For an M2, switching back to Low, it is about 50 us. I wouldn't expect an X2, or switching to input (tri-state), to be very different. For better accuracy you'll probably have to measure it (with a pull-down resistor).how long is Drive_Pin held HIGH?
INPUT, rather than
LOW, like @wapo54001. (I also used
I have experimented with LDR volume control circuits but never achieved smooth control. Please keep us updated with your progress and share any schematics. I have used PWM to control the LED in the LDR and it worked reasonably well. My other plan was to use a very precise D/A converter and control the LED brightness by varying the voltage.In my opinion, an LDR-based volume control sounds far better than a simple pot or even a stepped attenuator.
My circuit uses four LDR devices to simulate a stereo volume control which requires each LDR to hold a very specific resistance. I use a Picaxe to control the current to each device by setting an output pin either high or low or off to adjust mosfet drive, and a second input pin to measure the actual current flowing through the LDR-mosfet combination to provide feedback. The goal is to achieve a perfect 25K or 50K logarithmic resistance curve stereo volume control using current with values ranging from 10ma to vanishingly small. Also, the LDR resistance curve is nonlinear.
premelec,FWIW note that LED brightness is better controlled with current rather than voltage.... an op amp and MOSFET converted a DAC to current output [I used 2 LM324s and 8 2N7000 in 8 channel DAC conversion units I made - serial from 08M2 to DAC].
JulianE,i am also starting to have serious doubts about my hearing acuity, shocking how difficult it is to hear slight differences in sound, i was convinced that there was a massive difference between tube (valve) audio and solid state, i went and built an AB comparison switch and the difference was very slight. on the other hand the difference between digital and vinyl is obvious, well made vinyl bests and digital audio format. i still listen to a lot of digital files, it's just too convenient.
that's phenomenal, i have tried my own LDR volume control and couldn't tell much of a difference from an Alps pot. I have a very good system but nothing spectacular, other than the Dynaudio speakers. I'm sure my hearing has tapered off with the passing years. I hope you do well selling your well thought out design.when I inserted this circuit in lieu of my high-end Yamaha preamp, but I was blown away by the new transparency.
LOL! I have about twenty circuit cards that have been sitting in their static-proof bags all this time. My heirs will probably have to dispose of them when I'm gone.that's phenomenal, i have tried my own LDR volume control and couldn't tell much of a difference from an Alps pot. I have a very good system but nothing spectacular, other than the Dynaudio speakers. I'm sure my hearing has tapered off with the passing years. I hope you do well selling your well thought out design.
Really impressive setup. What I find daunting, though, are my mother's dozens of carousels of slides and the need, with the gear I've looked at, to do each slide individually. And I'm supposing that no one is going to be very interested in photos of bears from our trip to Yellowstone Park in 1959.Now, I'm really into making superb digital copies of positive and negative film images for people of my generation who want to pass on their history to their children
"Traditional" (analogue) 'scopes were rarely used for "precision" (voltage) measurements, the "Deflection Sensitivity" of the CRT, and parallax to the graticule in front of the screen just could not allow high resolution/accuracy measurements. It was "difficult" to generate around 10 kVolts (for the CRT) with better than 1% accuracy, and good quality (analogue) meters had a mirror in the scale behind the needle to avoid parallax. Various "bells and whistles" were added for oscilloscope time measurement (e.g. a second, delaying timebase and ten-turn "vernier" pots, etc.), but still not comparable in accuracy to a dedicated (pulse) timer/counter or a Logic analyser.Perhaps another forum member with more experience with oscilloscopes could give you a more definitive answer.
Before SIGLOK was developed, those (remarkably good) little USB Logic Analyser modules originally used to "hijack" the Excellent (and User-friendly) software developed by the American company SALEAE. I don't know if Saleae managed to "protect" their software/IP, but they now appear to have moved on to adding Analogue channels to their (moderately-priced) hardware, i.e. drifting into Oscilloscope territory rather than Vice-Versa. The SIGLOK software seems quite "competent" with more features than you're ever likely to need, but I do still find myself hankering after the "elegance" of the original Saleae User-Interface. For best results, you do need a mouse with a scroll wheel.I just noticed this post, I will have a look, thanks. I guess the main question is what will the software do . . . .
Young(er) people are no longer interested in family heirlooms or family photos, but people of my generation are still pleased to hand digitized photos on, they consider it a duty accomplished. When my wife and I massively downsized via online auction, the auctioneer started the conversation by saying "You can either get rid of your stuff, or you can make some money, but you can't do both." It was true; younger folks travel light and don't accumulate what they can't carry on their back.What I find daunting, though, are my mother's dozens of carousels of slides and the need, with the gear I've looked at, to do each slide individually. And I'm supposing that no one is going to be very interested in photos of bears from our trip to Yellowstone Park in 1959.
It appears that hearing aid batteries are on their way out. A friend has told me about a hearing aid that you simply place on a wireless charger overnight and you're good to go in the morning. No battery replacement.and this has led me to think about making a hearing aid headphone setup rather than fiddling with expensive easily lost tiny amplifiers with short battery life... ;-0
i rather like it when the conversation meanders a little. This board is full of brilliant polite people, everyone brings something to the party. I have dedicated film scanners, i was so worried about demise of film that i have 4 film scanners in stock. I have also filled a refrigerator with enough film to last me the rest of my life, the refrigerator has a picaxe temperature sensor that transmits the temperature to a PC that is web accessible.Really strayed from Picaxe here, sorry!
And you DO have that backed up to at least two other locations, right??!!I'm still working on digitizing images from my family and my wife's family, some going back to tintypes and the like. Currently near 100K images on the 2GB drive on the tower computer and so far, only 10K or so of those in a database where content can be searched by person's name, place, date, event, etc.
Maybe you are too far along to change horses, but many of us have given up on "scanners" -- far too slow -- and gone the route of the dslr with commercial or homemade slide copying setup with a backlight to photograph negatives and slides. A dslr achieves 4000dpi -- the scanning gold standard -- at 24 megapixels which is pretty inexpensive today. The 1:1 macro lens to provide superb resolution will be a bit more . . .II also have a slide scanner but haven't yet started on those...