Front Panel PSU Design - Page 1
Forum section: electronics / projects

author: namster
author_rank: Regular Contributor
timestamp: July 21, 2020, 09:08:54 pm
content: Hi I'm resuming a project that I abandoned for a while , I would like to treat in this topic the front Panel of the Single output PSU , with 3 Digit for Current and Voltage , also for control of voltage i used coarse and fine Potontimeter and one Pot for current , to do this I useda PIC with a uln2003 and two 74hc574 to Latch the segment state the principe is relatively simple , for ADC i used a MCP3202 Wich is a two channels 12bits ADC , so i shared this to know what are the points to improve

author: OM222O
author_rank: Frequent Contributor
timestamp: July 21, 2020, 09:24:13 pm
content: Driving all those leds with discrete chips ans 7 segments is outdated. Get an I2C LCD which allows for future firmware updates with additional info like power etc. 16x2 should be fine for what you're doing but I personally orefer the 16x4 or 20x4 ones.Also actual pots tend to be ver unreliable and noisy. I'd usually use a digital pot controlled via a rotary encoder either directly or via the MCU depending on the pot interface (some are step and direction, some are i2c) you can get dual 10 bit ones for very cheap. Pushing the encoder in can switch between fine and coarse or you can use two seperate encoders if you wish.

author: james_s
author_rank: Super Contributor
timestamp: July 21, 2020, 09:29:31 pm
content: Yuck, no thanks. I hate that trend of cheap TFTs on things like power supplies, they are everywhere now and it's because they're cheap. 7 segment LED displays and individual LEDs are much nicer for this sort of thing. LCD character displays like the 1980s style 16x2 are even worse, tiny little characters that you have to be up close to read. Even a small 7 segment LED can be read from across the room at viewing angles approaching 90 degrees.

author: namster
author_rank: Regular Contributor
timestamp: July 21, 2020, 10:09:22 pm
content: Quote from: OM222O on July 21, 2020, 09:24:13 pmQuote from: james_s on July 21, 2020, 09:29:31 pmi chosed a simple 7 Segment and linear Pot for a cost and simplicity reason it has the advantage of being simple, I plan to realize multiple versions of front panel a Analog one and a digital one with DAC

author: Renate
author_rank: Super Contributor
timestamp: July 21, 2020, 10:33:14 pm
content: Yuck! Go with a nice 1.54" OLED!LCDs are dead, dead, dead.If you must do 2 x 16, OLEDs come in character style too.

author: rdl
author_rank: Super Contributor
timestamp: July 22, 2020, 01:27:47 am
content: If all you need to display is a few numbers then LEDs (7 segment) are the way to go. If power consumption is a factor then maybe 7 segment LCD. Readability of small dot matrix LCDs is not great from any distance. OLEDS still have burn-in and fading issues.

author: b_force
author_rank: Super Contributor
timestamp: July 22, 2020, 01:48:24 am
content: I personally don't get the fanboys from either side.Just think about what product you want to make, how it needs to look and feel and what price it needs to be.Plus the amount of time and effort you have to put into it to develop everything, and the technical specs (like power consumption etc).

author: coromonadalix
author_rank: Super Contributor
timestamp: July 22, 2020, 03:51:39 am
content: Quote from: b_force on July 22, 2020, 01:48:24 amExactly +1