existing (expensive) probes.

there has been a discussion with Batronix and I assume that they are open for some related discussions about the I2C-protocoll to the probes for reducing somehow this bottleneck. As an example: ntcnicos diffprobes with an batronix-adapter could be an interessting solution for that chicken/egg problem...

4

General Technical Chat / Re: Know of any good books/sources of useful electronic schematics?

« Last post by Benta on Today at 09:24:03 pm »

If you're in the "beginner/intermediate" stage, Don Lancaster's "Cookbooks" are a good place to go.
They are free online:
https://www.tinaja.com/ebksamp1.shtml

5

Manufacturing & Assembly / Re: Metcal MX-5210 underwhelming performance

« Last post by armandine2 on Today at 09:23:23 pm »

Hi!

I I bought Metcal MX-5210 and a wide range of original tips.

I bought the bigger Metcal after using the smaller for a few years, and I was expecting more too.
Maybe it is the tips - given these actually set the temp.

6

Metrology / Re: DIY 0.1 to 10Hz Noise Amplifier

« Last post by trtr6842 on Today at 09:20:36 pm »

Linear phase shift, each frequency's starting phase is evenly spread out over 360°, Vpp = 16.9x the base amplitude, which feels pretty good considering there are 70 tones added together.

Do you really mean peak-to-peak, and not peak? And "base amplitude" means just the (single-sided) peak amplitude of the sine?
Then 16.9 would imply a crest factor of 16.9/2/(sqrt(0.5)*sqrt(70)) = 1.4283, which would very good for the sum (a single sine wave already has crest factor sqrt(2)).

If you mean this value, then it would be only approx peak, not peak-to-peak.

Code: [Select]

# print('peak: %.3f' % (max(y)/2-min(y)/2))

Thanks for sharing your results!

To try and clarify, when I said "Vpp=16.9x the base signal amplitude", I was incorrect, thanks for catching that!. I actually calculated the Vpp of the end signal and divided it by the Vpp of a single tone.  Each tone is calculated as sin(2*pi*N), so the amplitude is 1.0, and Vpp would be 2.0.  So that value would be same as the overall single-ended amplitude divided by the single-tone single-ended amplitude (what a tongue twister!)

So for crest factor, I think the actual with the linear-phase method is 2.853.  I added this code at the end of my script, after the normalization (which doesn't affect crest factor):

Code: [Select]

        vpp = (max(y) - min(y))
        vp = vpp/2
        ac_rms = np.std(y) # AC rms and standard deviation are mathematically equivalent
       
        print('peak to peak: %.3f' % vpp)
        print('peak (SE): %.3f' % vp)
        print('std-dev (AC RMS): %.3f' % ac_rms)
        print('Crest Factor: %.3f' % (vp/ac_rms))
and I got:

peak to peak: 2.000
peak (SE): 1.000
std-dev (AC RMS): 0.350
Crest Factor: 2.853

So your iterative phase guessing is about 35% (2.6dB) better.  I'm curious if that would make a noticeable difference, I'm not sure.  How quickly does your example script run for the 10kpt 1000 iteration script you shared?

7

Buy/Sell/Wanted / Re: FS: Tektronix SC502 98% working

« Last post by BlownUpCapacitor on Today at 09:18:06 pm »

I might add that the serial number is B021284. It was a former unit from SCC, a local community college.

8

FPGA / Re: Help on translate schematics to Verilog.

« Last post by xvr on Today at 09:15:16 pm »

A lot of generated clocks, as BrainHG say. In this form it will not work. You need to recreate all RTL based on logic of original schema, but made if fully synchronous. You can use PLL to boost original 8MHz clock to some high frequency clock to have a room for maneuvers, it definitely will help (ratio of speed of original circuit and speed of MAX FPGA will allow using of a LOT of ticks to implement logic that originally would be fit in one tick).
But it is not an easy task.

Alternatively you can try implement original schema, using low level primitives of FPGA and disabling optimization in synthesizer, but it quite hard and do not grantee result  Timing of FPGA primitives is different from timing of original logic.

9

General Technical Chat / Re: Know of any good books/sources of useful electronic schematics?

« Last post by themadhippy on Today at 09:13:24 pm »

Another magazine online:

https://www.worldradiohistory.com/UK/Hobby-Electronics/

if you go to the home page https://www.worldradiohistory.com/index.htm you can find hundreds of other useful  magazine and books

10

Repair / Re: TDS3014 adventures

« Last post by Jarek on Today at 09:13:10 pm »

Does anyone know if pin 18 of DS1742W (CE)
is connected to one of the pins of the 100-pin connector,
if so, with which one?