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Mini , 06-04-2024, 11:25 PM

And yes I would buy lowest 4 channel scope and "hack" it. Whatever series you like.

Gagan , 06-04-2024, 11:25 PM

sure

Gagan , 06-04-2024, 11:29 PM

what about power supplies, the one i told you i used in college had two dc output of both 1 A max output current, both the supplies were +ve with respect to ground, I used to make virtual ground for my BJT or MOSFETs to work, now as i am getting for my own there are plenty of options in linear power supply, there has been one with +ve and -ve both supplies, with them I had two +ve power supplies that i used to combine in series to get higher output, now would that be possible with -ve one or not, which one should i consider or would be good

Mini , 06-04-2024, 11:30 PM

Which one have -ve? Can you give me a link?

Mini , 06-04-2024, 11:35 PM

But I would of course buy at least 2 channel, but both channels should be totally separate. That -ve seems like they one common ground. I wouldn't buy such a power supply. I want two totally separated channels. Both channels having their own transformer, no common point.

Mini , 06-04-2024, 11:37 PM

I have at work very cheap linear power supply. TENMA 72-10495. It costs 200 euros on farnell.

Mini , 06-04-2024, 11:38 PM

You can buy also simply 2 separate one channel linear power supplies. It's same. Whatever you can find cheaper.

Mini , 06-04-2024, 11:39 PM

And I think you overthink too much again. Buy any cheap linear power supply and it will be fine.

Gagan , 06-04-2024, 11:43 PM

https://www.valuetronics.com/product/e36311a-keysight-technologies-dc-power-supply-new this is the one that has 3 outputs ,+25 to 0,-25 to 0 and 0 to 6 volts

Then there is this one https://www.testequity.com/product/12379-1-E3630A?gad_source=1&gclid=Cj0KCQjw9vqyBhCKARIsAIIcLMH8pGT552ieg1XtAkPh5ahlYWbz94wMSQDICRPv4pa3yH5k1NiwXR0aArPKEALw_wcB

Gagan , 06-04-2024, 11:45 PM

I will buy the cheaper one for sure, they are really expensive but its for reference

Mini , 06-04-2024, 11:47 PM

E36311A is interesting. It says:
Output 1: 0 to 6 V, 0 to 5 A
Output 2: 0 to +25 V, 0 to 1 A
Output 3: 0 to -25 V, 0 to 1 A

Mini , 06-04-2024, 11:49 PM

I think output 2 and 3 have common ground. Otherwise why write 0 to -25V. If you have access to one you can measure it.

Gagan , 06-04-2024, 11:49 PM

Nice catch

Gagan , 06-04-2024, 11:50 PM

Unfortunately i don't have access to E36311A, but how one could get to know about it

Mini , 06-04-2024, 11:51 PM

They are fine too, it all depends how you connect it. Everything is relative. But I wouldn't still buy one like that. Sometimes when you connect two separate circuits you may see something weird. Like think if you connect USB to these devices... etc.

Mini , 06-04-2024, 11:54 PM

You should see same voltage relative to each GND. Also try to measure resistance between each GND. Unless GND have some sort of electronics in series like relays then should show 0 ohm. Anyway that's not important. Pick one with 2 separate channels.

Gagan , 06-05-2024, 12:29 AM

Sure, thank you for feedback

Gagan , 06-05-2024, 12:32 AM

I believe that if they have same ground and share same transformer, then reading voltage reading by multimeter by connecting black lead to 0 and red lead +25 would give me 25 volts on multimeter and if i will connect the black to -25 and red to 0 would still give me +25 reading on multimeter but if it would be separate it would read -25

Mini , 06-05-2024, 07:09 AM

Yes you are correct about first part, but your last sentence isn't correct. If you have two separate outputs isolated from each other meaning each channel has their own transformer then you can't see anything, you don't have common reference point. Think about it like you have 2 different batteries. If you put one multimeter probe to one battery and another to other(either + or -) do you see any voltage(without batteries touching each other)?

Gagan , 06-05-2024, 10:31 AM

I got it i would not see any potential difference between two of them until or unless i do not connect the other end end of them to each other, which if not put any load between them would create a short circuit, lol, i had this in my mind but then I was like how come I could measure it in the one I had in lab, i think its cause they have common ground

QDrives , 06-05-2024, 07:13 PM

Both the DHO and MSO have advantages and disadvantages compared to the other.
MSO5000 is 8 bit, DHO is 12bit
MSO5000 has a fan, DHO does not

For most other specs, I think it is like having a 1Ghz scope to measure I2C communication at 100kHz. However, you may just have the application that requires that spec.
Do note that the DHO900 can be up to 250MHz and MSO5000 up to 350MHz so bandwidth wise it is not that far apart.

QDrives , 06-05-2024, 07:16 PM

"*Logic Analyzer on scope is quite pointless* -- No it is not. What are you analyzing? The (quality) of the signal (and errors)? or to see that you are sending messages? If you need to capture many packets, you are not designing your software right.
"*You need external "device" for MSO5000 series.* -- No you don't. Logic analysis can be done with the analog inputs. You do not need the 16 channel digital interface.

QDrives , 06-05-2024, 07:18 PM

As far as I know, no scope has active probes. However, if you mean dedicated communication between scope and probe, then no MSO5000 does not have those.

QDrives , 06-05-2024, 07:42 PM

Are you happy with that Tenma power supply?
The problem I have with it is that the datasheet itself does not mention "linear". It does state 9.1kg which would make sense for a 300W linear power supply.
A Tenma power supply that I worked with did not last over 2 years and during a voltage change, the output spiked to 80V (when changing from ~4V -> 6V). You can imaging that most logic would be destroyed with such high voltage.

Mini , 06-05-2024, 09:34 PM

I have written several times that you use scope for signal integrity. And yes of course you can analyze communication on analog inputs. I was talking about logic analyzer inputs. I have used analog inputs for SPI and I2C. But it's pretty useless, you can see only so much you fit on the screen. Again - there are logic analyzers for that. And power of logic analyzer lies in the software what scope don't have. I have Saleae logic analyzer and it makes my life so much easier. I usually never bother to fire up Rigol when having issues. I have had few times signal integrity issues when using cheap chinese wires, but that's about it.

Mini , 06-05-2024, 09:39 PM

I'm using that Tenma in my other workplace. We have multiple units of them. And they are very good for that money in my opinion. We have had them like 5-10 years or so, no problems so far. They are linear power supplies. Tenma seems to be copy of Korad. You can buy Korad if you want. I have no idea why or how you had problems with it, we have 0 problems like in 5-10 years. And we use it every day.

Mini , 06-05-2024, 09:48 PM

And btw you never know when you need more channels. Other day I did need more than 8 channels. Was trying to reverse engineer something. But mostly indeed 4 is enough for SPI and only 2 for I2C. Also maybe you need multiple channels at the same time. You never know. Or if you happen to debug paralleel bus.

Gagan , 06-05-2024, 10:30 PM

Hi mini, I have decided to go with the DHO series and I am just figuring out which power supply I will need, although there are good power supplies from keysight, but gosh the isolated one cost $2400 CAD, from Tequipments( A distributor) I could get the E3620A for $1100 but it is way outdated, it does not have any features rather than providing basic power supply https://www.keysight.com/ca/en/product/E3620A/50w-dual-output-power-supply-two-25v-1a.html now this comes with a price of around $1500 CAD, Keysight is going to discontinue this version and the new version that they have replaced this with is E36300 series, the E36311A is having +25 volt and -25 volt on both output but they share the same common ground, lol. https://www.keysight.com/ca/en/product/E36311A/80w-triple-output-power-supply-6v-5a-25v-1a.html It comes with a price of $2000 CAD I can't believe that decent power supply having separate electrically isolated supply doesn't come within a cost of $2k, the one they have the isolated outputs is E36312A which have so many features that I guess I do not need https://www.keysight.com/ca/en/product/E36312A/80w-triple-output-power-supply-6v-5a-2x-25v-1a.html Power Output: 80W
DC output:
One: 0 to 6V, 0 to 5A
Two: 0 to 25V, 0 to 1A
Three: 0 to 25V, 0 to 1A
4.3-inch color LCD display
Color-coded channels
Individual knobs for voltage and current
USB/LAN
Digital I/O port
Individual on/off on all channels
Electrically isolated channels
Front and rear output terminals
Data Logging
Output Sequencing
Output LIST
Auto series/parallel connections
2-wire or 4-wire remote sense
Over Voltage, Over Current and Over Temp Protection
Includes BV0003B Power Supply app

there are some features that are really useful like remote sensing, individual on/off on all channels, USB option, preset of voltage and current option, but most of them I dont think I need.
Image Now, there is Keithley 2231A-30-3 which comes with a decent price range of around $1300 which seems pretty good

Gagan , 06-05-2024, 10:30 PM

https://download.tek.com/datasheet/2231A-30-3_Datasheet_1KW-61078-0.pdf

Gagan , 06-05-2024, 10:31 PM

https://www.tequipment.net/Keithley/2231A-30-3/DC-Power-Supplies/Lab-Power-Supplies/?Source=googleshopping&gad_source=1&gclid=CjwKCAjwmYCzBhA6EiwAxFwfgA44mBF5htinYNUnryQYJOpCU2UcPa-SULo2dudaIFpaTGF5OGCbFxoCfZ0QAvD_BwE

Gagan , 06-05-2024, 10:31 PM

What are your thoughts on Keithley PSU?

Gagan , 06-05-2024, 10:34 PM

Gagan , 06-05-2024, 10:37 PM

Gagan , 06-05-2024, 10:37 PM

this one is from its datasheet

Gagan , 06-05-2024, 10:39 PM

@QDrives what is your point of view

Gagan , 06-05-2024, 10:43 PM

it is was launched around more than 8 years ago, but if it is reliable, who cares

QDrives , 06-06-2024, 04:06 PM

If you want top of the line power supplies you can also have a look at https://www.delta-elektronika.nl/
They pride themselves for making good quality power supplies.
I have not worked with Keithley, but I cannot imagine they would be bad.
I use the Siglent SPD3303X-E. It is acceptable, but at least also programmable. Used it together with the MSO5000 to do automated DC bias testing of capacitors.
The cheaper Delta-elektronika power supplies are not programmable without extension.

QDrives , 06-06-2024, 04:08 PM

As long as it is produced recently. There maybe an update coming - now with a fancy LCD color display.

Gagan , 06-06-2024, 04:08 PM

thank you @QDrives I am gonna look at it

Mini , 06-06-2024, 10:44 PM

To me they all look pointless expensive piece of gear. I'm sure they are good, but you are just starting. Buy any cheap linear power supply with 2 channels and that's it. Why spend 1-2k on power supply.

Gagan , 06-07-2024, 06:54 PM

which one would you recommend, I had been through a lot of reviews for power supply, especially linear one, they all have some sort of issues, makes it hard for me to choose

Mini , 06-07-2024, 09:19 PM

Buy any linear power supply. I can recommend this Tenma. I have had no issues with it in the past 5-10 years. Korad is very decent brand. I think Tenma is copy of Korad.

Gagan , 06-07-2024, 09:21 PM

What typical model number of korad or tenma ?

Mini , 06-07-2024, 09:21 PM

I would put extra money on microscope. Buy better optics for you money. That's where I would put my money. Decent microscopes are really expensive. Or buy some good multimeter.

Mini , 06-07-2024, 09:22 PM

I gave you Tenma link. Exact model doesn't really matter. Buy anything that you like.

Gagan , 06-07-2024, 09:24 PM

A have good multimeter but have to look for a scope, I would look for it when ill buy my all stuff and whatever the remaining budget will be. Ill have a look at your link

Mini , 06-07-2024, 09:25 PM

Sorry, I didn't give you a link because i don't know your distributors. I gave you model number. TENMA 72-10495

Mini , 06-07-2024, 09:30 PM

What multimeter do you have? Microscope is must. I suggest to prioritize microscope over power supply for example. The thing is microscope lasts forever if you take good care of it. It's pure optics.

Gagan , 06-10-2024, 12:33 PM

Hi Mini, sorry for replying late, I have been using ABRA Multimeter, I do not know how often I would be doing soldering maybe a lot maybe not much/ would be using breadboard most of the time , thats why I wanted to purchase at the end, according to the need and bidget

Mini , 06-10-2024, 05:12 PM

if you are going to do breadboard stuff, any tools will fit. Any scope, any multimeter etc.