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I always enjoy projects like this. Both because the are artistically neat and because the give me all sorts of ideas.
It's certainly nice to see the nice woodworking in combination with a simple elegant design. Ways to keep more than one brain center active!
I thought it was pretty cool, but a bit expensive for what it was.
So I made my own with a PIC chip: https://www.n1kdo.com/meter-clock/index.html
Mine is more of a novelty than a accurate clock. It is a interesting desktop geegaw to invite discussion.
I expected seconds arrow to move much more smoothly than in the video is 10Hz control just too slow?
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I think I don't completely understand your idea. The current flowing through the amperemeter¹ depends on the voltage and the resistance of the incandescent(?) lamp. To vary current by the minute, you would need a digital resistor or potentiometer, I guess. Is that your suggestion? ¹) I just found out that it is more commonly called 'ammeter' in English - which is so unintuitive that I prefere 'amperemeter'.
If you have a feedback loop I'm sure you can still do it with an either implicitly or explicitly filtered PWM. Remember we're talking averages not instantaneous, so the average current through the bulb should be proportional to the average voltage across it, though the resistance will change as the bulb heats hence the feedback. You could also do this with a buck/boost regulator and current sense resistor plus op amp…
V=I*R
If V = Hours and I = Minutes, then by necessity R=Hours/Minutes. Typically a light bulb has mostly fixed resistance (R). Adding a potentiometer to the circuit allows you control the value of R.
This is beautiful, and I like it a lot, but I was slightly disappointed to find that they do not function by increasing the voltage as the day goes on. But then I remembered that that's how pins work. It IS measuring voltage!
Transistors are much more efficient full on or full off. So for the most part for transistor based voltage control they pulse the transistors with a duty cycle equivalent to the voltage needed and integrate it with capacitors, keep the pulse on 25% of the time you have 25% of the voltage sort of thing. Thus the acronym PWM (Pulse Width Modulation) Note that transistors can be controlled to directly regulate the volta…
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If you have a feedback loop I'm sure you can still do it with an either implicitly or explicitly filtered PWM. Remember we're talking averages not instantaneous, so the average current through the bulb should be proportional to the average voltage across it, though the resistance will change as the bulb heats hence the feedback. You could also do this with a buck/boost regulator and current sense resistor plus op amp…
"average current through the bulb should be proportional to the average voltage across it" That is exactly correct, the reason they were seeking clarification, and the core of suggested solution. V=I*R If V = Hours and I = Minutes, then by necessity R=Hours/Minutes. Typically a light bulb has mostly fixed resistance (R). Adding a potentiometer to the circuit allows you control the value of R.
That being said, the bulb does have a well-defined resistance at a given point in time, so voltage and current are of course not quantities that can be indefinitely controlled.
This falls into the same category as “why isn’t my power supply with voltage and current controls working correctly?!?”
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In my experience, having a project/goal will make it do-able for you. You have both the motivation and an target (dare I say, North Star?) in sight.
You’re exactly right..that’s how I end up learning tech stuff. It’s not working very well with modelling though. I’ve set my sights too high, the projects are too involved
I saw somebody's arduino based voltmeter clock way back around 2014, I think here: https://maniacallabs.com/2014/07/08/meter-clock-pt1/ I thought it was pretty cool, but a bit expensive for what it was. So I made my own with a PIC chip: https://www.n1kdo.com/meter-clock/index.html Mine is more of a novelty than a accurate clock. It is a interesting desktop geegaw to invite discussion.
Can't access it. Connection attempts time out.