A question about TnC Products

[Doug S]

I have a question about the TnC Products single cell lights (N, AA, AAA). I gather from various posts that these use the MJ Microconverter board design. Various posts have thrown around the figure of 200 mA for the typical drive current in these single cell lights. It is inherent in the design of the MJ microconverter that drive current will vary with cell voltage and LED Vf. Has anyone actually done any testing of the circuit used in the single cell TNC lights? If so, at what input voltage does the drive current reach 200 mA for a typical Vf Luxeon? Any additional data would be welcome if you have it such as drive current vs input voltage and efficiency values. TIA.

 

[javafool]

I just measured the 'N' cell that came in the mail today. At the battery end I measured 185mA and 1.3v. The 'N' cell light has more of a flood beam than the AA.

java

 

[Doug S]

[ QUOTE ]
javafool said:

I just measured the 'N' cell that came in the mail today. At the battery end I measured 185mA and 1.3v. The 'N' cell light has more of a flood beam than the AA.

java

[/ QUOTE ]
JF: I'm am really looking for the drive current to the emitter but your data is potentially useful to me also. Could you clarify a point or two? Was that 1.3V measured while the cell was under the load of the flashlight circuit? What amperage scale did you use for your current measurement? TIA.

 

[cy]

I have from good authority that ARC mania used RWOH in his mini-sammies. I'm not willing to risk destroying the emitter to verify the 200 milliamps at the emitter.

To my untrained eyes, Li14430 60/750 TWOJ on low is slighty brighter than TNC N-cell, both with fresh charge.

The only voltage I verified was li-ion cell is 4.15v fresh off charger.

I have to assume an H bin would be more effecient than a Jbin. Based upon output, ARC mania's board is less than 200 milliamps at the lux.

 

[Doug S]

The question that I made in this thread is probably better suited to the Electronics forum. Could a moderator move it please? Thanks.

 

[Doug S]

Bump

 

[javafool]

Doug S, The voltage and current were both measured from the negative end of the battery to the threads of the flashlight with the light turned on. I used the 0-400mA range on the Radio Shack DMM that was on special about a month ago.

Hope this helps.
java

 

[Doug S]

[ QUOTE ]
javafool said:

Doug S, The voltage and current were both measured from the negative end of the battery to the threads of the flashlight with the light turned on. I used the 0-400mA range on the Radio Shack DMM that was on special about a month ago.

Hope this helps.
java

[/ QUOTE ]

Java, Thanks. I understand on the current measurement but I am confused on the voltage measurement. I don't have one of these lights so I am confused about the geometry of the measurement. How did you access the positive end of the cell to take the voltage measurement while simultaneously making the current measurement at the negative end? Also, was the voltage taken at the + and - cell terminals or was the - connection measured on the flashlight body? The second method would show what the converter board is actually getting after the drop through the meter. If you happen to redo this measurement, could you do it on a higher ammeter scale?

 

[javafool]

I am totally confused about the voltage also. Don't send a mecahnical guy to measure electrical stuff /ubbthreads/images/graemlins/blush.gif

My DMM has two current ranges; 0-400mA and 0-10A. Sorry that is all I can provide now. Maybe I'll take it to work and bug one of my EE buddies with the challenge over lunch. We have equipment to measure about anything.

java