I have another idea !
Forget "very nice" and "practical". Me and you it seems can't find any good idea for it.
Let's make a very -stupid- and -pointless- device with this coil meter. Like a joke.
The most inventive one, wins.

 

Hello,

Here I have a collection of link sites related to electronics:
http://www.101science.com/eleclinks.htm
https://circuitsarchive.org/
https://www.epanorama.net/
http://www.solorb.com/elect/
http://www.talkingelectronics.com/te_interactive_index.html
https://www.gadgetronicx.com/
https://www.radiolocman.com/

Bertus

 

yes I get it, but my mains current does not fluctuate like @wayneh said it is in his side.
What else I can use it for?

You mean that your premises takes the same amount of power all day?
Really?

 

You mean that your premises takes the same amount of power all day?

Aaah you refer that for the entire apartment ? Wow, I didnt think of that. Hah.
I was thinking on my working bench.

 

I recently -repaired a VERY damaged- coil meter that I scrapped from somewhere sometime in my life. I had this stacked in a box forever.
Now is working very nicely. Originally was sensitive between 2-10mA but after I repair it, is about ~30mA sensible. I had to recalibrate the shoyk out of it to make it functional and without needle bumping or dragging or touching. The tiny spiral springy watch coil(s), 2 on each side, they were the calibration element. It took me 1 day literally to concentrate only on it to put it on its feet. I also had to reconstruct (from melted plastic) a very important structural element that shattered in many pieces. Its made from a very nasty fragile aluminium alloy that crumble. This structural element was holding 1 springy coil and a very tiny axel. ETC-ETC-ETC... you get the idea. It was VERY bad.
Im very happy it is working very good now.
- All I need is a VERY NICE project idea to integrate this into. Well, actually many ideas if possible, a little brainstorm and then I want to pick the most cool idea.

Thank you !

That is begging to be a VU meter for a steampunk style tube amplifier.

 

That is begging to be a VU meter for a steampunk style tube amplifier.

nice idea, unfortunately I am not into audio amplifiers at all, and I can not find a purpose for one. I have all I need already buy and working for probably 10-15 years now. If there are other tube amplifier devices that you may refer to, then Im too young for tubes and no experience with them. All I know is they run on high voltage like 100V to 1kV some of them ... some DC some AC, I think. I watched a lot of Mr Carlson on youtube and I am quite familiar with them, but not experienced because I never put my hands on one and probably never will, since they are very expensive. I do have a preferation from all of them, this magic eye tube:

some day, when I will be able to make money, I will buy one. Until then... eheheee.
Nice idea though.

 

Aaah you refer that for the entire apartment ? Wow, I didnt think of that. Hah.
I was thinking on my working bench.

Yes. You could put a split-core current transformer (quite safely) around the incoming supply cable.

 

Yes. You could put a split-core current transformer (quite safely) around the incoming supply cable.

Yes, I see your point now - very smart idea actually !

 

I think I found an interesting idea: A presence sensor !
When my hand is near some receiving coil or some sensor, the needle will move.
Also some beeping as fast as the needle goes higher in value.
Cool eh?
What presence sensor do you recommend? in the range of 10cm to 20cm (adjustable) will be best.
Beside my 2N7002 super sensitive mosfet with a coil and a matchstick/diode/10Mega on its Gate. (see? I remember stuff)

 

I use one of those fed by a ~1cm2 solar cell to show percentage of insolation to compare with solar power being generated and for aiming solar panels. Adjusted to full scale as the maximum ever read in a super clear day with perpendicular sun rays.

 

I think I found an interesting idea: A presence sensor !
When my hand is near some receiving coil or some sensor, the needle will move.
Also some beeping as fast as the needle goes higher in value.
Cool eh?
What presence sensor do you recommend? in the range of 10cm to 20cm (adjustable) will be best.
Beside my 2N7002 super sensitive mosfet with a coil and a matchstick/diode/10Mega on its Gate. (see? I remember stuff)

There are lots of Thermin circuits on the internet. You could easily add a simple amplitude detector to drive your meter.

 

I use one of those fed by a ~1cm2 solar cell to show percentage of insolation to compare with solar power being generated and for aiming solar panels. Adjusted to full scale as the maximum ever read in a super clear day with perpendicular sun rays.

interesting idea but im afraid is too advanced for my nose, and I didnt fully understand your project, only fragments of it ... since I do not have a solar cell power module, like those big modular panels used on roofs for house powering that I get the impression you are referring to.
- I do have some brand new power cells but very small, for testing and playing with.
And I had to find the data with this occasion, for my solar panels I have in stock, not many, 10pcs and 2pcs.

and this other one model:

- And here is another nice project I was actually reflecting upon but afraid of starting it, for many many years.
A Solar Charging Accumulator ! For the small ones 1.2V Ni-Mh:

 

There are lots of Thermin circuits on the internet. You could easily add a simple amplitude detector to drive your meter.

yah... it's a GREAT project this one !!!! And is in plan for many years, from 2019 when I build my (first) wall sensing switch with 2N7002 mosfet.
I find it too hard to make, or is that I didnt understood fully its circuit. But it remained in the back of my mind.
Can you show me the most simplistic or quick and dirty one ?

 

if you like pranks, use it with distance sensor but ... label display as something that may catch attention... perhaps "radiation level". optionally produce ticking sound corresponding to displayed value.

 

perhaps "radiation level". optionally produce ticking sound corresponding to displayed value.

we will need a random noise generator similar to a geiger counter sound :
https://www.soundsnap.com/geiger_counter_1
https://www.soundsnap.com/11903601
I find this cct is looking interesting: https://makingcircuits.com/blog/adjustable-noise-generator-circuit/
And, I made it in my sim and is doing something, it is making a "uuuuiiiiii" changing output duty cycle from short to long and reseting to short then long and so on. Hmmm. I want clicks ! I have to make it in reality to hear exactly what is doing. But the good news it is working and also variable !

... and I build it in reality on breadboard. It worked from the first try. But the sound is like a bird chirping when fast and when slow is just slow chirping.
The sound is too high. I used a 5V buzzer, probably that's why the sound is too high.
I need a click sound.
And I make the click sound, only using a very basic 555 circuit - half of that bigger one.

The only problem now it is not random. Hmm.

 

I wish I can make the needle travel way more than it is right now.
Here is what I could make from last night:

 

seem to reach 50% of the scale. what prevents it from traveling further? need more current or getting stuck on some mechanical obstacle?

 

seem to reach 50% of the scale. what prevents it from traveling further? need more current or getting stuck on some mechanical obstacle?

no - just watch the movie and you will get it.

 

This is the cct I manage to make alone. Is kind of working but not really moving the needle too far.
Very interestingly, the sim is actually showing some random LED1 lit up, exactly as in reality.
The sim osciloscope is showing the correct (and also as I imagined) outputs for both the not gate and 555.
In reality Im influencing the Gate so it clicks more often. But it works in the sim - thats the point.
I have no idea what that coil value is, I put that 1uH value from my ass.
Also that buzzer I put a cap here in this sim cct. It doesnt disturb the cct. Probably thats why my LED is litting up randomly.
Any corrections to this cct is welcome. I need that needle to travel waaaaay more than it is doing now - you've seen in the presentation movie how much is moving.
Thank you.

 

A slight improvement from my previeous cct, with a very small increase in the needle trembling but not as much as I want.
Now in this setup, is a tiny bit more responsive than before - imperceptible almost but it is.
My original intention was to use this opamp as a amplifier but it turned out as a (negative) buffer in the end. Still, interesting.