31   General / General Videos / Interesting phone with fluorescent backlight  on: November 19, 2024, 11:10:02 AM 
Started by LightsAreBright27 - Last post by LightsAreBright27
This video I found shows a Nokia phone which used a small ccfl backlight for its main display. As far as I know, this is the only phone model to have it, as successors used led backlights. I recommend skipping to 4:00 in the video to see the backlight driver, and 4:20 for the tube itself.https://www.youtube.com/watch?v=RXlP2jOr56A
 32   General / Off-Topic / Re: Are inverter air conditioners can heat better at very cold temperatures?  on: November 19, 2024, 11:04:11 AM 
Started by dor123 - Last post by dor123
I thought that car air conditioners uses scroll compressors. And how the modern air conditioners are so quiet if they are using reciprocating compressors?
Video of a local made air conditioning unit from the 90's on heating.
Video of a modern Gree made air conditioning unit, on heating.
I doubt that the newer Gree one have reciprocating compressor, as it is much quieter than the older local made one.
 33   Lamps / Vintage & Antique / Re: 1000w H34 mercury vapor lamp/ballast system tripping 15a 120v circuits  on: November 19, 2024, 08:45:15 AM 
Started by WorldwideHIDCollectorUSA - Last post by funkybulb
Also Cedrick  u also have two 20 amp circuit  in the kitchen
That been National Electric code for a long time.  But only problem is lot times Ground fault inerupted   Been that way  since 1975 code.   I used to live in a older house before that date,  but also u could not upgrade it to GFI.  Because they never made them for Aluminium wiring.

  But it beast to study your breaker panel ( consumer unit) to see what  current breakers are how Accessable those outlet are
 In your house.   

    In my case my house is on 125 amp breaker but I have a 200 amp service out on the pole.   I have abilty to shut off my house breaker.  And have full access of 200 amp to another breaker panel that i can tinker with.  But I have one problem my power company  only me 25 KVA out on the pole.  If i wanted to do light up bunch of mercury vapor 12 KVA is max i wil put on utilty
 Transformer.  I also have special request that I do not want any other houses on my transformer.  So far most I put on it is 11 KW
 But most of that is resistive loads in the winter month.  About 5 KVA of reactive power in the summer months 
 34   General / Off-Topic / Re: Cats under special lights  on: November 19, 2024, 05:34:18 AM 
Started by Laurens - Last post by AngryHorse
Don’t have any pictures under certain lighting, but we’ve got our first flurry of snow here this morning, and our Duke is snuggled up in his winter cat blanket 😃, yours look absolutely adorable though 🥰
 35   General / Off-Topic / Re: Are inverter air conditioners can heat better at very cold temperatures?  on: November 19, 2024, 02:32:56 AM 
Started by dor123 - Last post by Medved
The scroll or vane compressors have one huge disadvantage: They lose efficiency very rapidly once the compression ratio departs from the operating point they are designed for. So they lose efficiency once the temperatures depart from the design optimum. This may become acceptable for air conditioning, but the wide temperature ranges related to high efficiency heat pumps would mean the efficiency would become poor (it always operates at the ratio dictated by the geometry, then just dropping the excess pressure by passing the gas via narrow constriction).
Reciprocating piston (with simple reed valves) can vary the compression ratio in virtually unlimited range, the passive valves are just controlled by the pressure, so the efficiency remains pretty constant over very wide range of compression ratios.
Yes, the losses are a bit higher compare to a scroll or vane type operating at design ratio, but once the pressure requirements are forced to depart from that optimum, the efficiency of the rotary drops very significantly while the reed valve piston remains quite constant.

But the compressor does not have to be rotary (vane or scroll) type in order to be silent, with reciprocating design it is just matter of balancing the thing out.
Frequent way is to use V-90deg two cylinder configutration, a simple counterweight on the motor shaft does balance the pistons near perfect, so the only vibration remains is the torsion one (because of the irregular loading along the rotor position angle). But with an inverter technology this is not that hard to suppress, you just design the synchronous motor so the peak torque from the motor itself matches the phase with the peak torque requirement of the 90deg V-twin compressor arrangement (when both are compressing). It leads even to rather simple single phase BLDC design, sufficing with just a simple 4-transistor bridge as the power stage of the inverter.

Other popular option is a star 3 cylinder configuration, this balances all forces naturally, include majority of the torque vibration (the load is spread evenly over the whole 360deg). But the drawback is more cylinders, so higher piston surface/volume ratio, so it goes mainly towards higher power systems. This then works even with basic induction motors.

By the way car air conditioning compressors are virtually all piston reciprocating type, usually about 5..9 cylinders or cylinder pairs (for double acting designs) and that makes them perfectly smooth.

Yes, multiple cylinders do not work that well for low power systems (like fridges or so; due to high surface-to-volume ratio related losses), but house HVAC uses to operate at power levels where these losses are not that bad.

Linear vibrating compressors are a technology many companies are experimenting with, because of simple linear motion it is rather easy to balance out any forces so they do not transfer any vibration to the case at all at the same time having just one cylinder so very good surface/volume ratio, but it is really in its infancy, far away from getting released "into the wild". So far LG tried it in home refrigerators and it was huge reliability failure.
 36   General / General Discussion / Experiences with using portable solar generators to run lighting off grid?  on: November 19, 2024, 02:13:22 AM 
Started by WorldwideHIDCollectorUSA - Last post by WorldwideHIDCollectorUSA
After I have been using a Jackery Explorer 290 solar generator with a pure sine wave inverter to power my 2024 Halloween costume that consists of using a 40W T9 circline fluorescent lamp as a necklace that runs off a single lamp F40T12 preheat fluorescent ballast along with using it to run a few low wattage HID lamps such as 100W H38 mercury vapor lamps, 75W H43 mercury vapor lamps, and 35W S76 high pressure sodium lamps; I am beginning to wonder if anybody else has ever tried using portable solar generators to power any of their lighting collection off grid before. If so, what are your experiences of running your lighting collection off grid using solar generators?

Here are some examples of solar generators currently on the market:

Anker C300X solar power station:

https://www.anker.com/products/a17221z1?variant=44204711280790

Jackery Explorer 300 Plus:

https://www.jackery.com/products/jackery-explorer-300-plus-portable-power-station?srsltid=AfmBOopliuIDtraOHG1hFoNKxH8ZclBesRt5PiaL-L2ZZuXzDedUf6JI
 37   Advertisements / For Sale or Trade / Re: Free to a good home : ex-Sylvania stocks  on: November 18, 2024, 08:56:21 PM 
Started by James - Last post by GE PM
Have any more been given away? How much is left
 38   Lanterns/Fixtures / Modern / Re: Will a rusted SON ballast work?  on: November 18, 2024, 02:45:20 PM 
Started by veso266 - Last post by Laurens
GP20na is low pressure, so it's yellow and stays yellow. There is some other starter gas in there, because it starts on mains voltage and does not need an igniter, but that has very little influence on the color rendering.

It is meant as a spectrum lamp, so the amount of light you get out if it is much less than from a SOX18, but enough to function to light up a dark corner of a room.

The lamps that glowobject sells are also sold by DBL i think.
 39   Lanterns/Fixtures / Modern / Re: Will a rusted SON ballast work?  on: November 18, 2024, 02:29:17 PM 
Started by veso266 - Last post by veso266
GP20Na also does yellow (does it also color change when it starts up?), would love to see a video of ur setup

Hmm never heard of them, nice

Although I prefer SOX due to color change when starting up, best thing is that they are still being made: http://www.glowobject.com/

Although not sure about quality

Will get SOX as soon as I found a nice fixture, thats not a streetlamp

Will try my 400W lamp on my 250W floodlight and hope it stays yellow
 40   Lanterns/Fixtures / Modern / Re: Will a rusted SON ballast work?  on: November 18, 2024, 12:21:39 PM 
Started by veso266 - Last post by dor123
When you underdrive a brand new HPS lamp, it would reach SOX color. Only used redded out HPS lamp, where the sodium-mercury ratio is more to the side of the mercury, will show the mercury lines when dimmed and won't reach SOX color?
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