Silviron
Flashlight Enthusiast
If you have been following my battery life tests closely, you may have noticed that I have had some trouble with accurate current measurements in the lower ranges....
Well, Friday when I went into Radio Shack to get a new soldering iron tip, I noticed that their #22-805 multi-meter was on sale for $49.95. Since I have been wanting one for several weks now, I figured that this was a serendipitous occurence and pulled out the checkbook.
So far, I am pleased with this thing. It is a lot more accurate than the DMM and the 2 analog meters I have been using. The specifications say that it is accurate to 1% - 1.5% in the ranges that we are dealing with in our LED light projects. plus, they will measure to 1/1000ths (3 3/4 digits as they call it, although it sure looks more like 4 1/8ths digits to me!
)
But the really neat thing is that it comes with a cable and software that you can plug into a PC serial port- You can hook it up to your "project", plug it into your computer, and get measurements of your volts, amps etc. at regular intervals and record them to a file that can even be directly inserted into a spread sheet etc.
The software even has a program that does a rudimentary oscilliscope simulation and can graph and record your measurements at intervals you can set- from one per second to one per hour or more.....
I haven't used this feature in a "real" test yet, but did two experimental ones on a "9V" (7.2V really) NiCd hooked up to 2 nichias, and was able to get a plot of the voltage curve over 6 hours and of current draw over 6 hours (on another charge).
It seemed to work well, and sure would be easier than staying up for days at a time
to do regular interval measurements. I'm sure that I am not the only one here that wants that kind of data...
The meters should be in your local Radio Shack (assuming you HAVE a local Radio Shack
If not, they are availible online at the sale price too.
Well, Friday when I went into Radio Shack to get a new soldering iron tip, I noticed that their #22-805 multi-meter was on sale for $49.95. Since I have been wanting one for several weks now, I figured that this was a serendipitous occurence and pulled out the checkbook.
So far, I am pleased with this thing. It is a lot more accurate than the DMM and the 2 analog meters I have been using. The specifications say that it is accurate to 1% - 1.5% in the ranges that we are dealing with in our LED light projects. plus, they will measure to 1/1000ths (3 3/4 digits as they call it, although it sure looks more like 4 1/8ths digits to me!
But the really neat thing is that it comes with a cable and software that you can plug into a PC serial port- You can hook it up to your "project", plug it into your computer, and get measurements of your volts, amps etc. at regular intervals and record them to a file that can even be directly inserted into a spread sheet etc.
The software even has a program that does a rudimentary oscilliscope simulation and can graph and record your measurements at intervals you can set- from one per second to one per hour or more.....
I haven't used this feature in a "real" test yet, but did two experimental ones on a "9V" (7.2V really) NiCd hooked up to 2 nichias, and was able to get a plot of the voltage curve over 6 hours and of current draw over 6 hours (on another charge).
It seemed to work well, and sure would be easier than staying up for days at a time
The meters should be in your local Radio Shack (assuming you HAVE a local Radio Shack
