somebody stop me

Relax in southern comfort on the east bank of the Mississippi. You're just around the corner from Beale Street and Sun Records. Watch the ducks, throw back a few and tell us what's on your mind.
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JR.
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somebody stop me

Post by JR. » Sun Jun 09, 2019 12:03 pm

The curse of being a design engineer is that almost every product we encounter is an opportunity to do it better. In most cases after spending too much time and money on a DIY project I found better commercial solutions.

My peltier based slow cooker project, gave way to power resistors for heat when the peltier heat source was impractical. After foregoing the peltier technology a commercial solution was easily superior.
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#1 even my lowly driveway lamp was one such example.
DSCF0084 copy.JPG
The opportunity presented itself when I had spare parts from tired broken, too cheap to fix soldiers. Long story short, I cobbled together a second solar panel from a broken lamp. Put in a larger capacity storage battery. I also cascaded two of the charge pump inductors in series to reduce the on current draw and extend over night light hours. This franken-lamp successfully negotiated the short days, long nights late last winter.

I did not expect this to survive this long (several months)... The two solar panels in series should well exceed the design voltage for the control chip, battery, etc....

Since it is still working my only question is should I retest this experiment to light both sides of my driveway. (I have enough spare parts). During the summer months my stock lamp seems to work fine.
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#2 digital TS-1... So far i resisted redesigning my iconic TS-1. The feature creep from discussions here put the nail in the coffin, for me... KISS.
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#3 Control front end for my surround sound system. I am so pleased with my upgraded Hypex amps, I wouldn't mind playing back stereo sources (might even dust off some old vinyl), but not only do I need volume controls I need some way to get 2 channel to feed 6 speakers seamlessly. I still have one of my old kit surround decoders from back in the early 80s, that covers all but the sub out, but don't feel like sending audio through a BBD delay in 2019.... The technology has moved so much I could probably just about make a digital delay using a single micro... I have a DSPic with 2x16b DAC built in... I could just about get by with built in 12b A/D but a cheap 16b stereo A/D is all of $1 BOM hit .

I could likewise craft a simple filter to steer a sub output while scrubbing low bass from primary L/R channels.
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Somebody stop me....

JR

PS: The cheap digital decoder has been working perfectly since I replaced the optical cable with a new one several days ago, but I have low expectations that this is the ultimate fix... :lol:
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

billshurv
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Re: somebody stop me

Post by billshurv » Sun Jun 09, 2019 3:08 pm

As the old joke goes. You know you are an Engineer when you try to fix a $5 radio!

The surround issue, as I have said before is one that is causeing me concerns and I'll probably end up buying a marantz decoder as it has L/R and sub analog outputs which I need. Prepros that have all the features I want are silly money. Sigh, damn Dolby et al and their licensing schemes.

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JR.
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Re: somebody stop me

Post by JR. » Sun Jun 09, 2019 6:47 pm

It is especially hard for me because I designed one myself back in the early 80s (not rocket science). I even had a handful of real movie theaters using my kit to playback dolby encoded movies, but don't tell Ray... :lol:

I just looked again today and probably a couple $k for just a decent A/V pre... now that's obscene. :roll:

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

billshurv
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Re: somebody stop me

Post by billshurv » Mon Jun 10, 2019 4:32 pm

Particularly galling for me because I have a miniDSP for the L/R channels so would prefer those to be digital. I guess I could set my player to do L/R out of the SPDIF output and slurp the rest off the HDMI using one of these https://www.minidsp.com/products/ht-series/nanoavr-hda . I do have an offer on an 8 channel volume control that would allow me to do volume duties, but not even sure if I want surround channels at home but I do want centre and I can matrix that old skool.

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Re: somebody stop me

Post by JR. » Wed Jul 03, 2019 2:03 pm

I don't want to start yet another thread for this, but one new iron in the list of projects fire and some old ones.

1- Ever since I bought my big dog 44" zero turn mower I was struck by how it can take only 20 minutes to mow my entire one acre yard, but a full day plus to do trim and mow the ditches. During rainy weather i can't even mow close to my side-back rain ditch where the muddy gradual shoulder can spin the fat tires and get stuck in soft mud... The front ditches are more stable but too steep for me to mow with the big dog... Years ago before the state trenched out the ditch so deep and steep, I could mow with my riding snapper, mowing up and down the ditch walls but not now.

The perfect tool is a farm tractor with a bush hog on an articulating arm. They even make dedicated ditch mower accessories for tractors but these are a couple grand each not counting the tractor. We already know I'm cheap, and think I can invent stuff... :lol: My proposed solution is to tow my 22" mower along side my big dog, offset a few feet to one side to allow it to cut my ditches while I remain safely on dry/stable ground.

The plan so far is to bolt a steel u-channel (actually a sign post) to the front of my mower with a couple of existing bolts. I can attach my small mower to this pull bar with some wire rope cable at the front wheel axels. The flexible wire rope would allow the small mower deck to follow the topology of my ditches. A third cable attaching the small deck from the back, allows me to back up, and prevents the small deck from tilting sideways and falling too far down into the ditches.

I would like an easy fast attach/release and might be able to do that already with the wire rope attachemnt lines, but the front pull bar appears semi permanent. I might start with a short length bolted to the big dog, then another length of longer u-channel attached to the short piece of u-channel. The bolts holding these together would be easily accessible. At some point if this actually works I might come up with some quick release pins, like the hoods on race cars use.

Even if this only allows two or three 22" passes into the ditch, that could save me hours of hand mowing.
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2- and old project rose up to the surface again when I had a new realization. A couple years back I stalled on my DSP based next generation drum tuner development when I had difficulty extracting phase from my assembler FFT code (needed arctan and more). I could successfully measure level from the FFT and was well on the way for a quick full drum scan... I was able to generate 10 or more clean sine waves simultaneously using the built in 16b DAC. Then with FFT I could identify major resonances and iteratively zero in on fundamental and lug overtone in seconds.

I needed phase for my "clear" function that fine tweaks the lugs to each other. My epiphany was that I didn't need to measure phase and pitch at the same time. Clear is measured with a steady tone so that doesn't even need dsp. That is the good news, my software coding roadblock was in my mind, the bad news remains that drummers are unworthy. They still think my current drum tuner is too expensive so are unlikely to embrace an improved even better one.

I may still do it, just because i can, but I am old and tired, getting older every day. 8-)

JR

PS: I noticed last night around midnight that my stock driveway lamp was already out, while my franken lamp was still burning bright. I probably need to go ahead and make a second franken lamp (I have the parts)... if it was going to blow up, it would have by now.
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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Re: somebody stop me

Post by JR. » Thu Jul 04, 2019 12:15 pm

DSCF0177.JPG
for the picture is worth a hundred words here is rough layout.

I can bolt the steel u-channel to the front bracket. I will use a single length of wire rope looped through a hole in the pull bar and grabbing the small mower at each front wheel axel attachment.

The single back attachment wire rope will connect low on the big mower, and high on the small mower push handle, so it will tolerate height differences in the ditch. If the small mower gets pulled a little sideways the grass/weeds should not complain.

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my steel u-channel has already shipped, and I have more than enough wire rope and crimp ferrules on hand from repairing my weight machine (that I don't use since my knee went arthritic).

I could get this puppy working by next ditch mowing session, or find out what I got wrong. :lol:

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

billshurv
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Re: somebody stop me

Post by billshurv » Thu Jul 04, 2019 4:12 pm

That reminds me of mowing my Dad's front lawn, which is on a fairly steep slope, and for which he used a gas flymo which is the most dangerous and evil thing ever as it has no blade shut off other then killing the engine and will happily slice through bricks without missing a beat (note this model now banned). No freaking way was I walking down a slope hanging on to that. So I got a reel of wire from the garage and sat at the top lowering it down and pulling it up. I had been scared of that mower from an early age, even before a neighbour borrowed it and chopped half a toe off.

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Re: somebody stop me

Post by JR. » Thu Jul 04, 2019 7:26 pm

One of my HS friends has a brother with a finger cut short by a lawnmower... his fingernail grew out of the back side of his finger... At least he had a story to tell girls.

I try to respect mowers... I have to defeat the dead man switch on the small mower to tow it... but I'll be careful. 8-)

Speaking of being careful, tonight I was cutting vegetables for my 4th of July Pizza feast. After a few beers, I slipped and put a little too much of "myself" in that pizza. :oops: I dosed it with some hydrogen peroxide before applying a band aid to plug the leak. It should knit up, but I need to be more careful about cutting vegetables after several beers.

In my experience the sharper the knife the safer, but stuff can still happen.

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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JR.
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Re: somebody stop me

Post by JR. » Fri Jul 05, 2019 1:14 pm

I just modified my other driveway lamp for franken-mode...

Now with 2x solar cell in series it will get more charge and turn on later at night.I swapped out the stock 300mAH battery for 600mAH. I did not put the two inductors in series for less light current draw. Ideally I'd like to try something less severe than half current, but do not have an easy way to measure the stock inductor.

The TH inductor is marked orange, orange, black, silver... so perhaps 33 micro-henry, 10%

Image

Looks like the picture in digikey... Two in series is like 66uH so I would like to try 47uH

This is the closest looking 47uH
Image

Lets see how it goes tonight... starting out with a hot charged battery and 97' this afternoon will be a good test for the battery. :lol: If it still goes dark too early, I'll revisit the inductor... two in series works, but a little brighter would be a little brighter. 8-)

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

billshurv
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Re: somebody stop me

Post by billshurv » Fri Jul 05, 2019 3:33 pm

Sounds like a perfect application for a TL431...

...I 'll get my coat

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