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Optical hihat controller

PostPosted: Mon Dec 08, 2008 12:53 am
by elrules
I have seen the optical hihat controller in the edrum.info web. And I have some doubts.

Is that pedal on/off or is it gradual? As I can see when the pedal is closed the light does not reach the sensor, but when opened it fully reaches the sensor, so, for me, it seems that it is a 2-state pedal. Am I wrong?

I want to build a hihat controller more durable. With a slider resistor it is not very durable. The optical alternative looks good, but only if it allows gradual positions (open - halfopen, halfclosed, closed..)

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 10:07 am
by dmitri
It's actually variable. And much better than a design with a pot because it doesn't have moving parts. The only drawback I encountered was that photoresitors may be a bit slow to react so I used a sensitive photo diode/transistor. The output voltage of a optical HH is proportional to a current through a photo resistor/diode/transistor. The current through the photo resistor/diode/transistor is roughly proportional to amount of light hitting it. The amount of light hitting the photo resistor/diode/transistor is roughly proportional to how deep the pedal is pressed, provided the HH pedal has a good construction and achieves variable light blocking.

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 12:31 pm
by elrules
So, in the end, better to keep building a pot pedal...because it seems very difficult to build an optical (good-working) pedal.

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 12:46 pm
by dmitri
elrules wrote:So, in the end, better to keep building a pot pedal...because it seems very difficult to build an optical (good-working) pedal.

On the contrary, it is easier to build than a pot based pedal.

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 4:34 pm
by elrules
But how the hell can you show more to less light in a 2 cm track??
A common hihat pedal goes from open to close, and that range in terms of phisical cymbal movements is usually 2 cm. How can you make it gradual with a standard acoustic hihat stand?

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 4:51 pm
by dmitri
Does it make sense?
opto-sketch.JPG

Re: Optical hihat controller

PostPosted: Mon Dec 08, 2008 5:19 pm
by jamalpiper
elrules wrote:But how the hell can you show more to less light in a 2 cm track??
A common hihat pedal goes from open to close, and that range in terms of phisical cymbal movements is usually 2 cm. How can you make it gradual with a standard acoustic hihat stand?



By Scaling.

Re: Optical hihat controller

PostPosted: Tue Dec 09, 2008 12:53 am
by elrules
Damn it... how I didn't thought of that. Maybe I was only thinking in installing it close to the cymbal, like the VH-11 controller. This optical pedal needs to be installed on the pedal itself.

Re: Optical hihat controller

PostPosted: Tue Dec 09, 2008 1:13 am
by jman 31
I had a thought as to how it could go between the highhats. You could make a mini pedal type deal, with the bottom solid mounted to the lower cymbal. Then attach the top part of the thing to the bar that goes up and down in the middle. The photo switch could go on that. Just a thought.

That is, if you were converting an accoustic set! ;)

Re: Optical hihat controller

PostPosted: Tue Dec 09, 2008 3:37 am
by elrules
That is really smart!!

I will see how can I build it.