Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Hello! I am a computer science and AI student, but I am getting into hardware.
Over the last few weeks, I have become rather adept at designing circuits and PCBs (I might have audited a couple of courses but that doesn't matter... right?). I have designed my own version of a maker board -- imagine a perfboard but on steroids and some built-in stuff to make testing new components and practically applying what I learned and that jazz. Needless to say, I am bored with making power supplies and maker boards, and I am looking for new ideas, hence the thread name.
I started out using EasyEDA (and having a friend doing all the SMD soldering for me), but I am now using Altium Designer 20 (and doing MOST of my own SMD soldering). I am ready to tackle pretty much any project, even if I need to hit the books again before I can do anything, so send anything my way.
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Garrett Gonzalez-Rivas || Python? Never heard of her, but I can assemble you something
 

atferrari

Joined Jan 6, 2004
4,090
Do you feel inclined to digital or analog? This last, I always found it rather difficult but rewarding when something is finished and working. Opamps could be your focus for starters.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Do you feel inclined to digital or analog? This last, I always found it rather difficult but rewarding when something is finished and working. Opamps could be your focus for starters.
I have done a little work with op-amps but not an analog to digital. My friend suggested a digital/software PSU with a rotary digital encoder and some stuff, I'll look at ADCs
 

atferrari

Joined Jan 6, 2004
4,090
I have done a little work with op-amps but not an analog to digital. My friend suggested a digital/software PSU with a rotary digital encoder and some stuff, I'll look at ADCs
Make it with dual output. You never needs that but the day you need two different voltages, building something in a hurry is cause of problems. Negative voltage is to be available.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Make it with dual output. You never needs that but the day you need two different voltages, building something in a hurry is cause of problems. Negative voltage is to be available.
Got it. Thank you very much. Is there anything else that would be nice for a PSU? I thought about having a switch that makes an amperage cap, but I'm not sure what else would be useful
 

MrChips

Joined Oct 2, 2009
21,822
Medium power 0-20V, 0-2A
Dual Output, both floating
Voltage limit adjust
Current limit adjust
Voltage readout analog or digital
Current readout analog or digital
(4 readouts in total - not shared readouts)

A separate higher power single supply 0-40V, 0-10A.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Medium power 0-20V, 0-2A
Dual Output, both floating
Voltage limit adjust
Current limit adjust
Voltage readout analog or digital
Current readout analog or digital
(4 readouts in total - not shared readouts)

A separate higher power single supply 0-40V, 0-10A.
Would negative voltages matter?
 

MrChips

Joined Oct 2, 2009
21,822
Would negative voltages matter?
Yes, negative voltages matter.

The way you do this is you create two identical floating supplies.
"Floating" means that the supply is not referenced to any potential. The supply itself can be either a positive or a negative supply depending on how you connect the terminals.

For example, two 9V batteries can be a bipolar supply providing +9V and -9V, or it can be a single +18V supply or a single -18V supply.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Yes, negative voltages matter.

The way you do this is you create two identical floating supplies.
"Floating" means that the supply is not referenced to any potential. The supply itself can be either a positive or a negative supply depending on how you connect the terminals.

For example, two 9V batteries can be a bipolar supply providing +9V and -9V, or it can be a single +18V supply or a single -18V supply.
I meant that because the PSU is not analog, if I should incorporate negative voltage natively or just connect the terminals in the opposite polarity
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
I meant that because the PSU is not analog, if I should incorporate negative voltage natively or just connect the terminals in the opposite polarity
I'm not sure if that makes 100% sense, I mean, should each floating output have the negative voltage that can be controlled by connecting them with a switch or relay or should I have it be controlled in software?
 

MrChips

Joined Oct 2, 2009
21,822
I meant that because the PSU is not analog.
I don't know what you mean by that statement. All PSU are analog as far as I am aware.

Here is a photo of a typical single output bench power supply.

1581291416285.png

You will see three terminals at the output. Don't let this fool you.
The red and black terminals are labelled + and -. This does not mean that there is +ve and -ve voltage at the outputs. This is the way "floating" power supplies are designed and labelled.

The GND connection is not connected to the PSU circuitry. GND connection is for safety.

If you do not understand what is a "floating" PSU just ask for more explanation.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
I don't know what you mean by that statement. All PSU are analog as far as I am aware.

Here is a photo of a typical single output bench power supply.

View attachment 198714

You will see three terminals at the output. Don't let this fool you.
The red and black terminals are labelled + and -. This does not mean that there is +ve and -ve voltage at the outputs. This is the way "floating" power supplies are designed and labelled.

The GND connection is not connected to the PSU circuitry. GND connection is for safety.

If you do not understand what is a "floating" PSU just ask for more explanation.
A PSU does not have to be analog per se. The voltages are not controlled by a 10-turn pot and a switch doesn't open or close the circuit. It's digital and digitally controlled. A digital rotary encoder tells a microcontroller how to affect the input to output procedure, and a switch tells the microcontroller to open and close the circuit. The microcontroller can also switch the output directions and pretty much anything else. I beloved I understand what you mean by floating but please point out anything that doesn't seen to make sense.
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
A PSU does not have to be analog per se. The voltages are not controlled by a 10-turn pot and a switch doesn't open or close the circuit. It's digital and digitally controlled. A digital rotary encoder tells a microcontroller how to affect the input to output procedure, and a switch tells the microcontroller to open and close the circuit. The microcontroller can also switch the output directions and pretty much anything else. I beloved I understand what you mean by floating but please point out anything that doesn't seen to make sense.
Believe**
 

Thread Starter

GarrettGR

Joined Jan 14, 2020
10
Tell me if I am wrong in my belief, I'm still new to this. The ”gnd” is connected to mains ground and is not attached to the PSU’s internal circuitry. The ”-” is where electrons flow from and towards the so-called positive polarity ”+” (note I am using real direction not conventional positive to negative). To achieve a negative voltage you would connect the device in reverse with what was connected to ”-” to ”+” and vice versa. Meanwhile, with dual outputs, as pointed out, it allows you to connect them in either series or parallel to achieve the same effect but with varying voltage and current potentials. However, with a digitally controlled PSU, connecting the leads in reverse would not be necessary because the micro controller could simply assign the two PSU outputs to become the reversed polarity. I believe that should make sense, I can include a simple diagram if that would be helpful.
 
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