$200 power supply: New KORAD or used HP, Tektronix, or similar?

[donlisms]

There are many people who can't imagine relying on an analog Tektronix scope; it's not even digital!  It does depend a lot on what you're doing, of course, and there are many people who *do* rely on them.  I prefer my 485 as daily driver, unless or until there is some feature I need on the cheap digital scope.

As to the fear of the unknown... you'd want to try and get as good a sense as possible of how well it's working before you buy, though there is always risk.  I have a couple that were in great shape, and a couple that need work.  The nice thing about it is the manuals are readily available and amazingly helpful.  And while there may be obscure parts that fail, my guess is that you'd mostly need standard things like... capacitors.  Plus there is a helpful community of experience out there. And videos. IOW, my view is once again "don't be scared."  :-)

I also very firmly believe that your projects in your bench will tell you when it's time to get more gear, as opposed to trying to predict the future and what you might need someday.  This is not necessarily a popular view, and doesn't always line up well with the Joy of Acquisition of New Shiny Baubles!

[wizard69]

Hello. I trust your experience more than my research. I’m going to spend in the neighborhood of $200 on a power supply.

That really isn't a lot of money to buy new.   In fact I wouldn't bother with a lab supply.

I need/want dual output, up to 30v, not sure about amps. I don’t mind servicing older stuff and actually like vintage stuff that is reliable but need it to work from the start as my project has a timeline.

Timelines imply a project that is for money in most cases.   As such it might make sense allocating more money for new hardware.   On the flip side a project implies that you might know the exact voltages and currents required.   If so fixed voltage industrial/commercial supplies are very cheap.    You can literally find hundreds of such supplies from the regular distributors and they can be cheap.

Based on past experience would you buy two KORAD KA3005’s (or comparable) or would you purchase a used, dual output HP, Tektronix, BK or similar off of eBay. I’m new with limited knowledge so if you have other suggestions please feel free to share other possibilities. Any help is appreciated.

There are numerous suppliers of lab type variable voltage supplies and they often come up for sale or auction.   You can also go a bit upscale and get supplies used in test and measurement systems, often surprisingly cheap on auction or used.   However the lack of information related to what makes this a pressing need really means we can't offer ideal advice.

[Electro Fan]

Given your questions and comments I don’t think you will regret jumping into the rabbit hole - but to get the best experience I suggest using a good ladder.

The trick to getting a ladder that will enable an ee (non-degreed electrical enthusiast) to safely and enjoyably climb in and out of the rabbit hole, imo, is to get well grounded (haha) in Ohm’s Law.  This means doing enough simple math to understand and reasonably predict the relationships that result from V=IR. 

Print the wheel and post it near your bench.
https://www.formulacalculators.com/ohms-law-calculator/

DC is a good place to start, then when you get to AC you can build on the foundational concepts and math learned with DC.  AC will add things like RMS.  Along the way you will start to recognize the concept of reactance as you distinguish impedance from simple resistance. The oscilloscope can help you visualize some of this and if it has useful math or measurement readouts the scope can help you connect the wave form insights to measurement insights.  Things like Peak to Peak vs average vs RMS and 50 ohms vs 1 M ohms will start to show up over and over like markers on your rabbit hole ladder.  This is a long way of saying you don’t need an expensive DMM but I’d get one with TRMS vs average RMS.  When you see numbers like .707, 1.414, and 2.828 in your dreams you will know you are making progress

And when this chart makes sense you will be another ladder rung proficiently into the rabbit hole.
https://www.minicircuits.com/app/AN40-012.pdf

fwiw, from an early rabbit hole journey:
https://www.eevblog.com/forum/testgear/fluke-17b-rms/

For high voltage stuff, get a Fluke or Brymen.  For low voltage stuff get one or two Aneng 8008 (save money and get good features with surprisingly good accuracy).

The KA3005P adds the programmable PC interface and won’t cost much more than the KA3005D (but you might find the software a tad primitive).  Both the D and P offer excellent value for the price.

As for scopes, just take the elevator into the rabbit hole, get off on the Siglent floor marked HD. 

This advice is intended to save you time and money.  Enjoy the journey, it is likely to be fascinating.

edit:  Maybe add one Aneng 8008 from Amazon to your Fluke and Klein collection and you are set on DMMs.

This is all a bit intimidating... SOOO much information! I downloaded the charts. Thank you. After looking closer at the Fluke 17b I am wondering if that is actually the model I have. If it is I didn't realize it is so capable. When I return I'll have a look. As for the scope, I just don't know if I can manage something new in the budget. Even the 804 @ $439 is steep for my (initial) plans. And, it is out of stock, currently. When watching the Oscilloscope training vids I had myself convinced a used Tektronix would suffice. Is that not a good route to take? I'm a bit weary of buying used for such an important tool but I feel if I wait for the perfect tool at the perfect price I may never get started. Thoughts?
* This advice is intended to save you time and money.  Your consideration is much appreciated! Thank you.

Still not sure what your project and overall objectives are but I’d recommend making it fun and educational.

One easy low cost way to do that if you are just getting started is to stick with DC circuits until you get comfortable with Ohm’s Law.  For this you can postpone an oscilloscope.

Just get the Korad and use your existing DMM(s).  Get a couple breadboards, a package of LEDs, and an assortment of resistors, plus some 22 gauge solid wire, and a wire stripper - all easy to get on Amazon.  Make simple circuits in various combinations until you can predict (calculate) what voltages and resistances will result in what current as shown on the Korad readouts and as confirmed on your DMM(s).

Watch some youtubes and post your breadboard layouts and test results and questions here.  Total investment less than $200 including the power supply.  (Or to really save on the budget just use a 9V battery - but I think the flexibility and functionality of the power supply will speed up the learning process and make it more fun).

When you get Ohm’s Law working as expected you can move on to capacitors or maybe transistors or other components, or maybe try an Arduino if you are interested in digital and software.  Lots of cool and useful stuff can be learned and built without an oscilloscope.  If you go this route and decide you need or want a scope you can revisit the used analog vs new digital vs both discussion.  Enjoy the journey.

[MaxBishop]

Hello. I trust your experience more than my research. I’m going to spend in the neighborhood of $200 on a power supply.

That really isn't a lot of money to buy new.   In fact I wouldn't bother with a lab supply.

I need/want dual output, up to 30v, not sure about amps. I don’t mind servicing older stuff and actually like vintage stuff that is reliable but need it to work from the start as my project has a timeline.

Timelines imply a project that is for money in most cases.   As such it might make sense allocating more money for new hardware.   On the flip side a project implies that you might know the exact voltages and currents required.   If so fixed voltage industrial/commercial supplies are very cheap.    You can literally find hundreds of such supplies from the regular distributors and they can be cheap.

Based on past experience would you buy two KORAD KA3005’s (or comparable) or would you purchase a used, dual output HP, Tektronix, BK or similar off of eBay. I’m new with limited knowledge so if you have other suggestions please feel free to share other possibilities. Any help is appreciated.

There are numerous suppliers of lab type variable voltage supplies and they often come up for sale or auction.   You can also go a bit upscale and get supplies used in test and measurement systems, often surprisingly cheap on auction or used.   However the lack of information related to what makes this a pressing need really means we can't offer ideal advice.

Thank you for the feedback, wizard69. My initial plan was to buy all used gear but it is looking like I may buy the KORAD for future testing but, for this project I'm using an Allen Bradley power supply.
It isn’t something I’ll get paid for. Not the work I’ll put into it, anyway. It is something I want to use at work, though. Specifically, I want to prove there are other options than cost prohibitive industrial surveillance systems. I’ve considered using a PLC but I don’t know anything about the programming languages typically used.
It’s only pressing because I’ve put a tentative completion date on it.

[MaxBishop]

Given your questions and comments I don’t think you will regret jumping into the rabbit hole - but to get the best experience I suggest using a good ladder.

The trick to getting a ladder that will enable an ee (non-degreed electrical enthusiast) to safely and enjoyably climb in and out of the rabbit hole, imo, is to get well grounded (haha) in Ohm’s Law.  This means doing enough simple math to understand and reasonably predict the relationships that result from V=IR. 

Print the wheel and post it near your bench.
https://www.formulacalculators.com/ohms-law-calculator/

DC is a good place to start, then when you get to AC you can build on the foundational concepts and math learned with DC.  AC will add things like RMS.  Along the way you will start to recognize the concept of reactance as you distinguish impedance from simple resistance. The oscilloscope can help you visualize some of this and if it has useful math or measurement readouts the scope can help you connect the wave form insights to measurement insights.  Things like Peak to Peak vs average vs RMS and 50 ohms vs 1 M ohms will start to show up over and over like markers on your rabbit hole ladder.  This is a long way of saying you don’t need an expensive DMM but I’d get one with TRMS vs average RMS.  When you see numbers like .707, 1.414, and 2.828 in your dreams you will know you are making progress

And when this chart makes sense you will be another ladder rung proficiently into the rabbit hole.
https://www.minicircuits.com/app/AN40-012.pdf

fwiw, from an early rabbit hole journey:
https://www.eevblog.com/forum/testgear/fluke-17b-rms/

For high voltage stuff, get a Fluke or Brymen.  For low voltage stuff get one or two Aneng 8008 (save money and get good features with surprisingly good accuracy).

The KA3005P adds the programmable PC interface and won’t cost much more than the KA3005D (but you might find the software a tad primitive).  Both the D and P offer excellent value for the price.

As for scopes, just take the elevator into the rabbit hole, get off on the Siglent floor marked HD. 

This advice is intended to save you time and money.  Enjoy the journey, it is likely to be fascinating.

edit:  Maybe add one Aneng 8008 from Amazon to your Fluke and Klein collection and you are set on DMMs.

This is all a bit intimidating... SOOO much information! I downloaded the charts. Thank you. After looking closer at the Fluke 17b I am wondering if that is actually the model I have. If it is I didn't realize it is so capable. When I return I'll have a look. As for the scope, I just don't know if I can manage something new in the budget. Even the 804 @ $439 is steep for my (initial) plans. And, it is out of stock, currently. When watching the Oscilloscope training vids I had myself convinced a used Tektronix would suffice. Is that not a good route to take? I'm a bit weary of buying used for such an important tool but I feel if I wait for the perfect tool at the perfect price I may never get started. Thoughts?
* This advice is intended to save you time and money.  Your consideration is much appreciated! Thank you.

Still not sure what your project and overall objectives are but I’d recommend making it fun and educational.

One easy low cost way to do that if you are just getting started is to stick with DC circuits until you get comfortable with Ohm’s Law.  For this you can postpone an oscilloscope.

Just get the Korad and use your existing DMM(s).  Get a couple breadboards, a package of LEDs, and an assortment of resistors, plus some 22 gauge solid wire, and a wire stripper - all easy to get on Amazon.  Make simple circuits in various combinations until you can predict (calculate) what voltages and resistances will result in what current as shown on the Korad readouts and as confirmed on your DMM(s).

Watch some youtubes and post your breadboard layouts and test results and questions here.  Total investment less than $200 including the power supply.  (Or to really save on the budget just use a 9V battery - but I think the flexibility and functionality of the power supply will speed up the learning process and make it more fun).

When you get Ohm’s Law working as expected you can move on to capacitors or maybe transistors or other components, or maybe try an Arduino if you are interested in digital and software.  Lots of cool and useful stuff can be learned and built without an oscilloscope.  If you go this route and decide you need or want a scope you can revisit the used analog vs new digital vs both discussion.  Enjoy the journey.

Thank you, Electro Fan. This sounds like a great plan for me. I'm going to utilize many of your suggestions. As far as my project, it's embarrassingly simple. I want to make a production machine surveillance system. The first step will be to count production pieces, input with one sensor and output with the other. Then, with some basic programming I can determine the % waste (raw material). If that all goes well, I’ll add another sensor at a different location in the process.

[Electro Fan]

Maybe just learn/experiment/prototype with an “Arduino sensor kit” from
Amazon.  An alternative to the oscilloscope would be a low cost (~$20) logic analyzer from Amazon or eBay plus free Pulseview software.  The Arduino or Rasberry Pi are excellent platforms for learning the intersection of electronics hardware and software; Arduino is a notch easier if you haven’t done much/any coding.  You can power the Arduino from a computer USB cable as you program it, so even the Korad could move to Phase II.  If you get TEA syndrome you will probably recognize the symptoms.

https://sigrok.org/wiki/PulseView