Bouncefree switch question.

[jpm83]

Hi I'm in process of building a winder for my self to start making some pickups for myself.
My question is that will this boucefree switch idea work on calculator or "step counter" (thing that counts your steps when you're walking), that is presented in this page. http://europa.spaceports.com/%7Efishbake/ot1/ot.htm

Janne

[R.G.]

Why don't you use an optical interruptor? No mass, no reversal of direction of a mass, and so no bounce.

[jpm83]

Thank's for answering. The reed relay thing just would be the most "easy" for me to put in this winder I'm making, but I'll have to keep that optical thing on my mind too.

[Joe Gwinn]

Thanks for answering. The reed relay thing just would be the most "easy" for me to put in this winder I'm making, but I'll have to keep that optical thing on my mind too.With reed switches, the usual problem is that the on time is too small a faction of the circle, causing the pulsewidth to become too narrow to count reliably at high speeds.

For example, a simply flying magnet will have an on time (duty cycle) of 1%, so if the counter requires 10 millisecond or wider pulses, the max speed is 60 rpm. People have had this problem with reed switches.

The solution is to arrange the magnetic circuit so that the on time is at least 25% of a rotation.

[DrStrangelove]

With reed switches, the usual problem is that the on time is too small a faction of the circle, causing the pulsewidth to become too narrow to count reliably at high speeds.

The solution is to arrange the magnetic circuit so that the on time is at least 25% of a rotation.Alternatively, use a Hall Effect switch from Allegro. They aren't much more complicated than a reed switch.

The A3245 isn't picky about magnet orientation or supply voltage.
http://www.allegromicro.com/en/Products/Part_Numbers/3245/index.asp

-drh

[Joe Gwinn]

Alternatively, use a Hall Effect switch from Allegro. They aren't much more complicated than a reed switch.True, but they require power, whereas a reed switch can be connected directly to a battery-powered counter such as a CUB3. If one has power, one can as well use the photo interrupter approach.

The simple way to arrange the flying-magnet cum reed switch is to have two parallel mild steel plates between which the magnet swings, the magnet being oriented perpendicular to the plates and parallel to the rotation axis, with the reed switch bridged between the two plates. The plates can be made from electric-box covers from a hardware store.

If the magnet is between the plates between 1/2 and 1/3 of a turn, the counter will work to ~2000 rpm, at least in theory. At very high speeds, it may be useful to make some radial slits in the plate to reduce eddy currents. Radial slits are on lines that pass through the location of the reed switch. I would not bother cutting the slits unless there is an observed problem, though.

[RedHouse]

Why don't you use an optical interruptor? No mass, no reversal of direction of a mass, and so no bounce.


+1

After you get a handle on how to use them, there really is no substitute.

[chevalij]

I have a basic schematic for wiring up the H21L0B opto switch if anybody wants it. I just use a divider network and a 9V wall wart to power it.

[David Schwab]

Here's how the Schatten does the optical counter. The optical devises are on the back wall.

[Joe Gwinn]

Here's how the Schatten does the optical counter. [Image deleted.] The optical devices are on the back wall.It strikes me that the small hole in the black disk may cause the pulsewidth to be too small, although counters vary and one assumes that Schatten picked a suitable counter.

[RedHouse]

...It strikes me that the small hole in the black disk may cause the pulsewidth to be too small....

Yes, that was a concern of mine when I made my 2nd winder, so I made sure to have like at least 25% of the optical wheel transparent. The CUB counters (I use) utilize a Schmidt trigger input so I don't have to worry at all about too wide a pulse.

Here's my micro-blog on it: http://users.isp.com/brad_anne/winder.htm

BTW, I too can provide some schem'a for the optical interruptor unit I used in mine (OPTEK OPB380) just ping me if you need it. In fact if I get any more than one inquiry I'll put it on my micro-blog. (my new term for pictorial info pages)

[RedHouse]

Here's how the Schatten does the optical counter. The optical devises are on the back wall.

Hey David, off-topic here, but do you take off-line questions about Bass pickups?
(email)

[jpm83]

I think that i will use that hall effect switch on this winder. Would this swich be usable for winder? http://pdf1.alldatasheet.com/datasheet-pdf/view/168556/ALLEGRO/UGN3130LL.html
UGN3130.
Thanks for all the replies.

Janne

[jpm83]

Or would this be better? http://pdf1.alldatasheet.com/datasheet-pdf/view/45869/SIEMENS/TLE4935L.html

Janne

[David Schwab]

Hey David, off-topic here, but do you take off-line questions about Bass pickups?
(email)

Sure. You can either email me or send me a PM via this forum.

[Joe Gwinn]

I think that i will use that hall effect switch on this winder. Would this swich be usable for winder? http://pdf1.alldatasheet.com/datasheet-pdf/view/168556/ALLEGRO/UGN3130LL.html
UGN3130.Hall switches work well, but one still has to ensure that the duty cycle isn't too small (pulses too short at high speed) for the chosen counter.

I found the alldatasheets website to be a nuisance. A simpler source for datasheets and the corresponding application notes is the manufacturer: http://www.allegromicro.com/en/. It turns out that 3130 is discontinued, but the data sheet is still available.

[jpm83]

I found the alldatasheets website to be a nuisance. A simpler source for datasheets and the corresponding application notes is the manufacturer: http://www.allegromicro.com/en/. It turns out that 3130 is discontinued, but the data sheet is still available.

My local electronics supplier have that hall sensor and they have those TLExxxx sensors also. That would be the place where I'm going to buy my pick up parts too. Thanks for the reply.

Janne

[RedHouse]

Sure. You can either email me or send me a PM via this forum.

Done, thanks.

[John_H]

I built this switch for my old winder. I've been using a reed switch with a decade wheel that is hooked to a pedometer. It works ok, but I thought it would be a big improvement to switch it to optical. I built this from Radio Shack components for less than ten dollars.

The photo transistor triggers a reed relay. When using a calculator or pedometer you only need to close the switch to get a count, so there is no load on the relay. It should last a while. Time will tell.

I tested it with a wheel mounted in a cordless drill, and it worked fine up to 1400 rpm which was the maximum speed of the drill. I'll trim the circuit board down before I mount it to the winder. It seems like it will work well.

Simple, cheap, and no bounce.

[jpm83]

I just ordered this counter. http://www.velleman-kit.com/downloads/0/illustrated/illustrated_assembly_manual_k8035.pdf
What do you think is this a good choise? I think I'm going to wind mostly guitar pickups.

Janne

[RedHouse]

I just ordered this counter. http://www.velleman-kit.com/downloads/0/illustrated/illustrated_assembly_manual_k8035.pdf
What do you think is this a good choise? I think I'm going to wind mostly guitar pickups.

Janne


I like the ease of the Up/Down arrangement, looks like a SPDT switch will do the trick.

[Yves]

I just ordered this counter. http://www.velleman-kit.com/downloads/0/illustrated/illustrated_assembly_manual_k8035.pdf
What do you think is this a good choise? I think I'm going to wind mostly guitar pickups.

Janne

It seems to have the features your need for pickup winding:
- between 120 rpm and 12000 rpm: largely more than you need
- preset value: handy if you want to automatically stop the winder at some preset number of turns with the use of some relay
- 4 digits (some will argue that 5 is better, but even in the event you are going above 9999, you can still keep the 5th digit in your mind, that's not that much to remember;) ... OK, you will loose the preset feature thing in that case)

Just need to add a proper switch, I personnally am in favour of opto switch.

I like the ease of the Up/Down arrangement, looks like a SPDT switch will do the trick.

RedHouse: what does "SPDT" stand for ? Thanks.

[RedHouse]

...RedHouse: what does "SPDT" stand for ? Thanks.

Your kidding me right? if not, I'd be happy to explain.

It is a (old) technical term which describes a switch type regardless of it's make or configuration. It is terminlology an electrician, an electronic technician and many other folks would use to describe switches (normal folks should too really).

It is an acronym we use in the USA and UK, I imagine the European DIN spec may call it something else.

I will elaborate if you please... What would you call a normal ON/OFF switch?

I would call it a SPST switch which stands for SINGLE POLE - SINGLE THROW see the pic below:

http://users.isp.com/brad_anne/guitar/Switch_types.jpg

The example at the top of the pic is a ON/OFF switch, technically it's a SINGLE POLE - SINGLE THROW switch.

The second pic is commonly referred to as a "toggle" switch because it toggles between two terminals, but technically it's really a SINGLE POLE - DOUBLE THROW switch.

The third pic is called a DOUBLE POLE - DOUBLE THROW switch. In the guitar pickup world, it it commonly used for Series/Parallel switching.



This schema can be expanded-out ...as necessary.

Hope this helps.

[Yves]

Thanks Redhouse.

I am not kidding you: sure I know what is a switch, but due to the language, I am sometimes missing things lexically speaking.

This is clearer now.

Yves.

[RedHouse]

Tres heureux de vous aider mon frere

(I hope that makes sense, I used Babel Fish to translate) ;)