JohnRoberts

Bad design or isolated problem...
« on: November 11, 2019, 04:18:23 PM »
I am often discouraged by modern products that promise more than they deliver...

My fancy outdoor thermometer (with barometric sensor) claims to predict weather. It has been wrong far more often than correct despite a very forgiving 12-24 hour forecast window.  I would much prefer a digital barometer readout so I can use my own judgement.

===

My current trigger disappointment is a very "cheap" set of grow lights I recently purchased to stick inside  my cheap plastic green house I just moved into my laundry room to extend the growing season and get a head start next spring growing my hot peppers from seed.


But back to those grow lights. They were cheap because they left no corner uncut... 2x 10W LED strips powered from one 5V @ 2A USB power module (I can do that math in my head.  :o) )

But current consumption does not appear to be the problem.  The Achille's heel (look it up) for this USB PS seems to be low temperature.  It works as expected at warm temperatures, but during cold overnight dips (30's a few days ago), it got stupid. The LEDs blinked at a modest rep rate.

When I brought the PS inside and made measurements with my VOM on my test bench (apparently after it warmed up), it read a solid 5.2V.  The next morning (cold) when it was blinking again, I confirmed that the 5V supply was not solid 5V but pulsing.

I have a simple thermostat regulating a 60W light bulb in the bottom of the green house for heat (set for 50'). I used an extension cord to move the USB PS inside the heated area of the greenhouse. So far it has been working perfectly for over 24Hours. The controller dongle is pretty simple, 3 intensity settings and 3 on time duration settings. After you set it, it just repeats every 24 hours, and that part is working now inside the heated area.

Weather report is forecasting a freeze warning tomorrow night so we'll see.

===

To determine if this is an isolated failure I ordered another 5V USB supply. These are really cheap and I suspect they all use the same chip inside (just like all driveway solar lamps use the same chip). BUT that could explain my drama... these USB PS are basically intended as phone chargers and have "smart" protections built in to prevent phone batteries from causing house fires if oversharged.  :o

One theory of mine is that the low temperature is shifting an internal junction based voltage reference (high) making the PS think it is operating over voltage.  Or not, if the replacement USB PS works with no temperature sensitivity then I am clearly over thinking this (extremely possible).  8) 


 JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.


scott2000

Re: Bad design or isolated problem...
« Reply #1 on: November 11, 2019, 05:03:28 PM »
growing my hot peppers from seed.


Not to veer right off but, it's weird that this is the second time within a week I've heard about hot peppers......

My partner I work with is big into hot peppers and is almost done fermenting his Reapers for some sauce I've had dibs on for a while.(pic) ...

Then the other night my wife comes home with a spaghetti jar full of sauce one of her customers makes once in a while.. (Habanero, reaper, Caribbean red and scotch bonnet)  ....wow.....Fun stuff! Cool thing is that the crazy goes away after 15 minutes....

Not sure why I've been fascinated with heat lately but it sure makes eating a bit more exciting....

Good luck on your growing

JohnRoberts

Re: Bad design or isolated problem...
« Reply #2 on: November 11, 2019, 05:54:49 PM »
I grew habanera from seed the last two years, but this years crop did not make it...(operator error)  :-[,  next year will be better . I have a bunch of Thai peppers still growing in my green house, tiny but little heat explosions of capsaicin.  ;D

To veer from your veer, I have recently been experimenting with slow cooking at somewhat lower temperatures. I am surprised by how much difference cooking at 185' makes vs 200'. Unexpectedly the hot peppers are noticeably hotter when cooked at 185' even when cooked twice as long.. The vegetables do not shrink as much either, both good things. 

I now return you to geeky electronics stuff....

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

JohnRoberts

Re: Bad design or isolated problem...
« Reply #3 on: November 12, 2019, 10:55:35 AM »
My one 60W bulb was not enough heat to keep the USB supply happy over night. I have upgraded to a 3 x 60W fixture that should cut it, for "three dog nights".

I have a replacement 5V USB PS on order so I will find out if it is a personal problem or general design issue.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

PRR

Re: Bad design or isolated problem...
« Reply #4 on: November 12, 2019, 12:20:09 PM »
> upgraded to a 3 x 60W

Using 180 Watts of incandescent to keep 10 Watts of LEDs going??

Even being the wrong color and wasteful, you'd think the incandescents alone could grow the plants.

These grow-lights are above your price point but have worked well for us for 3 winters. They come in choice of light color. Free delivery.  But no cycle-timer. (I use plain old rotary-dial anti-burglary timers.)
https://www.homedepot.com/p/Feit-Electric-2-ft-2-Light-19-Watt-White-LED-Hydroponic-Non-Dimmable-Indoor-and-Outdoor-Linkable-Plant-Grow-Light-Fixture-Daylight-74303/206384743

JohnRoberts

Re: Bad design or isolated problem...
« Reply #5 on: November 12, 2019, 01:06:14 PM »
> upgraded to a 3 x 60W

Using 180 Watts of incandescent to keep 10 Watts of LEDs going??
Mainly to keep my pepper plants alive... 1x60W could not even keep a solid state switcher happy.  I already notice some leaves turning yellow, so hopefully the 3x60W will keep the temperature warm enough.
Quote
Even being the wrong color and wasteful, you'd think the incandescents alone could grow the plants.
I remain apprehensive about cheap LED grow lights, but they appear pretty proud of themselves.

Plants need warmer temperatures too.
Quote
These grow-lights are above your price point but have worked well for us for 3 winters. They come in choice of light color. Free delivery.  But no cycle-timer. (I use plain old rotary-dial anti-burglary timers.)
https://www.homedepot.com/p/Feit-Electric-2-ft-2-Light-19-Watt-White-LED-Hydroponic-Non-Dimmable-Indoor-and-Outdoor-Linkable-Plant-Grow-Light-Fixture-Daylight-74303/206384743
You growing pot in the basement?   8)

I am not expert but casual research suggests red and blue light spectrums needed. Red is easy for LEDs blue less easy but not as hard as it was in the past.

The grow lights were a cheap impulse purchase and the heated greenhouse with a window for sunlight exposure is the primary plan. Last winter a cold water pipe feeding my back yard water faucet froze up solid inside that laundry room. I now have heating tape wrapped around that cold water pipe. 

Last spring I sprouted a bunch of hot peppers from seed indoors on window sills, but mishandled the cold-conditioning to move them outdoors. Hopefully next spring's crop will be better (easier) managed, and have an easier transition.

If i can extend the growing season for my two remaining pepper plants (Bell and Thai), that is gravy.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

PRR

Re: Bad design or isolated problem...
« Reply #6 on: November 12, 2019, 11:06:20 PM »
OK, we run a 180W heating pad under the late-fall tomatoes in our cellar which may even be warmer than your laundry room. Incandescents are still your cheapest electric heat in hundreds-Watts size.

Yes the gro-lites come in several colors but I didn't pick them and have no clue what works best for what crop.

With my green-thumb(NOT!) it would make more sense to buy a "medical" green-card and buy pot than to throw dirt and get non-pot weeds. (I have a talent for crabgrass.) I really can't figure growing anything I can readily buy. (Special peppers are a possible exception: the stuff sold is shop-hardy, not the best and rarely fresh, and a pepper plant is not a whole room or garden-plot.)

JohnRoberts

Re: Bad design or isolated problem...
« Reply #7 on: November 13, 2019, 09:28:28 AM »
OK, we run a 180W heating pad under the late-fall tomatoes in our cellar which may even be warmer than your laundry room.
I had a cold water pipe freeze, but not burst in there last winter. I installed automatic heat tape, to prevent that water pipe freezing again.
Quote
Incandescents are still your cheapest electric heat in hundreds-Watts size.
Lows in the mid 20s last night outdoors. My greenhouse is a toasty 50' inside thanks to 3x60W incandescent heat. The grow light/USB supply was blinking again. I should probably leave it unplugged until my replacement USB PS arrives, but it rebooted this morning. 
Quote
Yes the gro-lites come in several colors but I didn't pick them and have no clue what works best for what crop.
same here...
Quote
With my green-thumb(NOT!) it would make more sense to buy a "medical" green-card and buy pot than to throw dirt and get non-pot weeds. (I have a talent for crabgrass.) I really can't figure growing anything I can readily buy. (Special peppers are a possible exception: the stuff sold is shop-hardy, not the best and rarely fresh, and a pepper plant is not a whole room or garden-plot.)
I do not have a green thumb either but like my hot peppers... I had some success growing habanera from seed the season before this, but managed to kill several hot pepper seedlings this spring. Thai peppers are my only surviving hotties from this season's crop.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

Re: Bad design or isolated problem...
« Reply #8 on: November 13, 2019, 03:58:12 PM »
Chillis are a fun crop alright , did them a few times in the greenhouse over summer , One year I got a bumper crop of wicked hot small birds eye chilli , I treaded them with a sowing needle an thread and dried them , lasted for ages
I keep the West Indian style hot sauce around for when I want instant flavour punch .


JohnRoberts

Re: Bad design or isolated problem...
« Reply #9 on: November 13, 2019, 04:23:41 PM »
Chillis are a fun crop alright , did them a few times in the greenhouse over summer , One year I got a bumper crop of wicked hot small birds eye chilli , I treaded them with a sowing needle an thread and dried them , lasted for ages
I keep the West Indian style hot sauce around for when I want instant flavour punch .
I still have some dried habanera in my cupboard for heat emergencies, I bought years ago on a road trip in the real world (still bring the heat).

I have seen fresh habanera in supermarkets in CA but not in MS (hey bubba chew on this).

---

My fancy Indoor/outdoor thermometer that thinks it can forecast weather, was wrong again this morning when it forecast snow...  Now it is forecasting rain.  :o

 Real weather forecast says 0% today, 50% tomorrow...  I could flip a coin and do better than this gadget.  ::)

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.


PRR

Re: Bad design or isolated problem...
« Reply #10 on: November 13, 2019, 05:17:20 PM »
> My fancy Indoor/outdoor thermometer that thinks it can forecast weather, was wrong again this morning when it forecast snow... 

It is perfectly accurate. We have the snow (1/4" of crusty ice). Your perception problem is that it is reporting for Maine and you think you are in Mississippi.

And if you are in the 20s and have Gulf Air, I'm sure it could snow. Eventually the too-fancy gizmo will call it right. Stopped clock is right twice a day. Jackson gets an inch of snow a year....
https://www.gannett-cdn.com/presto/2019/01/29/PJAM/e7b6b989-64e9-4da4-b85b-f0aa95525271-Snow_on_cars.jpg
The click-bait: Why does Mississippi have more snow than most of Upstate NY?
« Last Edit: November 13, 2019, 05:20:48 PM by PRR »

JohnRoberts

Re: Bad design or isolated problem...
« Reply #11 on: November 13, 2019, 07:14:03 PM »
> My fancy Indoor/outdoor thermometer that thinks it can forecast weather, was wrong again this morning when it forecast snow... 

It is perfectly accurate. We have the snow (1/4" of crusty ice). Your perception problem is that it is reporting for Maine and you think you are in Mississippi.

And if you are in the 20s and have Gulf Air, I'm sure it could snow. Eventually the too-fancy gizmo will call it right. Stopped clock is right twice a day. Jackson gets an inch of snow a year....
https://www.gannett-cdn.com/presto/2019/01/29/PJAM/e7b6b989-64e9-4da4-b85b-f0aa95525271-Snow_on_cars.jpg
The click-bait: Why does Mississippi have more snow than most of Upstate NY?
I've been here 35+ years so I have seen actual snow in my MS yard.... (once I had to clear it out of my satellite antenna with a broom).

But as a yankee I know what real snow is so I don't wake up the kids, and neighbors, to look at the "snow" falling  in my pick-up truck's headlights in the front yard in the middle of the night before the sun comes up and melts it.

Just like it's always beer o'clock somewhere, it's probably always raining or snowing somewhere. (I guess I need to check the fine print on that forecast.) ::)

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

JohnRoberts

Re: Bad design or isolated problem...
« Reply #12 on: November 17, 2019, 06:59:46 PM »
For everybody waiting for the rest of the story... I have determined that the misbehaving USB charger/PS was faulty and not a design problem. A replacement USB charger/PS has worked fine for a couple equally cold overnights.

I decided to perform a post mortem on the faulty USB charger/PS. It looked pretty well assembled (decent solder). There was one almost suspect solder joint on a diode in the HV section. I touched up that solder joint and gave it another night out in the box (laundry room). Again it failed during the overnight,,, so bad module with no apparent visible manufacturing flaw.

I searched the IC PN and found a chinese company website all in chinese. The USB charger/regulator chip is FT8371A from a chinese IC company HIENSEMI.. There was a pop up chat window with an attractive chinese girl offereing to answer questions (I suspect)  but i don't speak chinese either.

This reminded me of something I though about years ago... what if all we could buy to make audio products was chinese ICs and all the data sheets are only available in chinese.?  You think SMD is hard... try reading chinese.  :o

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.


 

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