Comments

Author Comment Last activity Moderation
donblair "Hallo! I haven't had great luck with Digikey shopping carts sticking around, so it might be better to put direct links to parts in e.g. a wiki ......" | Read more » almost 8 years ago
donblair "I need a little help understanding this background. When you modulate the LED at 1 kHz, that means it's flashing on and off 1000 times a second? E..." | Read more » over 8 years ago
donblair "@pdhixenbaugh -- These are great ideas / questions / suggestions! I just posted a quick follow-up here: https://publiclab.org/notes/donblair/03-2..." | Read more » over 8 years ago
donblair "Hah, just saw that @mathew posted a link I was reading this morning, but forgot to include: http://www.electroschematics.com/6923/555-low-voltage-..." | Read more » over 8 years ago
donblair "Yes -- at this point it might very well be possible to do temp, conductivity, and turbidity while only needing to put screws through the cap, and t..." | Read more » over 8 years ago
donblair "Thanks for all the good thoughts, wow! Chris -- I think you're right -- your experience and our friend Rui's experience is that most folks don't w..." | Read more » almost 9 years ago
donblair "OH. MY. GOSH. Amazing design (and video!!!). Can't wait to chat with you about this. Relevant electronics parts are being ordered presently. " | Read more » almost 9 years ago
donblair "Whee!! I understand the confusion re: K20! It's funny though, I figured most people would've confused it with: Antifungal amphiphilic aminoglyc..." | Read more » over 9 years ago
donblair "Oh, toilet tank analogy is great! @cversek was talking at LEAFFEST about how, in the water <--> electricity analogy, the only sticking point..." | Read more » almost 10 years ago
donblair "Aw, shucks :) But yes, it's so cool that we might find some part of design solution space that satisfies all of these! Before Ben pointing me to t..." | Read more » almost 10 years ago
donblair "Here's an example of a cheap, through-hole 'trimmer capacitor': http://www.amazon.com/Through-Trimmer-Variable-Capacitors-Brown/dp/B00G9BJTJW/ref=..." | Read more » almost 10 years ago
donblair "Ah darnit, I deleted my comment above by accident, instead of editing it ... Okay, the punchline is: The only ways to compensate for the effect t..." | Read more » almost 10 years ago
donblair "My endocrine system can't handle all of these ups and downs. But tonight ends on an up. " | Read more » almost 10 years ago
donblair "UPDATE: We can dial in the capacitance! Ben pointed me to the fact that 'trimmers' exist: http://www.mouser.com/ProductDetail/Murata/TZB4R500EA1..." | Read more » almost 10 years ago
donblair "Yes! And before, when we had a different relationship between freq and conductivity, the only way to do that tuning was to tweak the probe -- and J..." | Read more » almost 10 years ago
donblair "(maybe that should prompt me to reconsider my life direction?) " | Read more » almost 10 years ago
donblair "YES! :) I was dancing around with glee last night when I saw the equation for freq vs. resistance and capacitance for the 50% duty cycle! " | Read more » almost 10 years ago
donblair "Cversek -- wow, thank you!!! What a useful collection of info. Your note convinced Ben to add a dual op-amp to buffer the conductivity output, and..." | Read more » over 10 years ago
donblair "Just noticed -- in that last plot, it looks like the 'falling times' (top curve) start 'slumping', whilie the 'rising times' (bottom curve) seem re..." | Read more » over 10 years ago
donblair "And, as per our discussion elsewhere today, maybe we also want this material to go in a 'wiki' ... if you get a chance, Catherine, maybe you can d..." | Read more » over 10 years ago
donblair "Yay! " | Read more » over 10 years ago