Electronics Fashions

Black gives the controls better crontrast. Ever try using that new HP Prime calculator?

Cheers

Wow that is old! I was born that year ;-)

Took into the early fifties before I had radio working.

transmitted anything..

I dunno, never payed much attention to the 'outside' Was playing with my Voltcraft clamp-on current / volt meter yesterday. After a 'smart' meter was installed here a week or so ago, mains voltage has dropped a bit.. Originally the neutral and ground were connected here at the house, The technician that was replacing the meter said: "That is no longer allowed", so disconnected it an put an earth-current sensor switch into it too. So now, if you connect earth and neutral the meter switches the power off... no more power.

OK, but then my UPS started making noises all week even when power, trying to recharge its battery. Bit of scoping (Trio old analog scope, grey color) found a surprising low mains voltage, measured mains, way below 230V it should be here and varying, Tried a few things: old 230V to 12 V transformer, put the 12V in series with the mains to get he voltage around 230V or a bit above that, tested if the UPS liked that better. And then, after that UPS switched off (low battery), late last night put everything on my 250 Ah lipo battery with 12 V to 230 V pure sinewave converter driving the UPS to charge its battery Basically you no longer need the UPS that way,, Has run all night from that lipo battery with several Raspberries and other electronics as load. amazing, it now shows 91 percent battery left... I need my own nuclear power source... ;-)

As to that Voltcraft clamp-on meter, that was amazing me how good it worked getting all sorts of AC and DC currents, has an auto-scale very accurate voltmeter too and as to the subject: it is GREY with a black front:

Also the Voltcraft soldering iron I use works perfectly after 25 years

I haven't been able to find a good air-drying crackle-finish paint for years. Very good gloss results could be achieved by painting the panel in matte black, then putting on white transfer lettering, then several layers of clear protective varnish.

Currently my panels are drawn by computer, then a mirror-image version is printed on overhead-projector acetate sheet with a laser printer. The print side is sprayed over with white paint, which fills in all the 'white' (i.e. non-printed) lettering. Finally it is stuck to the equipment with double-sided adhesive tape. This leaves the outside surface unprinted and finger-proof.

Panels made this way have proved adequately durable for moderate use and they are easy to change if the equipment has to be altered.

There is an art to panel layout, not just grouping associated controls together, but drawing a box around them, can make a huge difference to useability.

On Tue, 29 Sep 2026 08:42:32 GMT, Jan Panteltje snipped-for-privacy@comet.invalid wrote: <snip>

I think you'll find that your Voltcraft clamp-on is made in China. . . . . the manual is in chinese . . . . .

I have it's spitting image, in bright red, from Uni-T.

RL

I've seen four engineers sitting around for half a day, debating where the 1/0 switch and other indicators should be, when reviewing a working sample 'out of the box' SE Asian device, for re-branding.

Engineering ain't what it use'ta bin.

RL

The "art" is not just limited to layout. Size of controls, *type* of control (push on/push off vs toggle?), potential (related) uses, etc. Color, contrast, etc.

Physical controls can't be repurposed as easily as "virtual" ones so the decision you make has to continue to make sense, over time.

"General purpose" Automobile controls seem to be universally poorly conceived -- in terms of placement, modality, functionality, etc. Why can I use THIS menu when the vehicle is in motion but not THAT menu?

And, adding voice just makes them worse (because the recognizers can't hit the ~100ms window users expect for feedback)

Cars and thermostats and microwave ovens should have knobs that you can grab and turn without a lot of fumbling and thought and taking your eyes off the road or whatever.

It's illegal here to use your phone while driving, but it's OK to navigate a giant touch-pad screen.

Menus and screens should never be used for things that have to be controlled in real time - they should be completely illegal in cars.

All that matters is that the user have some assurance (that doesn't have to be visually confirmed!) that his actions/intentions have been seen by the device. And, the assumption that, having been seen, they will be acted upon -- eventually.

A physical button that one pushes would be equally bad as a control -- /if the button press wasn't GUARANTEED to have been seen when *felt*/!

If I have to look at a screen to verify that something I've *spoken* has been recognized -- and recognized correctly -- then there is no value to speech as an "eyes-free" input modality.

If I have to look at a screen to verify that the three "clicks" I felt as I rotated the temperature setting have been seen as a "three degree offset", then having a dedicated knob offers little value over a virtual "slider" drawn on the screen.

Our washing machine has an "infinite knob" as a "mode selector". The knob is cogged so you have some haptic feedback. And, the cogging happens at essentially the same points as the selection offsets, marked on the dial.

So, you "feel" your travel to the next detent and THINK you have selected the next mode...

But, you haven't. You have to keep rotating the knob until it chimes to indicate "you are now at the next mode". And, count the number of such chimes to figure out how many modes you've passed through. Regardless of the number of "steps" you've felt it make.

Then, what's the point of the haptics? Why not let the knob spin freely, with a small bit of drag -- as your EARS (and eyes) are required to understand what your HAND is doing!

The worst aspect of many designs is a knob which moves the controlled function backwards if it is rotated too fast. Surely it can't be hard tp sample a bit faster and avoid aliasing? John

If you can't look at the control and it is part of a menu, how do you know the action you have taken is the one you thought you were taking? It should be one contol per one function. A row of identical switcvhes, however well labelled, is equally bad - you need to be able to tell by feel or unmistakable position the function you are controlling.

If you have the luxury of no time pressure, you can happily waste anything from seconds to hours scrolling through menus but when things have to be controlled rapidly in real time, individual controls are the only sensible answer. Knobs and switches also have two other useful properties: they tell what setting they are on by feel and they remember that setting until you change it, even if the power fails.

(A friend has had several microwave ovens in succession, each one of increasing complexity and decreasing ease of use. One day at my house she watched me using the mechanical timer on my 30+ year-old microwave oven and has decided to scrap her latest all-singing-all dancing white elephant and buy a model with a motor-driven timer if she can find one.)

For low volume finish, years ago, could buy black crackle paint. Brushed on, but needed paraffin heater fumes to cure it. Can but it in aerosol now, air drying, but black does show the muck, as do black cars. Paint all my home brew panels red these days, or grey, depending on mood.

China will build to any quality you like, for a price. A lot of junk these days, but some of it is very good.

Auto radios used to have pushbuttons and control knobs only, which you can use to tune and set volume. Modern stuff is rubbish in that respect, but I guess an lcd is cheaper and can include loads of "features", that you never needed or use, and need a phd to navigate.

Rigol scopes are excellent.

We have a very nice Uni-T thermal imager.

Often Chinese test equipment hardware is good but the user interfaces are bizarre.

I see such interfaces as examples of the engineer designing the interface and not a domain specialist.

"See? Look! You can pick from any number of choices just by spinning this knob..."

"Yes, but, you have to SEE those choices to know when you've got the correct selection! (because you have no other feedback to indicate that the machine is aware of how far YOU think the knob has moved)"

Also, having a *single* UI that has to address multiple concurrent processes is just brain damage.

Stove/oven had the "big knob" sort of UI.

"OK. Select the oven to use. Scroll through the cooking modes available. Ah, 'convection roast'! ENTER. Now, select a temperature... ENTER. Now, a duration... ENTER. And, what should we do when the timer expires?... ENTER. OK, I guess we can START the oven..."

But, halfway through this silly process, the timer for the OTHER oven expires and the display switches to inform you of that fact -- and, ask if you want to continue cooking for another 5 minutes...

"No, I want to finish setting up the OTHER oven! How do I get back to THAT 'process'?"

Or, set a timer for an hour. Display is configured to blank after a few minutes -- leaving shiny black glass with no sign of any controls OR INDICATORS. Come into the room

And, how do I *find* a control when the display is blank? Is the button to turn on the oven light HERE? Or, here? Or, maybe HERE?? Damn, no, I turned on the warmer by mistake...

Its devices like this that make you really want to hack the implementation and send new firmware (no sources!) back to the manufacturer: "See? This is how it SHOULD have been done..."

For often used devices, you likely already *know* where the control you're interested in is located.

SWMBOs vehicle has a touchscreen for most interactions. To select audio source (HiFi), a set of ~12 tiles are presented. Eight are displayed at a time: "Next Screen" for the balance.

When she is driving, I arranged the tiles so the sources that she most often uses appear at the start of the layout. (Disk, FM being the two most popular). So, all she has to do is touch the top left or bottom left to choose between those choices.

When I am driving, the two most common choices are BT and USB so those tiles inhabit those precious locations.

The choices neither of us select are delegated to the "second page" of our respective layouts.

We can also select input sources using buttons on the steering wheel. But, that requires you to watch a different display as neither of us have memorized the FACTORY DESIGNED order that the selections appear, there. (really? I can arrange the order in one place but not another -- for the same functionality??)

But a menu need not be a static design. As in the case of the input sources, you can design the menu to present choices in a manner that facilitates certain selections.

My current project expects users to be disabled, to varying degrees. If you can't *see*, how do I present a set of controls that varies with the application being controlled? Surely, a giant panel of switches -- one per function -- would be MORE intimidating than a panel that adapts to the task at hand.

The problem there is linking the user's notion of the control layout with the machine's.

But, there's no reason that has to be visual!

Many decades ago, we bought a microwave oven for my MinL. I had my preferences -- based on my experiences with them. Wife opted for the big (nonlinear!) dial: "My Mom can understand this..."

OTOH, I much prefer pushing *a* button to reheat my beverage. Another to defrost the frozen Marinara sauce. Another to heat a frozen dinner.

When I was canvasing disabled users (for current project), one of the common design constraints offered (unsolicited) was "make it WIPE-CLEAN".

This left me dumbfounded as it was so non-technical.

But, the point was that anything that they would be handling would quickly dirty from oils and dirt on their hands. And, they wouldn't see all that crud hiding in knurl-textured surfaces.

BUT FOLKS STANDING NEARBY *WOULD* -- and would be "grossed out" by how unsanitary the item looked! Solution: smooth finish that could easily and thoroughly cleaned WITHOUT visual feedback as to its current state of cleanliness.

The point in all of these is that the UI/UX has to address the targeted demographic and the targeted application domain. A "big knob" likely does neither (but, is easy for an engineer to imagine)

Another bad example:

Set general purpose timer (selected from a menu that is called up by another button (touch surface).

dial X hours ENTER dial XX minutes ENTER START

(seconds are always reset to 0 any time you specify/*edit* a time! I guess these folks like cooking big roasts instead of baking cookies!)

First: why two steps to specify a time? how many people set timers for more than 59 minutes? Why can't it count up from

Second: why can't the timer offer me the most recent setting as "repeat last interval"? Why force me to keep setting it every 5 minutes (for another 5 minutes) ESPECIALLY IF I JUST SET IT A FEW MINUTES AGO???

"I'm baking cookies -- 5 minutes on each rack, then move to another rack. Now, I want to set the timer for 6 and a half hours to BAKE a turkey..."

C'mon, you've already got a hint as to what I am LIKELY doing. (Bake, Broil, dehydrate, proof, convection bake, convection broil, etc.) Doesn't that suggest the sorts of cooking times I might be interested in????

Engineers/programmers make lousy UI designers.