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I've developed a similar software in Python. It utilizes an ancient 6632A as the power supply unit and another dated 66332A as the electronic load. Utilizing GPIO enhances the testing speed. In this instance, I'm examining the TPS 61088 module (3.6V to 12V) and a MI car charger (12V to 5V).





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Metrology / Re: LM399 based 10 V reference
« Last post by Birb on Today at 05:36:02 am »
Hi, here's an attempt at designing a lm399 based Vref. Note that the OP077 will probably be replaced with something else and is currently a placeholder.
Also, the input voltage is 15V, which gets regulated by an LM7812, giving sufficient headroom for a lower noise.
Lastly, the entire reference section should be heated by a small PTC heater to around 50C. It should be good enough to keep the resistors more stable (Using weird BWL resistors - they seem to be ok, but I don't trust the tempco).
Though I worry that the buffer may not be sufficient?
Any feedback is appreciated, thanks a lot.
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The two integrators are just acting as a second order low pass filter, you can do that easily with just a single opamp:
https://webench.ti.com/filter-design-tool/filter-response
I tried a few Sallen-Key type filters but they provided distorted sine waves at the amplitude I need so I went with the dual integrators instead which provides the nicely shaped sine waves you see in the attached photos, not the sort of integrator/sharply-peaked sine waves of the dual low pass filters with single op-amp.
Thanks for the design link. Maybe I missed something. I'll give the 2nd order filters another try.....  :-/O
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4)  Amplitude stability to 0.5% is very important. It is entirely dependent on the +/- rail voltages so the need for input voltage regulation is critical.
That's true only of the square wave.
You might like to ponder what parts affect the sine wave amplitude precision.
Thanks for your comment but it doesn't address my concerns at all. I appreciate your hypothesizing but I don't solve my problems by "pondering". I chose my parts by design and for the reasons I stated in my OP.
Maybe we have a "language barrier" situation here.
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This is a duplicate of your earlier thread :
https://www.eevblog.com/forum/projects/make-it-better-sine-wave-generator/msg5394134/#msg5394134
NO, it is NOT a duplicate of the earlier thread. If you had actually read what I have said in this thread you would realize that it is a new circuit and a new set of questions, etc.
Thank you.
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General Technical Chat / Re: Custom "R-core" transformers on ebay
« Last post by SiliconWizard on Today at 05:16:24 am »
I would like a transformer built on a monohedron.
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Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's
« Last post by eTobey on Today at 05:15:41 am »
Your posts are slightly offtopic...
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I had the scope a few years ago and am no longer quite up to date:
Is it still the case that you have to renew the hack as soon as you load new firmware onto the scope?
If so, then nothing has changed in the last 5 years...

Hey Martin,

yes, you still have to use the patch after every update.
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Maybe some short but wide light pipes?  They will diffuse the light, but longer will likely be better.
Look for a part like Bivar PLP5.  These can be found on Digikey, but also cheaper copies on AliExpress.

e.g. https://www.aliexpress.com/item/32962156618.html
I've used some 19mm long 3mm diameter light pipes from this seller, and mount them in a 3D printed holder to help alignment and reduce bleed.
I also 3D printed a jig for drilling the front panel holes in the plastic enclosure.  Marking and center punching alone lead to noticeably poor alignment, and I was too lazy to build a jig for the CNC.
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Test Equipment / Re: Siglent SDS2000X Plus
« Last post by MathWizard on Today at 04:48:57 am »
OK the scope can decode some stuff, so it's working at least.

Could this be SIO (Serial Input Output) or SSP (SPI) (Synchronous Serial Port (Serial Peripheral Interface))

On the VFD IC,
Yellow is on p17-SIO chip select input
Red = p15-Serial data output
Blue = p16-Serial clock I/O
Green = p14-Serial data input

So maybe red is some MISO and grn is MOSI ?

As far as I can see, if CH3 is the clock, nothing changes on it's rising edges. But red/grn do change to any state, and seem to start changing exactly when blu starts falling low. There's 8 low points, and 7 high points, but it's pulled high, so that could be 8 highs or 9.

In the link below, their example of SIO, it looks like the data is read on the falling edges of the CLK, so the opposite of mine here.

https://toshiba.semicon-storage.com/us/semiconductor/knowledge/e-learning/village/seven-serial-interfaces-of-toshiba-mcu.html

It should be this block diagram in the VFD IC
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