Pressure Sensitive Resistors

[smallbearelec]

Just came in. See New Products:

http://smallbear-electronics.mybigcommerce.com/

These might be more interesting to the Synth community. However, I can also see possibilities for FX-related touch-pad controlled filters, distortions, etc.

[Mark Hammer]

Neat!

The SBE links to the datasheet appear not to work, so interested parties might try looking at this page for data: http://www.taiwanalpha.com.tw/english2014/p_e_008.htm

[J0K3RX]

Looks like the same one that "littlebits" is selling, saw it in Radio Shack and bout swallowed my tongue when I saw the price..  Of course, I will be buying from smallbear if I decide to get any!!

http://littlebits.cc/bits/pressure-sensor

[lapsteelman]

Awesome, I've been wanting to play around with those! I see an order in my near future  

[PRR]

Specs unhelpful. I suspect that if you press with one ounce you get a high resistance, with two pounds you get a lower resistance, but roughly what resistances?

[smallbearelec]

The SBE links to the datasheet appear not to work

Apologies, fixed.

[Frank_NH]

I can see using these for a DIY bathroom scale...complete with red leds illuminating if you're overweight.   

[newperson]

You might at least add the size of each unit within your text description.  Clicking on a link to go to a PDF if bothersome for many, especially if you are on a mobile device.  

Edit:
It is nice to see some more synth stuff.  That is a growing market.  Would like to see if you can find out who remade the Ua726 ICs and stock them.  They seem to come and go away often on eBay. 

[bwanasonic]

I can see using these for a DIY bathroom scale...complete with red leds illuminating if you're overweight.   

Just gave me an idea for a stompbox housing!  "Tone to DIEt for!"

[snap]

not alpha, but interesting read through product datasheet and integration guide!  http://www.interlinkelectronics.com/FSR402.php

[Frank_NH]

I can see using these for a DIY bathroom scale...complete with red leds illuminating if you're overweight.   

Just gave me an idea for a stompbox housing!  "Tone to DIEt for!"

Here's a related application.  Make a pad which the guitarist stands on, with the weight sensor underneath.  For every 1 pound overweight, the output to the amp is reduced by 1 db.   

Seriously, I can see some DIY drums made from a sensor like this.  Maybe a pad you could mount to your acoustic guitar's body for creating percussion sounds while you're playing.

[scratch]

got to be a way to use those with a rocker pedal???

[Mark Hammer]

They're probably useful for making clones of the EHX Soul Kiss.  The actual Soul Kiss uses an encapsulated LDR module, but there's no reason why it couldn't be substituted for with a sensibly-protected "bite pad", that simply replaces the LDR with the FSR.

And if you're going to use a "bite pad", why couldn't you have a pair of FSRs as part of a full-mouth bite pad, one for working the frequency and the other for working the Q.

Note as well that the resistance range is nicely suited to running the FSR in parallel with the 1M resistor that comes off the trimpot in a Phase 90.  That resistor partly sets the sweep range of the phaser (higher or lower).  Absolutely no reason why the 1M couldn't be subbed with 1M2, and the FSR in parallel so that you could bite your way to different phase tones from gurgly to swirly.

https://www.youtube.com/watch?v=1nU9mFkxfUY

[smallbearelec]

I recall a 70s circuit: Twin-T oscillator with the gain clamped below the feedback point. You would "ring" it briefly into oscillation by touching a metal plate that was wired to the right part of the circuit. I wonder what would happen if you subbed an FSR for one of the resistors in the Tee ?  I hope someone will check this out. I can't...too many other projects.

[Processaurus]

Neat item to stock!  I believe FSR's are what are used in MPC type drum machine triggers, instead of piezo's.



I wonder if anything more special than a rubber pad glued over the top would be needed to protect for a foot control, where you just kinda mush it with your foot.

[mac]

They are nice for wahs, no more scratchy pots

mac

[puretube]

...
I wonder if anything more special than a rubber pad glued over the top would be needed to protect for a foot control, where you just kinda mush it with your foot.

YES...



(just be sure to have a small "actuator" - e.g.: a washer - between the FSR and the pad)
(or have some "profiled" flipside of the pad...)

[Mark Hammer]

How quick do these thing respond; both to pressure applied, and pressure released?  Are these faster than LDRs?

[puretube]

Faster than LDRs.
I`d say: immediate response...
But than again: turning a pot takes some travel time, too - it doesn`t "jump" from one value to the next...

(And: on another hand, I used the FSR to "immediately" control the LED-current through LEDs lightening up multiple LDRs,
so the response slowed down, again...  )

Smallbear got a good price on those... (17 years ago, they were like 12 bucks...)

[Mark Hammer]

Thanks for that, Ton.

Yeah, the price really HAS come down.

If a person could figure out a way to simultaneously apply equal pressure to a pair of them in a SVF, that would make a really easy foot-wah.