Question for the saber guru's....is this possible?

[Kamurah]

Ok...what I was wondering...

Is there a way to take a momentery switch and use it on a latching board like the MR FX?

I have a Graflex hilt that has enough space under the red button for a very tiny micro switch...however; it is a momentary switch.

I would like to be able to hook up a MR board with it, but those boards require latching switches.

Is there such a thing as a "latching board" that could act as either a current regulator or to (even better) act as a latching switch once a momentary switch is activated inline?


If not...is there any way one could wire the hasbro board to pass current and act in this capacity (i.e. just act as a latch, and not use any of the electronics other than the switching)??

Thanks in advance for anyone who can answer this..

:)

[Steeljack]

Is there a way to take a momentery switch and use it on a latching board like the MR FX?

In a word, yes.

This sort of problem is easily handled by a small microcontroller. Watch for a momentary signal on an input pin, and flip the state of an output pin every time you see one. Easy, in principle.

There's a potential catch, though: things can get kind of noisy, electrically speaking, in that fraction of a second when the contacts of a momentary switch are actually touching. What feels to you like one quick press of a switch might actually look like a series of blindingly short presses to the microcontroller. The signal "bounces" a bit.

This is relatively easy to compensate for: add a little loop to the microcontroller so that there's a small but fixed increment of time -- say, a hundred milliseconds or so -- after one state change before it will permit another. The quasi-technical term for this is "debouncing".

Fortunately for you, someone has already done all the work of programming a microcontroller to this end, and will happily sell you one for $5: eLab (http://www.elabinc.com/Default.aspx?base), with its EDE 2208 (http://www.elabinc.com/Semiconductors/ProductOverview/tabid/57/Default.aspx). (See the last IC on that page.)

According to the spec sheet, the acceptable voltage range for the IC is 3 to 5.5 Volts, meaning that it should be perfectly happy with the 4.5 Volts used by a Master Replicas board.

(It occurs to me as I'm writing this that the above only holds provided that the Master Replicas board doesn't run any significant current through the switch -- that is, that the switch is merely providing a signal, and not expected to carry enough current to power the entire set-up. That would be far and away the sane way to design things, but I'd have to disassemble one of my MRs and poke at its board for a bit to find out, unless someone here happens to know.)

[Kamurah]

Steeljack....

Thanks for the info!

um.... now I show my ignorance....


What would I need to do to make that IC work?

I assume I would have to make some sort of board to house it, or solder it to a breadboard...but I have NO experience doing such a thing.


Again...Thank You for the response. :D

[Kamurah]

Nevermind...it always helps to RTFM.

It is autowired....I obviously do not understand IC's very well :)

Looks like it DOES pass current....so it is a current gate.

This would probably work...but I wouldn't get the power off sounds from the MR board.

hmmm......

[Kamurah]

Ok...so now the question becomes....


Does the latching switch on the MR board pass current?




Anyone?

Bueller?

Thanks to anyone who has a multimeter and can check this.

[Steeljack]

What would I need to do to make that IC work?[

Very, very little, I think. A simple little PCB, barely larger than the package itself. It would need a couple of contacts: two for power and ground to run the IC itself. One from the momentary switch to an input on the IC, and another from the corresponding output on the IC to the appropriate contact on the MR board. (This is assuming that you're running one contact from the MR board straight into the momentary switch. There are a couple of possible variations on the design, depending on how clever vs. modular you want to be.)

Which MR board are you planning on using in this saber? (That is, which MR saber was it originally from?) How much room have you got to play with in the hilt itself?


This would probably work...but I wouldn't get the power off sounds from the MR board.

D'oh! Actually, you just made me realize that I knew the answer to my own question all along, had I only had the presence of mind to realize it. Thanks for the nudge. :)

The current to power the saber can't be run through the latching switch itself. Otherwise, the saber would go dark the moment you flipped that switch to "off", instead of doing the smooth rampdown and playing the power-off sound.

This is good. It means that the latching switch is just there to send a signal, and that it ought to be possible to use a momentary-to-latching converter with the MR board.

Heck with it. My curiosity is now sufficiently piqued that I just ordered a couple of EDE2208s -- hey, they're cheap -- and will see if I can build the PCB mentioned above for them. If I succeed, maybe you and I can figure out how to mate one to your MR board.

[Kamurah]

Oh this sounds like fun! Count me IN!!!

So, if I get what you are saying....the MR board switch is just a signal only....and since the IC itself has it's own current tap (pin 5 I think from the schematic), it won't matter that the latching switch isn't in the current flow.....and therefore the setup might just work?

BTW, I'm using a 2007 vader board. (Yeah, I know I should probably use a light-side board, but I looked on all the tutorials and the Vader looked the easiest to disassemble.....lol) This is my first project.

It's going in an original Graflex 3 cell that I have setup as a Luke ESB replica.


If this works out, this would be a great alternative for us Graflex guys.....currently the only way to use the original Red button is to have an Ultrasound or Plecter board setup and use a micro switch sandwiched between the bottom of the button and the blade holder (BTW, I am going to buy one of Tim's or Erv's boards anyway...they are just not in stock now). Also, the latching "red button" setup sold at the Graflex shop is a (IMO) sloppy workaround and I do not like it. I prefer to keep as many of the original parts as possible.

With something like this, you could have a LOT more switch options for the MHS system too for all the MR users.

This is so neat....in the past I was too intimidated to try a project like this...but this stuff seems FUN!

Hey thanks again for all your help on this....I am really in your debt!


:D

[Marsupial]

keep us posted. I have non-latching corbin boards that would have a new use with some MR boards ;)

[Novastar]

gundamaniac had a momentary switch wired to the latching MRFX board, and it did indeed work.

Hopefully I do not have that reversed... but you may want to ask him, since it was his saber.

I *DO* know that you needed to "double-click" the switch for it to go on and off... and by leaving the switch clicked only once... current WOULD be flowing through the circuit and draining batteries... so you'd want to double-click it "right" every time.

Bloody 'ell. Reminds me of the James Bond movie where the computer geek is double-clicking the pen all the time... Goldeneye I think... :)

[Kamurah]

Thanks Nova...I will shoot him a message and see.

BTW....great performances /ideas on BOP.

Great sound editing too (my other obsessive hobby is sound engineering / recording / music composition). Must have taken a LOT of rehersal by the actors to time all the dialog / interaction with the blocking on onstage.

Cheers

[Jetsi]

Lots of good information in this thread.

Now what is the possibility of doing the opposite, running a momentary board, such as a Hasbro, with a latching switch?

If this was possible, a DPDT latching switch could power the board for sound and the blade with a Lux III/V or K2.

[Steeljack]

Now what is the possibility of doing the opposite, running a momentary board, such as a Hasbro, with a latching switch?

Like the momentary-to-latching trick, this should be a fairly easy job for a cheap and simple microcontroller. Watch an input pin, and remember the last state you saw it in. When its current state is the opposite of its last state -- meaning someone just switched the latch from off to on, or from on to off, send a pulse down the output pin.

I say this in theory, not having tried it yet. I did just get an Arduino (http://www.arduino.cc/) starter kit from Adafruit Industries (http://www.adafruit.com/), though, so now I have an incentive to get it set up and start experimenting. :)