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Re: home improvement turns into science fair projects?

Posted: Sat Nov 09, 2019 7:31 pm
by JR.
mediatechnology wrote: Sat Nov 09, 2019 5:15 pm
small market
I call bullshit: https://www.amazon.com/universal-ac-dc- ... dc+adapter
Back at ya... The 5V @ 2A USB PS is $0.50 from alibaba, that puppy is not there.

But you go for it...

[edit my "small market" comment was WRT
Wayne wrote:"Not for technically illiterate but OK for some of us."


still a modest market for technically competent /edit]
===

I still think making audio gadgets run from 5V is less crazy with modern low noise ICs.

JR

Re: home improvement turns into science fair projects?

Posted: Sun Nov 10, 2019 8:28 am
by JR.
Well now I have entropy going in two different threads. :lol:

The grow lights are blinking again, so the evidence suggests a possible low temperature connection to the fault (overnight temps in the 30's again). I can imagine a really cheap VR have poor voltage regulation at low temp from lack of temp compensation for reference, but just speculation.

A little later when I warm up I will carry my VOM out there and try to measure it in place. It might be interesting to see if it starts working again on its own after it warms up? I may replace the PS anyhow because they are cheap (not $0.50) but low single digit dollars.

At least the old school (electro-mechanical) thermostat works reliably.

JR

Re: home improvement turns into science fair projects?

Posted: Sun Nov 10, 2019 9:36 am
by terkio
JR. wrote: Sun Nov 10, 2019 8:28 am

At least the old school (electro-mechanical) thermostat works reliably.
I love the old one with the curved glass tube mercury switch and the coiled bi-metal spring. 1930 clever technology.

Re: home improvement turns into science fair projects?

Posted: Sun Nov 10, 2019 10:47 am
by JR.
terkio wrote: Sun Nov 10, 2019 9:36 am
JR. wrote: Sun Nov 10, 2019 8:28 am

At least the old school (electro-mechanical) thermostat works reliably.
I love the old one with the curved glass tube mercury switch and the coiled bi-metal spring. 1930 clever technology.
Sorry just low tech bimetallic strip but works...

I just put a meter on the suspect PS and can see voltage pulsing so PS is the weak link...

Interesting review of product data claims 2x 10W led strips powered from 5V @ 2A ps... that does not compute...

I can easily find >2A 5V PS but that does not appear to be the immediate failure cause since lamps were not running at full brightness.

I found a couple 4.8A USB PS, but they appear to have 2x2.4A supplies driving dual output jacks.

These all apparently use the same chip set inside with automatic detection for over charging phone batteries. I would not be surprised if that auto detect is somehow misbehaving in the cold.

===

The PS starts working again after it warms up so next experiment is to put it inside the heated greenhouse, using an extension cord to see if that works. This is kind of nuts, but we'll see, if it hangs overnight at 50'.

JR

Re: home improvement turns into science fair projects?

Posted: Sun Nov 10, 2019 11:21 am
by mediatechnology
But you go for it...
I never said I wanted to compete in that space.
You assumed that. It's like a knee-jerk reaction or something.
Squirrels giving you trouble JR?

All I said is that I would buy USB to Universal barrel connector wall-wart replacements if I could find them to eliminate the "wart" in wall-wart.

terkio - I have one of those vintage mercury-based Honeywells in storage. They are very clever particularly the anticipator gizmo or whatever it was called which self-heated the bimetal coil IIRC.

Re: home improvement turns into science fair projects?

Posted: Sun Nov 10, 2019 12:32 pm
by JR.
mediatechnology wrote: Sun Nov 10, 2019 11:21 am
But you go for it...
I never said I wanted to compete in that space.
You assumed that. It's like a knee-jerk reaction or something.
I already explained that my "small market" comment was regarding technically literate.
Squirrels giving you trouble JR?
New products that don't work reliably, are somewhat irritating. :x

Actually the squirrels appear to be camera shy... since I installed my squirrel cameras they have been pretty much absent. A good thing, IMO.

JR
All I said is that I would buy USB to Universal barrel connector wall-wart replacements if I could find them to eliminate the "wart" in wall-wart.

terkio - I have one of those vintage mercury-based Honeywells in storage. They are very clever particularly the anticipator gizmo or whatever it was called which self-heated the bimetal coil IIRC.

Re: home improvement turns into science fair projects?

Posted: Mon Nov 11, 2019 8:03 am
by JR.
The USB 5V supply survived overnight inside the heated greenhouse. Overnight lows outside were only in the 40s so we'll get a real test over the next few days, where 20s are forecast.

I am still curious about whether this is a personal problem (fault in the individual PS), or a design flaw related to temperature sensitivity of smart battery charging circuitry.

JR

Re: home improvement turns into science fair projects?

Posted: Tue Nov 12, 2019 9:51 am
by JR.
One 60W bulb was not enough to keep the UBS supply happy, more like a 3 dog night (30s). :lol:

I happened to still have a 3 lamp fixture mounted under my computer desk as a leg warmer from back before I got my 2 ton heat pump. That 3x 60W fixture almost immediately warmed up the green house and PS enough to work again.

I have ordered a replacement USB PS so more experiments to follow.

JR

Re: home improvement turns into science fair projects?

Posted: Tue Nov 12, 2019 4:45 pm
by mediatechnology
What is the wattage of the USB supply?

Re: home improvement turns into science fair projects?

Posted: Tue Nov 12, 2019 5:46 pm
by JR.
mediatechnology wrote: Tue Nov 12, 2019 4:45 pm What is the wattage of the USB supply?
It is nominally 5V @ 2A, despite powering two nominally 10W grow light strips.

I found versions of these rated from as little as 1A and 2.4A. I suspect it's all the same chip... Higher current versions like 4.8A typically have dual USB connectors so 2.4A per connector.

The PS quit again, despite being inside the warmed greenhouse. :oops: The controller dongle was still outside.

The 3x60W bulb heater is warmer but lows in the 20s forecast tonight will be a good test. I put a hi/lo thermometer inside the green house so I'll see tomorrow if the heat can keep it above freezing.

This USB PS seems puny (or funny).

JR