Thanks Louis, that is most helpful and comprehensive.

Cheers

Ron B

An interesting post that got me thinking about these components as switches. Your link shows that there are quite a range of contactless switches svailable, so I suppose my query is general to all of these, although specifically to the cheap Hall effect switches readily available.

My query is this: do these switches suffer from 'bounce'? That is  do the need to be denounced when integrated into a mcu design?

Just wondering....

Regards

Ron B

@ronbentley1, Good question Ron, but no, since they are essentially contact-less, that eliminates the "bounce" that is caused by physical contacts. I guess one way of visualizing it would be to consider the contacts on a physical switch as leaf-springs, so when depressed and released, they tend to vibrate which causes the multiple contact you most likely encounter. The solid state has no contacts..hence, no bounce. Another feature of solid state over physical switches is no contact arc..That is the reason why with high voltage, that modern circuit breaker controllers use vacuum breakers to suppress the arcing that happen when the contacts open.

While this is off topic, I have provided a link to show what vacuum breakers are: https://new.siemens.com/global/en/products/energy/medium-voltage/components/vacuum-circuit-breakers-for-special-applications.html

so you can can understand why this is important. For our discussion, there are many ways to eliminate contact bounce, and solid state is the way to go. programming in de-bounce routines work on very low voltage-current application, but will not protect the physical switch from arc flashing..remember in the old days before electronic ignition in cars & trucks, when we had points & condenser?  that was the job of the condenser ( ie: a capacitor) to suppress the arc when the contacts opened. Hope this helps with your understanding of how this all works..

regards,

LouisR

An interesting post that got me thinking about these components as switches. Your link shows that there are quite a range of contactless switches svailable, so I suppose my query is general to all of these, although specifically to the cheap Hall effect switches readily available.

My query is this: do these switches suffer from 'bounce'? That is  do the need to be denounced when integrated into a mcu design?

Just wondering....

Regards

Ron B

SP

@inst-tech Along those same lines in woodturning we say, "Never take that last cut." Why? Because that's always the cut when you go through the side or the bottom or have a big catch, all of which destroy the piece. Once one is proficient, that doesn't happen too much, but it is always there waiting for you to misjudge the depth of cut or thickness of the material. It is often tempting to make just one more cut to get some minor imperfection out that would probably sand out, only to misjudge something and have a complete failure. It must be said that at least failures on the lathe are normally pretty spectacular. Some great stories come out of those failures. :-0

Regards,

SP

As someone in the engineering game building many automated machines, I recommend proximity sensors,  

https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311&_nkw=proximity+switch&_sacat=0

@frogandtoad, @pritchs

Indeed frogandtoad..I agree, as I too have alot of experience with machine automation..about 40 years worth...lol

The problem is that there are many different types of proximity sensors, with their advantages and disadvantages.  I've included a link for @pritchs, https://www.linquip.com/blog/types-of-proximity-sensors/ that describes those in detail..this may help him to decide which way he would like to go..

Regards,

LouisR

@inst-tech Along those same lines in woodturning we say, "Never take that last cut." Why? Because that's always the cut when you go through the side or the bottom or have a big catch, all of which destroy the piece. Once one is proficient, that doesn't happen too much, but it is always there waiting for you to misjudge the depth of cut or thickness of the material. It is often tempting to make just one more cut to get some minor imperfection out that would probably sand out, only to misjudge something and have a complete failure. It must be said that at least failures on the lathe are normally pretty spectacular. Some great stories come out of those failures. :-0

Regards,

SP

As someone in the engineering game building many automated machines, I recommend proximity sensors,  

https://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311&_nkw=proximity+switch&_sacat=0

Regards,

SP

From this discussion, I'm going to try photosensors. They seem to be the least trouble. But then again, that's why I went the Hall switch route. 😀 The limit switches are the last major hurdle I know about, so it ought to go relatively quickly from this point. But who hasn't thought THAT before? 

Thanks again.

SP

@@pritchs,  Yep..I have always ascribed to the K.I.S.S. method.."The limit switches are the last major hurdle I know about, so it ought to go relatively quickly from this point. But who hasn't thought THAT before?"  indeed..and we have all done just that !... That's why we always said in the business, "There's nothing I can really do in less than an hour! LOL....  You just never know what your going to get into until you actually start.. then all the little gremlins come out to play, reeking havoc on your "well thought out project"...

One thing is for sure, that's half the fun of building something, and the other half is the satisfaction of it actually working!..

Be safe, and have fun..

regards,

LouisR