Recent Posts

91

Test Equipment / Re: Siglent SDS800X HD Review & Demonstration Thread

« Last post by mawyatt on Today at 01:37:47 pm »

Ouch   The sweeping methodology sounds painful.

Not so bad if you have Grad Students do all the work


"Indeed it is. The other thing that I think often gets overlooked is spurious emissions (spurs) generated within the instrument itself."

Agree, spurs are bad in any instrument, especially SA, however since these DSO are being utilized as a low frequency SA they are particularly bad here as with SA.

The absolute levels being shown and discussed are remarkable for any DSO much less at this price point, and this low level begins to reveal all that's underneath the Time Domain noise floor that's generally not viewable with typical scope usage!!

Best,

92

Power/Renewable Energy/EV's / Re: Flyback controller output voltage and amps under load

« Last post by Faringdon on Today at 01:36:31 pm »

You say you have 3uF on the primary DC bus?
As Xavier already states, 3uF is nowhere near enough.

Your sim is now attached and working....you have chose very deep CCM....so maybe look into SiC sec diode. Or just make it more near to DCM
You chose bias winding reg...so will not be that accurate over the load range.
In the sim, you need to add the resistances of caps and L's

As you know, you chose K1=1, so no leakage, that will need adding in but i sure you know this

You also need to pick  component type and P/N...not just have the generic diode. I had to change your diodes as i did not have them in mine.
Be sure to choose ultra fsat diodes where needed.

93

Test Equipment / Re: Siglent SDS800X HD Review & Demonstration Thread

« Last post by 2N3055 on Today at 01:34:30 pm »

Hello,

If I understand correctly, the combined signal is fed into C1 and the FFT would already show the interference of the input circuit and the ADC.

Best regards
egonotto

Yes

However one must be careful when combining the signals to not introduce IMD due to interaction between the two signal sources before they enter the DUT, usually at smaller levels and with sufficient source isolation (>6dB) this isn't an issue.

Best,

Maybe of interest is some AWGs have the ability to "combine" the 2 channels internally, this could be done in "Digital Domain" before the DACs and channel amps/attenuators, or after the DACs in the "Analog Domain".

Each would have advantages/disadvantages but both techniques could introduce IMD! Even in the "Digital Domain" combining since the combined digital summed signal then undergoes Digital to Analog conversion and subsequent amplification/attenuation before reaching the AWG output.

Best,

And what I have shown was exactly that: digital Channel Combine in SDG6000X.
It is not as good as it would be with good resistive combiner, but plenty good enough for many uses.
All you need to know and be aware of is what are the limits...

94

Test Equipment / Re: DSOX2000 and 3000 series - licence , have anyone tried to hack that scope ?

« Last post by calvinlove0 on Today at 01:33:38 pm »

....dumb question...do you still have that .cab file? :3 need v2.35 to fix my scope

95

Repair / Re: Foaming electronics-safe spray cleaner

« Last post by Alex Eisenhut on Today at 01:29:42 pm »

I was hoping to make cleaning my vintage smoker's CRT a bit easier, everything's covered in dusty greasy stuff. Even the screws that keep the case together have brown heads...

96

Microcontrollers / Re: SD Card reliability in SPI mode

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

Years ago SD card failures here on industrial embedded, were solved  by changing to :
Amtron or Apro Industrial grade SLC ( Single Level Cell Nand)
The capacity is limited to 32GB.
Data sheets typically show MTBF of 3 million hour and 60000 erasures. -40 ~85C,  5 year warranty
 https://www.amtron.com/sd_card.htm

97

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by Mechatrommer on Today at 01:28:42 pm »

i wonder why sds800x is not capable 500MSps CH1,CH2 and 1GSps CH3 (CH4 off) since it has 2x 1GSps ADCs, correct?

98

Test Equipment / Re: Siglent SDS800X HD Review & Demonstration Thread

« Last post by mawyatt on Today at 01:25:32 pm »

Hello,

If I understand correctly, the combined signal is fed into C1 and the FFT would already show the interference of the input circuit and the ADC.

Best regards
egonotto

Yes

However one must be careful when combining the signals to not introduce IMD due to interaction between the two signal sources before they enter the DUT, usually at smaller levels and with sufficient source isolation (>6dB) this isn't an issue.

Best,

Maybe of interest is some AWGs have the ability to "combine" the 2 channels internally, this could be done in "Digital Domain" before the DACs and channel amps/attenuators, or after the DACs in the "Analog Domain".

Each would have advantages/disadvantages but both techniques could introduce IMD! Even in the "Digital Domain" combining since the combined digital summed signal then undergoes Digital to Analog conversion and subsequent amplification/attenuation before reaching the AWG output.

Best,

99

Projects, Designs, and Technical Stuff / Re: Vacuum Fluorescent Display Driver

« Last post by bostonman on Today at 01:24:59 pm »

I may have been confused about the CD-1848P. I thought this was a DC/DC converter, however, yesterday I removed the board and it looks like a transformer. Underneath the silscreen reads 'trans', I saw magnetic wire, and it looked like multiple windings.

The transistor (NEC C2334) that gets hot (next to the CD-1848P) had two pins with low resistance, but, after removing the board from the main PCB, the transistor measures normal; I'm assuming the low resistance is due to connections through the transformer windings that are made when the board is soldered onto the main PCB.

Yesterday I measured all the pins on the new 518 and didn't find any shorts. At this point I plan to remove this chip, power the unit, and see if the 34v 38V returns to normal.

Seems hard to believe I got a bad batch of ICs, but I guess it's possible. I'm considering buying a socket rather than soldering another IC onto the board, but one capacitor may be in the way, and it's also a week of waiting for them to arrive from DigiKey.

100

Buy/Sell/Wanted / Re: FS (EU/WorldWide) Logic analyser Hantek LA5034

« Last post by coromonadalix on Today at 01:20:39 pm »

software still available from hantek 

https://www.hantek.com/Product/LA5034/LA5034_Software.zip

https://www.hantek.com/Product/LA5034/LA5034_Driver.zip