Simple Lab Power Supply User Interface Help - Page 1
Forum section: electronics / projects

author: udok
author_rank: Regular Contributor
timestamp: January 04, 2019, 09:30:41 pm
content: I would like to build a triple lab power supply,and need some help with the user interface.It should be a compact design with a decent 3.5 inch TFT,about 11 cm wide and 17 cm high.The electronic is not special, basically a linear regulator witha precision reference and 16 bit DACs.It should have a USB interface for logging anda low current range for measuring standby currents inthe microamp range.I build a first 3D cad model, and attached a picture.Some not so often used features could be reached withthe MENU button.Do you like the user interface?Any ideas for improvements?

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2019, 06:03:22 am
content: Do you want people to design it for you ?? you're going on a hard route here ??You have already built 2 or 3 chanels psu's, simply stack them and connect them, usb, lan, rs232

author: BravoV
author_rank: Super Contributor
timestamp: January 05, 2019, 07:14:02 am
content: Take your time browse thru almost 500 posts of various bench PSUs ->Forum members bench PSUs

author: xyrtek
author_rank: Regular Contributor
timestamp: January 05, 2019, 08:29:43 am
content: No idea how to answer your question, its only a pic without much details. I can tell you how I would like it to be.Bench space is a premium, equipment designed to be stackable is preferred.Buttons size and ergonomics is important.Make it intuitive to use.Whatever you do have dedicated buttons for V and I, one encoder for the both is frustrating at best.Be mindful of encoder steps and button size, some combinations are just plain awful.Implement acceleration on controls that requires it.If you have to click more than twice to get to a menu you have failed.Implement a control panel lock, this is a must.Be sensible with colors and fonts, actually be very sensible.Something that none takes into consideration, we all don't have the same vision and as we get old we all wear glasess...be mindful and avoid filling that tiny display with a gazillion of tiny useless info.Don't try to have all the features that the cool kids rave about, get the fundamentals right.The very obvious but easy to forget, display target and actual output visible at all times.At the very least know I didn't cover 1% of what it takes to make a successful product.Hope this help.

author: JuanGg
author_rank: Regular Contributor
timestamp: January 05, 2019, 08:43:16 am
content: If you are the one using it, no one better than you is going to know what you like. I'd personally have a separate button for each chanel and V and I encoders, that may have secondary functions when other buttons are presed. Anyways, look at examples of PSU UIs and do as you wish.Juan

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 05, 2019, 09:53:23 am
content: What is the idea for the UI behind the picture?How would I set Imax on the 7V channel?What functions would be controlled through the UI?Right off the bat I see 3 channels, 3 display sections and 3 knobs.While each knob has a channel next to it they also have very different things written next to it.What is the idea here?And another thing I notice is that this division into 3 does not go for the buttons.There are 4 of them, why?

author: xavier60
author_rank: Super Contributor
timestamp: January 05, 2019, 10:53:35 am
content: I find it convenient to use the encoder's center switch to toggle between V and I setting.The selected setting flashes but temporarily stops flashing while the value is being changed.When the encoder is rotated more than a certain speed, the setting change accelerates.The small green thing is actually the button for toggling the output on and off.After one minute of no activity, the flashing stops and settings can't be altered until the center switch is pressed.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2019, 01:59:03 pm
content: here's a project :http://www.ianjohnston.com/index.php/projects/57-project-021-home-built-bench-power-supply

author: Dave
author_rank: Super Contributor
timestamp: January 05, 2019, 07:09:50 pm
content: Quote from: coromonadalix on January 05, 2019, 01:59:03 pmPersonally, I would avoid that design like the plague.Things like RC filters in the feedback lines are a dead giveaway that the designer had no clue what he was doing.

author: mvs
author_rank: Frequent Contributor
timestamp: January 05, 2019, 09:42:08 pm
content: Quote from: udok on January 04, 2019, 09:30:41 pmI have mixed feelings about it. I like your ambition to create such small 3 channel lab power supply, but minimalistic UIs are not convinient in every day use.QuoteSeparate output on/off buttons with state indication for each channel are quite handy.

author: udok
author_rank: Regular Contributor
timestamp: January 07, 2019, 12:07:39 am
content: Thanks for the many good remarks.I did not explain much in my first post, but hoped that the pic was more or less self-explaining.I improved the user interface somewhat, as can be seen in the new picture.Space is very limited, therefore i can not add many more buttons.I hope that the basic UI is intuitive enough to control atriple lab power supply without reading a manual.Most of the time i do not need more than +-15Volt @ 0.5A and 5V @ 2A,and i do not have much space on the desk.The accurate current display for each channel could replaceup to three external Multimeters, to save even more space.Each channel voltage is controlled with one encoder.If the encoder is pressed, the current limit can be changed (Xavier60).Button ON/OFF enables or disables all outputs.Maybe pressing encoder x together with the ON/OFF buttoncould be used to enable/disable only channel x?LOCK helps against unwanted changes.Did not know, that this is needed before thinking about it.TRACE chains channel +25V and -25V together.The free encoder could be used to control current directly.MENU opens a menu for not so often used things:- help menu- time constant for display averaging- what to do in case of short-circuit- some display configurations- other thingsGreetings,Udo