Introducing the MagnetoDrive with SmartDial

[smflorkey]

This is looking like something in the 'must buy' category. Will, I think you're going to put a serious dent in my wallet.

 

[Nitroz]

Wow! How did I miss this post! This is amazing and very cool control scheme.

The host that you made is very nice and I think you should make a light just like that with a flared tailcap and, of course your own bezel that mimics the head somewhat. Beautiful creation!

MagnetoDrive chiseled into the light would be an excellent name with some graphics like this ||||||||, except that the bars get thicker as they go to the right.

 

[wquiles]

LOL, I've now deleted the duplicate posts. Sorry for the delay there, Will - I've been away for ~2 weeks.

Thanks man - I will be more patient next time

This is looking like something in the 'must buy' category. Will, I think you're going to put a serious dent in my wallet.

Thank you. I am still travelling a lot for my day job, but I am still making progress towards the next prototype

Wow! How did I miss this post! This is amazing and very cool control scheme.

The host that you made is very nice and I think you should make a light just like that with a flared tailcap and, of course your own bezel that mimics the head somewhat. Beautiful creation!

MagnetoDrive chiseled into the light would be an excellent name with some graphics like this ||||||||, except that the bars get thicker as they go to the right.

Thank you. The next prototype host will be closer to the actual size - I will not be using any Mag parts, so it will have a different look/feel.


Will

 

[Steve K]

a neat and fun design!

As a EE, I have to wonder what sensing technology is being used. I thought I saw the word "hall" in there once or twice, but I would have thought that the current drain would be too high for a device that may sit unused for a long time. Of course.... the little Mag 100 that I have uses an accelerometer, and I haven't noticed it killing the batteries (but it only operates when the tail switch is depressed...)

Looks like a fun project, and I'd love to learn more about the sensing technology if you can share the details.

FWIW, I've been impressed with some of the fancier hall devices out there, especially ones that sense magnetic field direction. The Melexis 90316 is one of these, and similar devices are available from AustriaMicroSystems and Renesaas.

regards,
Steve K.

 

[wquiles]

Steve,

I am using Hall Effect Sensors, but they are not enabled all of the time, so that helps keep current consumption to a min while in the OFF position where I also put the micro-controller to sleep.

I am not done, but so far it has been a fun project indeed. It is good to have a fellow EE here in the forums

Will

 

[BVH]

OK, OK, you EE's are making me feel stupid! Enough!

 

[wquiles]

Quick update on the second host. I am not sure what lens I will use yet, but I got a few to evaluate. To help me evaluate these various lenses I am building a small setup that will allow me to find out what focuses best with each lens, given the LED that I will be using, a Cree XM-L:

Here I am cutting the moving "heatsink" or "pill" that will keep the LED entered:

The post to solder/glue the LED:

Here I am machining the outer "body" which will hold the lens in place - starting with Al tubing instead of a solid bar:

A sliding fit:

Trim:

The two pieces - note in the heatsink/pill the upper one inch has the friction marks (the lower section is 0.002" smaller, so it does not make contact):

I need to drill two holes for the LED wires, and of course solder/glue the LED - hopefully this coming weekend:

I also have to create a lip in the inside of the tube and make some lens holders to that I can test them, but making progress

Will

 

[Th232]

Interesting to see how you've done the LED post. Out of curiosity, since the pad on the LED is rectangular, did you choose to make the post round just because it was easier to do on the lathe, or were there other considerations?

 

[Steve K]

Steve,

I am using Hall Effect Sensors, but they are not enabled all of the time, so that helps keep current consumption to a min while in the OFF position where I also put the micro-controller to sleep.

I am not done, but so far it has been a fun project indeed. It is good to have a fellow EE here in the forums

Will

I didn't notice if there was a separate power switch or not... I assumed that moving the ring would wake the micro up, which would require the halls to be enabled all of the time. .... or... just have the micro briefly power the halls every half second or so, looking for a change of state. I've worked with hall switches such as the Allegro A1101. Its datasheet says it draws 4mA typical, which would kill a battery relatively quickly.

It's always fun to contemplate other ways to implement a function... Instead of using an active device like a hall, an option would be to use a coil to pick up changing flux from a magnet ring. It wouldn't draw any power, and could be used to wake up the micro. The output voltage will depend on the speed of the changing flux, so it might ignore slow changes. This might be a bug, or it might be a feature. The downside is that winding coils is an extra production process that costs money and can go wrong.

best wishes for the project,
Steve K.

 

[wquiles]

Interesting to see how you've done the LED post. Out of curiosity, since the pad on the LED is rectangular, did you choose to make the post round just because it was easier to do on the lathe, or were there other considerations?

Yes, absolutely, just easier on the lathe. This fixture is just for comparing lenses (not to be used in the actual prototype), so this was quick/easy to do in the lathe

 

[wquiles]

I didn't notice if there was a separate power switch or not... I assumed that moving the ring would wake the micro up, which would require the halls to be enabled all of the time. .... or... just have the micro briefly power the halls every half second or so, looking for a change of state. I've worked with hall switches such as the Allegro A1101. Its datasheet says it draws 4mA typical, which would kill a battery relatively quickly.

It's always fun to contemplate other ways to implement a function... Instead of using an active device like a hall, an option would be to use a coil to pick up changing flux from a magnet ring. It wouldn't draw any power, and could be used to wake up the micro. The output voltage will depend on the speed of the changing flux, so it might ignore slow changes. This might be a bug, or it might be a feature. The downside is that winding coils is an extra production process that costs money and can go wrong.

best wishes for the project,
Steve K.

There is no separate power switch. Although I don't have the data sheet in front of me, I seem to recall that my Hall Effect sensor draws something like 0.3-0.4 mA when operational - pretty low power consumption, while giving me a very fast response.

Will

 

[Th232]

That sounds like a really good current draw, if you don't mind me asking, what's the part number? I've found unipolar or bipolar sensors with current draws around that level, but no linear ones that were acceptable for my purposes.

 

[wquiles]

That sounds like a really good current draw, if you don't mind me asking, what's the part number? I've found unipolar or bipolar sensors with current draws around that level, but no linear ones that were acceptable for my purposes.

Ahh, that makes sense. I am using a low power, unipolar sensor.

I found the data sheet: typical power consumption is 280uA (0.28 mA). Send me an email (in my signature) so that I can send you more info

Will

 

[cdrake261]

Can you post a video of the flashlight switch in operation?

 

[Nitroz]

Can you post a video of the flashlight switch in operation?

Here are some videos I took tonight:
MagnetoDrive - moving of the control dial slowly

MagnetoDrive - moving of the control dial at normal speed

MagnetoDrive - moving the control dial very fast – a "flick" to achieve max brightness - "turbo" mode!

This was in his first post.:thumbsup:

 

[wquiles]

Can you post a video of the flashlight switch in operation?

The first post has 3 videos where you see me moving the switch in operation on this mule/prototype - that is why I had that small piece of blue tape in the videos so that you guys could see the movement.

Once I have the second prototype (closer to final design), I will make new videos.

Will

PS - thanks Nitroz, you were quicker with the reply

 

[Nitroz]

The first post has 3 videos where you see me moving the switch in operation on this mule/prototype - that is why I had that small piece of blue tape in the videos so that you guys could see the movement.

Once I have the second prototype (closer to final design), I will make new videos.

Will

I can't wait to see the finished product! It seems like nothing has really stood out in flashlights and then you come out with this. I love it when someone comes along with an innovation like this, it make everyone else work harder.

Your pictures, attention to detail, and creativity are amazing! Keeping an eye on this.

PS - thanks Nitroz, you were quicker with the reply

No problem.

 

[lucca brassi]

Nice work Will

that magnetodrive could be used also as throtle on scuba scooters ;-) special on brushless drives

 

[wquiles]

Nice work Will

that magnetodrive could be used also as throtle on scuba scooters ;-) special on brushless drives

That is a cool application :thumbsup:

 

[nbjly]

Definitely want to own one :bow: