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I book a flight for my fiance for $91. But on the wrong day.
I go to change it when we realize it. Its $181 to move the flight to the next day.
Google flights.....
I can book the flight that were moving it to...for $144.
It is literally cheaper to skip the cancellation fee ($125), just not show up, and buy a flight for the next day.
I book a flight for my fiance for $91. But on the wrong day.
I go to change it when we realize it. Its $181 to move the flight to the next day.
Google flights.....
I can book the flight that were moving it to...for $144.
It is literally cheaper to skip the cancellation fee ($125), just not show up, and buy a flight for the next day.
What airline? Sounds like United.
Oh wait, no, the change fee is too low for United.
What airline? Sounds like United.
Oh wait, no, the change fee is too low for United.
(This is one reason why I like flying Southwest)
yeah I tried that once. I booked a round trip flight and decided that I wanted to leave a day early. I booked a new one way ticket for around $150 to leave early, and they cancelled the second leg of my round trip ticket and said that since I didn't get on the first leg, they resold my seat for the second leg. A few hours of bitching, they finally rebooked me using some travel agency third party. They tried to get me to pay for a third $1400 same day ticket, and I was not having that.
I book a flight for my fiance for $91. But on the wrong day.
I go to change it when we realize it. Its $181 to move the flight to the next day.
Google flights.....
I can book the flight that were moving it to...for $144.
It is literally cheaper to skip the cancellation fee ($125), just not show up, and buy a flight for the next day.
Here's what I did once:
I showed up, and asked if the flight was overbooked. It was.
I simply told them there were too many unhappy people in the line behind me, and I could make at least one of them happy by giving up my seat.
They were more than happy to move me to a date of my choosing, and they gave me coupons for all kinds of free stuff.
That was that.
Here's what I did once:
I showed up, and asked if the flight was overbooked. It was.
I simply told them there were too many unhappy people in the line behind me, and I could make at least one of them happy by giving up my seat.
They were more than happy to move me to a date of my choosing, and they gave me coupons for all kinds of free stuff.
That was that.
BOO! Where's the fun in that? Why give coupons when they can punch someone in the face and drag them down the aisle!
I am a bit out of my depth and I need help please...
This is about the show.
We were wearing goggles while we were doing stuff that required eye protection.
They were awkward and made us sweat like pigs, so we kinda gave up on them after a while, and that was not cool.
So I thought why not use polycarbonate full face shields, right?
Put them by the grinder, metal cut off saw, wherever they are needed, and that would be it.
I had a talk with the director about that. He was hesitant because he thought the full face shield would make us look like robots and mask the facial expressions.
So, I had an idea.
Like every respectable movie astronaut who has his/her face lit from inside the helmet, I could light our faces from inside those face shields...
I decided to put together a prototype and make a presentation before I said anything else about it.
And promptly bought a shield...
And, I bought an LED dimmer with a fancy remote control.
I took the dimmer apart and used just the circuit to save space, stuck an LED strip inside the head piece and supplied power with a couple of 6 Volt MiMH batteries hooked up in series for the required 12 Volts necessary for the LEDs.
The battery packs are 1800 mAh each.
The idea was wearing the face shield and tossing the remote to the director as he was complaining about not being able to see the face.
His reaction was priceless when I did that.
The idea of remotely turning on and off and adjusting the light to suit the environment was a huge success.
BUT, I ran into a couple problems.
Batteries do not last long. I can maybe get 10 minutes out of them before the voltage drops down to where the LEDs do not come on.
The LED strip (18 LEDs total) consume 0.4 Amps. I checked that with my amp clamp.
The dimmer circuit seems to be consuming current, too, because batteries were dead after a few hours even though the LEDs were off.
Do you think I have bad batteries, or should I go to 18650 batteries, or even LiPo?
(A battery pack clipped on a belt, etc is not desirable, the director wants these things as compact and easy to use as possible)
There is also an idea for rotary dimmers on the side of these things (something about too many remotes to deal with while shooting the show)
My electronics knowledge is limited. Can I use a potentiometer to dim these things?
If so, what range/spec/ohm/whatever should they be?
Is there a specific type of LED I should use/avoid?
Can you suggest a compact battery solution for this setup?
These are 12 Volt LEDs. How high can I go safely with the battery voltage (for some headroom)?
I'll probably end up making like 10 of these, with replacements along the way as they get destroyed.
This is the only place I know to ask for help on these matters, hope you guys don't mind me rambling here.
Can you take a better picture of the dimmer/receiver? I don't think you can use a potentiometer as the dimmer is probably PWM controlled (LED's are current driven, not voltage). A single 18650 is going to be about ~2400mah, throw in a cheap ebay boost circuit and you can get it pretty small. Those appear to be basic 5050 LED's - you could get a lot fancier, depending on how much time you had to dedicate. Put on a 12v power supply directly on the LED's and measure, divide by 18 and you'll have your current draw.
Can you take a better picture of the dimmer/receiver? I don't think you can use a potentiometer as the dimmer is probably PWM controlled (LED's are current driven, not voltage). A single 18650 is going to be about ~2400mah, throw in a cheap ebay boost circuit and you can get it pretty small. Those appear to be basic 5050 LED's - you could get a lot fancier, depending on how much time you had to dedicate. Put on a 12v power supply directly on the LED's and measure, divide by 18 and you'll have your current draw.
Can you take a better picture of the dimmer/receiver? I don't think you can use a potentiometer as the dimmer is probably PWM controlled (LED's are current driven, not voltage). A single 18650 is going to be about ~2400mah, throw in a cheap ebay boost circuit and you can get it pretty small. Those appear to be basic 5050 LED's - you could get a lot fancier, depending on how much time you had to dedicate. Put on a 12v power supply directly on the LED's and measure, divide by 18 and you'll have your current draw.
Here's a close up, from two different angles:
(I can't take a pic of the other side, I hot glued it in place)
boost converter - takes a lower voltage, "boosts" it up - so you can take a 3.4v 18650 and turn it into 12v without adding batteries - fairly efficient. A buck converter does the opposite - 12v down.
Those 5050 (5.0mm by 5.0mm) LED's don't "need" 12v, they're designed for 12v inputs and probably have an internal resistor to drop it down to its forward voltage - which on something like a car / wall wart, doesn't really need it. Give me a second, and I can throw out an idea using ebay parts.
So the only part number I can make out is the 09N03 which is a 25v NPN mosfet. Guessing that's probably the PWM output, though I've used constant current LED drivers that usually have a PWM input for dimmer control - doesn't need the mosfet.
Do you think I have bad batteries, or should I go to 18650 batteries, or even LiPo?
(A battery pack clipped on a belt, etc is not desirable, the director wants these things as compact and easy to use as possible)
Even before I got down to this point, I was thinking "18650." You can get 3Ah at 4.2v in a package not much larger than a AA battery.
As for the beltpack thing, are your mics not clipped to the belt? My talent on the WGN news wear three separate beltpacks; two mics and one IFB. Doesn't seem to cause any problems.
I would advice you to reach out to JasonC. He specializes in power electronics. My expertise is small-signals stuff (eg: audio / video and high-speed data transmission) and I don't claim to know power electronics well.
You don't wanna use a potentiometer for this; too much power lost as heat. PWM drivers are available, though the only ones I'm familiar with are either DMX-based or expect a 120/240v supply.
And, is dimmable an actual requirement? Serious question. Since English subs aren't available, I haven't really watched a full episode, so I don't know what range of ambient lighting you have to deal with. But I'd think that for shields which are used only at a few specific workstations, you could tailor the number of LEDs per helmet to achieve approximately correct lighting at fully supply voltage with no adjustment. And, if you need to fine-tune, ask the gaffers (lighting technicians) for some filter gel. I have no idea how to translate that into Turkish. It's a thin sheet of transparent plastic which is placed in front of a light source to reduce the brightness and / or change the color temperature.
To touch on Dimmability and potentiometers - it won't work. The **** in the second ebay listing above probably drives a pwm generator that causes the LED to flicker really fast. Joe's idea of a gel might be good, as those LED's might flicker on camera if they are dimmed. And they can be surprisingly bright.
PWM dimming for LEDs can work, if the base frequency is high enough.
My new Studio 2 at WGN is 100% LED-lit, and it looks infinitely better on-camera than the old Halogen-lit Studio 3 did, particularly in shots in which a 60Hz monitor was also visible in the shot.
I have utterly no idea what the PWM frequency on the new lights is. It's beyond my ability to measure, but I can tell you that these instruments were ******* expensive. (My lighting bugdet for the new studio was a tad under $400,000, though to be fair, that also included the controller and labor.)
But gels are cheap, simple, idiot-proof, and basically guaranteed to work. And in terms of efficiency / battery-life, running the lights at 100% (having properly sorted out the voltage-current curve) will always beat any dimmer-based solution.
05-29-2017, 07:15 PM
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