Intermittent runtime measurements?

Max

Enlightened
Joined
Dec 31, 2001
Messages
258
Location
Teaneck, NJ
Here's an idea I thought I might toss out to those of you who are performing flashlight runtime plots.

The standard disclaimer on any time vs. light plot is always that the graph shows what happens during continuous use, and that performance under intermittent use will differ.

I would be curious to see what it would look like to see a plot of intermittently used flashlight.

For example, let's say that you wired up the flashlight in such a way that a relay was inserted into the battery path that could be turned on and off by computer. One run would consist of turning on the flashlight and recording the light output for say 2 minutes. Then you would turn off the light and let the batteries recover for a bit and then repeat.

At the end of the run, you would have hundreds, if not thousands of these 2 minute segments. If you take every 10th (or 100th, depending on what kind of battery time we're talking) plot and overlay them on top of each other, you get a sense of how the performance changes as the batteries are depleted.

What might you see? Some of those unregulated lights might start to look flatter when you always start with rested batteries. Likewise, some of those really long runtimes might start to look overly optimistic when you consider that rested batteries are going to crank more current initially.

Anybody tried this?
 

Roy

Farewell our Curmudgeon Administrator
Joined
Apr 14, 2002
Messages
4,465
Location
Granbury, Tx USA
I realize that doing a runtime plot on a 100% duty cycle is not very realalistic. But what duty cycle should I use? That thread would go on for weeks!
smile.gif
Is someone willing to build an adjustable black box that is able to switch 10-20 watts of power? And how would it be hooked up to any given flashlight? A 20% duty cycle is two minutes on and eight minutes off. I terminated the LW 4000 plot at 5 DAYS because it was hogging the computer. On a 20% duty cycle the LW 4000 would take weeks! Ever try and keeps Windows up for weeks? This is the second time for this reply as Windows crashed when I hit the "Add Reply" the first time I wrote this! I have other programs that are running 24/7 and it seems that too many running 24/7 makes Windows very prone to crashing.
 

KC2IXE

Flashaholic*
Joined
Apr 21, 2001
Messages
2,237
Location
New York City
Originally posted by Roy:
...snip... Ever try and keeps Windows up for weeks? ...snip...
<font size="2" face="Verdana, Arial">Do it all the time! Before my little one started toddling around, I was up close to 300 days on this box, and usually go over a month with my PC at work - and at work, I'm HARD on my PC, as I'm a developer, and I could crash the box at will if I'm not careful (there are API calls that are documented to bring the box down if you pass certain values)

Right now, this box is at about 3 hours - Hugh pulled the keyboard plug out of the back!
 

Saaby

Flashaholic
Joined
Jun 17, 2002
Messages
7,447
Location
Utah
Roy Roy Roy....it's all about Windows 2000. My computer has forgotten what "Shut Down" is....it is verry good about standing by though
 

Max

Enlightened
Joined
Dec 31, 2001
Messages
258
Location
Teaneck, NJ
Originally posted by Roy:
But what duty cycle should I use? That thread would go on for weeks!
smile.gif


Good question. I don't know. I picked 2 minutes of on time as a reasonable amount of time that a person might use a flashlight continuously for an average task. How much recovery time do batteries need after that? I don't know.

Is someone willing to build an adjustable black box that is able to switch 10-20 watts of power?

Something like this: COMPUTER RELAY BOARD KIT

And how would it be hooked up to any given flashlight?

You'd probably have to run the flashlight open with the batteries and relay externally, with wires going to the connectors of the flashlight head. Yeah, I know that could interfere with heat sinking for some lights.

On a 20% duty cycle the LW 4000 would take weeks!

Okay, but how about an ARC AAA?
 

Max

Enlightened
Joined
Dec 31, 2001
Messages
258
Location
Teaneck, NJ
Hah! Here's the solution:

Get a bank of computer-controlled relays, and then hook up like five flashlights pointed at the same photocell.

Set your computer running recording 2 minute segments for each flashlight in rotation. That way you've got the computer recording voltages 100% of the time, while each flashlight is only on 20% duty cycle.

Man, I'd love to see a photo of that setup!
 

MrAl

Flashlight Enthusiast
Joined
Sep 9, 2001
Messages
3,144
Location
New Jersey
Hello,

Actually, that wouldnt be hard to build.
Probably use a 555 timer ic and a relay.

If you want to build one, let me know.
Have you ever built up electronic circuits?

Take care,
Al
 
Top