big amps? on a triple XP-L?

[seasam]

For those of you running triple XP-L’s… how does one break in to the big numbers such as 9+ amps?

I see about 7.3A tailcap on a triple XP-L V6, VTC5, 20ga wires, beryllium copper spring (no bypass) on a FET/DD board with SIR800DP FET.

The leads on the DMM are about 4-6” 18ga stuffed/wadded in to the connection ports.

For comparison I get about 4.25A on a XM-L2 U4, 22ga, qlite spring (no bypass), LD-2 with otherwise same testing setup.

Am I missing something? Are the variations due to DMM used and LED samples?

[hank]

more volts?

[Turby3Pots]

Likely, it’s still the DMM that is the problem. Put the light on a glass ashtray, Measure the amps, then touch the leads together while measuring amps (effectively cutting the DMM out of the loop) and you’ll probably find it gets brighter. This indicates the DMM was eating amps, in order to display amps.

I never saw more than 6 amps with a $20 craftsmen DMM, but it all but doubled in brightness with the RMM-test i just described above.

TL/DR: If you have a VCT5 and 3 XP-L’s in DD you are pulling all she can, regardless of what the meter says.

@hank

more volts?

hahah Hank

[seasam]

so maybe just my meter then. unfortunately it’s a cheap DMM, a klein. I don’t have the stomach for a fluke… even the 115-117 models. I know it can drop an amp in the reading if I don’t have a good connection on the leads to the meter. guess I don’t need to step up to 18a wires on my flashlight then… so that’s good.

[Turby3Pots]

well RMM told me that it really doesn’t matter which meter, $1k fluke or whatever, you still won’t see the number that it’s running at.

or maybe he didn’t say that, or said something similar.

but i learned not to sweat it, that it’s probably still hella bright

[DavidEF]

Clamp meter - doesn’t interrupt or use any of your current.

[seasam]

@DavidEF

Clamp meter - doesn’t interrupt or use any of your current.

oh yeah clamp meter. but those cost more money :weary:

@wdkingery

well RMM told me that it really doesn’t matter which meter, $1k fluke or whatever, you still won’t see the number that it’s running at.

or maybe he didn’t say that, or said something similar.

but i learned not to sweat it, that it’s probably still hella bright

lol yeah it’s still bright enough so I can’t really complain.

I think this is post 100. I guess that means I need to give something away? :party:

[Wrathbringer27]

@seasam

@DavidEF

Clamp meter - doesn’t interrupt or use any of your current.

oh yeah clamp meter. but those cost more money :weary:

@wdkingery

well RMM told me that it really doesn’t matter which meter, $1k fluke or whatever, you still won’t see the number that it’s running at.

or maybe he didn’t say that, or said something similar.

but i learned not to sweat it, that it’s probably still hella bright

lol yeah it’s still bright enough so I can’t really complain.

I think this is post 100. I guess that means I need to give something away? :party:

Thats up to you there isn’t any real rule to abide by for giveaways

[DavidEF]

@seasam

@DavidEF

Clamp meter - doesn’t interrupt or use any of your current.

oh yeah clamp meter. but those cost more money :weary:

@wdkingery

well RMM told me that it really doesn’t matter which meter, $1k fluke or whatever, you still won’t see the number that it’s running at.

or maybe he didn’t say that, or said something similar.

but i learned not to sweat it, that it’s probably still hella bright

lol yeah it’s still bright enough so I can’t really complain.

I think this is post 100. I guess that means I need to give something away? :party:

Clamp meters can be had for relatively cheap nowadays.

[texas_shooter]

I have two cheap Velleman dvm850bl meters that I use for a lot of quick checks. And like most cheap meters they don’t like high amp low voltage readings. I did wire both meters in parallel with one set of probes, each probe having 2 plug in wires When I’m in the 6+ amp range under 5 volts I often get a combined reading 10-20% higher than on a single meter. I also learned that one of the meters is also about 1/2% higher in readings than the other. I got these meters for about 12$ each at a Fry’s sale. So I’m betting with a great meter parallelled with a cheap one you’ll have a slightly higher combined reading.

[Werner]

Which battery are you using? And to which voltage is it charged? Try different batteries.

Also switch and spring resistance is making trouble with serious amps, there must always be a bypass even if you have good springs….you have to imagine that of there is 0.1 ohm resistance than its stealing 0.5V at 5A…and that prevents from getting big current…

[dchomak]

Try this to read the big amps.

How to read 10A, 15A, 20A and beyond with a cheap meter

How to read 10A, 15A, 20A and beyond with a cheap meter 08/15/2015 I added an addendum to the bottom of this post with detailed instructions on how to build the shunt resistor. And here is a link to my post #28 in this thread that I hope explains things more clearly . . Up until recently, I have never had to measure very high levels of current. Any measuring I have done were for single emitter lights that had current draws of no more than 5A. For that, I had used a DMM set to the 10A scal…

[seasam]

@texas shooter

I have two cheap Velleman dvm850bl meters that I use for a lot of quick checks. And like most cheap meters they don’t like high amp low voltage readings. I did wire both meters in parallel with one set of probes, each probe having 2 plug in wires When I’m in the 6+ amp range under 5 volts I often get a combined reading 10-20% higher than on a single meter. I also learned that one of the meters is also about 1/2% higher in readings than the other. I got these meters for about 12$ each at a Fry’s sale. So I’m betting with a great meter parallelled with a cheap one you’ll have a slightly higher combined reading.

intersting idea - I might give this a try if I get another meter, thanks.

@Werner

Which battery are you using? And to which voltage is it charged? Try different batteries.

Also switch and spring resistance is making trouble with serious amps, there must always be a bypass even if you have good springs….you have to imagine that of there is 0.1 ohm resistance than its stealing 0.5V at 5A…and that prevents from getting big current…

I’m using a Sony VTC5, but a Samsung 25R and LG HE2 give comparable results. I went ahead and switched from the copper beryllium spring (no bypass) with a brass top to a regular spring with a 22 gauge bypass tonight but I got the same if not slightly lower results.

@dchomak

Try this to read the big amps.

How to read 10A, 15A, 20A and beyond with a cheap meter

Now THIS I find very interesting. Looks like it’s arts and crafts time, but this is a very cool idea.

Thanks everyone!

[Keisari]

@DavidEF

Clamp meters can be had for relatively cheap nowadays.

Yeah, relatively.

If you're going to buy a budget clamp meter, check if it's AC only or also capable of DC clamp measurements. The former type has more complicated and expensive circuitry.

Don't be fooled. The cheap AC only clamp meters are marketed with vague claims of "measures AC and DC", meaning that they can measure DC current (or even just voltage) when using the leads. No mention of the clamp only sensing AC.

[seasam]

@Keisari

@DavidEF

Clamp meters can be had for relatively cheap nowadays.

Yeah, relatively.

If you’re going to buy a budget clamp meter, check if it’s AC only or also capable of DC clamp measurements. The former type has more complicated and expensive circuitry.

Don’t be fooled. The cheap AC only clamp meters are marketed with vague claims of “measures AC and DC”, meaning that they can measure DC current (or even just voltage) when using the leads. No mention of the clamp only sensing AC.

thanks for the tip. yeah I started noticing AC only on the cheap ones so I kind of gave up on this. maybe when I upgrade my tools I’ll look at this again.

[DavidEF]

@seasam

@Keisari

@DavidEF

Clamp meters can be had for relatively cheap nowadays.

Yeah, relatively.

If you’re going to buy a budget clamp meter, check if it’s AC only or also capable of DC clamp measurements. The former type has more complicated and expensive circuitry.

Don’t be fooled. The cheap AC only clamp meters are marketed with vague claims of “measures AC and DC”, meaning that they can measure DC current (or even just voltage) when using the leads. No mention of the clamp only sensing AC.

thanks for the tip. yeah I started noticing AC only on the cheap ones so I kind of gave up on this. maybe when I upgrade my tools I’ll look at this again.

OOOPS!!! Sorry, I hadn’t thought of this.