beverly hillbilly storm windows and cybernetic heat control

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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Re: beverly hillbilly storm windows and cybernetic heat control

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mediatechnology wrote: Sun Jan 31, 2021 4:19 pm I used to sleep under an electric blanket as a kid.
The mechanical thermostat contacts were not snubbed.
Every time it clicked on or off I'd see a flash even with my eyes closed.
Those are my memories of an electric blanket.
yup my old one had a mechanical thermostat that clicked. The new one with a micro didn't click and it didn't work right either. :lol:

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Re: beverly hillbilly storm windows and cybernetic heat control

Post by mediatechnology »

terkio wrote: Sun Jan 31, 2021 6:20 pm
JR. wrote: Sun Jan 31, 2021 1:56 pm
I have some spare GFCI outlets in my stash, so the outlet by my bed now looks like a good candidate for GFCI.

JR
I searched to know what a GFCI is. I found a lengthy description that keeps repeating it protects from faults but nothing really clear ( or I was not patient enough ).
In France we have "differential breakers 30mA"
It monitors currents comparing phase current and return current. If current difference is more than 30mA, it trips, opening both phase and return.
A difference means there is a leak to ground, that could be through somebody :o .
This is mandatory to protect all circuits in kitchens and bathrooms. It is not at outlets, it is at the house main electric board.

How the GFCI works ?
That's exactly how a Ground Fault Circuit Interrupter works. They typically use a small current transformer with two windings that looks for a difference in currents. IIRC they are supposed to trip at 1 mA.
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Re: beverly hillbilly storm windows and cybernetic heat control

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mediatechnology wrote: Mon Feb 01, 2021 4:44 am
terkio wrote: Sun Jan 31, 2021 6:20 pm
JR. wrote: Sun Jan 31, 2021 1:56 pm
I have some spare GFCI outlets in my stash, so the outlet by my bed now looks like a good candidate for GFCI.

JR
I searched to know what a GFCI is. I found a lengthy description that keeps repeating it protects from faults but nothing really clear ( or I was not patient enough ).
In France we have "differential breakers 30mA"
It monitors currents comparing phase current and return current. If current difference is more than 30mA, it trips, opening both phase and return.
A difference means there is a leak to ground, that could be through somebody :o .
This is mandatory to protect all circuits in kitchens and bathrooms. It is not at outlets, it is at the house main electric board.

How the GFCI works ?
That's exactly how a Ground Fault Circuit Interrupter works. They typically use a small current transformer with two windings that looks for a difference in currents. IIRC they are supposed to trip at 1 mA.
I thought I already discussed this but don't see it now.

The spec for tripping US GFCI is more like 5-6 mA imbalance between current leaving line (hot) and returning to neutral. These are intended for use on individual outlets. 6 mA is lower than the current that causes muscle contraction where people get stuck on mains power. The European RCD breakers are designed to protect branch circuits with multiple outlets. The elevated trigger current (20-30mA) is to reduce false triggers that can be annoying to homeowners. 20-30mA shocks can be pretty annoying to humans, but is generally non lethal. Reportedly old wiring and dampness can cause mA of leakage in old buildings.

====
back on (my) topic, I used my red neck manual electric blanket last night but mainly to preheat the bed before I retired for the night, then I turned it down/off. All good...

I have seen used sunbeam controllers for sale on the internets but no need, I can live with KISS.

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Re: beverly hillbilly storm windows and cybernetic heat control

Post by JR. »

Yup I spent too much time messing with that stuff but while at Peavey one of our customer's got killed by a mis-wired outlet, so I am sensitive to the risk.

===

For some unexpected serendipity my subconscious engineering applications team figured out how to best implement my red neck electric blanket.

I already use my smart TOD thermostat in my bedroom with it's proportionate 5 PWM output levels to vary my air blower flow as needed, based on heat needs. Coincidentally I already have a drop where I can plug my blanket into the modulated mains voltage output near the foot of my bed. For now I still have it going through dimmer in case I need to turn it down, but I suspect I can probably plug it in directly. The existing TOD thermostat will work harder when first heating up the room at night, which will nicely warm up my bed at the same time. On warm nights the blanket will be just barely on, like the baseboard heaters. When the room is cold, more blanket heat should be appreciated.

The weather forecast predicts some overnight freezes coming this week so a fair test.

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Re: beverly hillbilly storm windows and cybernetic heat control

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The overnight freezing low gave my redneck electric blanket a fair test. Full on with dimmer was warmer than needed, despite room temp barely keeping up. I need to move the dimmer where I can reach it while under covers in bed so I can fine tune for comfort.

JR

[update- I rigged up a GFCI outlet for the hillbilly electric blanket... I had to add an extension cord to get the dimmer control over by my bedside table. I predict I will be able to realize a fixed set it and forget it dimmer setting, as this should track with room temperature very well. /update]

[update2- another proper test with overnight low of 28'. The low output (only 250W) baseboard heater was barely keeping room temp up to thermostat setting, but my red neck electric blanket needed to be turned down because bed was too warm. Right now the dimmer is set around 1/3 and bed was borderline too warm. A couple watts of electric blanket heat will be even cheaper than hundreds of watts of baseboard heat. :-)

I wonder if I could impute the temperature of the blanket heat element from its resistance (current draw). In theory that should work, but I don't expect it to make easily measurable changes over just a several degree range. Nah not worth the effort. /update]

[update3 some electric blankets use carbon fiber for heat elements, I can feel the wires in mine. /update]
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Re: beverly hillbilly storm windows and cybernetic heat control

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I made another tweak to my red neck electric blanket implementation. I moved the blanket under the mattress pad so it is warming me from below, this makes it easier to moderate body comfort by adjusting the upper blankets. I haven't touched the dimmer setting for a few days now so that looks dialed in (about 1/3rd up)...

The now warm bed is very comfortable and the colder the night, the warmer the blanket. On cold mornings I don't want to get out of bed..... sweet.

I could probably go lower than 250W baseboard heat but that is the minimum draw to keep that programmable thermostat happy.

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Re: beverly hillbilly storm windows and cybernetic heat control

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Got my latest electric bill...

==============

You used 15% less electricity than efficient homes.


You 1,303 kWh

Efficient Homes 1,536 kWh

Similar Homes 2,561 kWh

Dec 20, 2020 - Jan 21, 2021
This is based on 90 similar homes an average of 1 mile(s) from you. Efficient homes are the most efficient 20% of this group.


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