Help! What is causing this issue! Flexdrive set up at 1450ma...Tail current is 770mA?

[xXDUNNXx]

So I built another 445nm in an e2 host...the circuit goes like so

V+, flexdrive @ 1450mA, LD+

V+, Tact Switch, MOSFET Gate

LD-, MOSFET Drain, Case

MOSFET Source, Case

MOSFET Gate, 10K resistor, MOSFET Source

NOTE that Flexdrive is set at 1450mA and the resistance while on of the MOSFET is .20!

When reading current at tail cap...I get 770mA.

This translates into ~700mW when I planned on ~1.3W

What is going on?!?!?!?

Could it be the protected AW battery limiting the current?

I've seen builds with the same one battery-Flexdrive set up before pushing 1.5W. Would an unprotected LiMn do the trick?

Thanks in advance!

 

[DTR]

Reading from the tailcap won't give you the current the driver is giving to the diode with a flexdrive. That method would work with linear driver. But it should be drawing more like 2A+ from the battery @ 1.5A. Did you set up the driver on a test load? What is the flexdrive sinked to? 1.5A will require heatsinking to the host body.

Also you can't really say a specific current will translate to a specific output mW as there is a lot of swing in a 445 diode.:beer:

 

[xXDUNNXx]

Well...at 3.7V more like 3A with 80% efficiency. I was not thinking correctly about the driver when I posted that. Flaminpyro set it so I assume yes on the test load lol...I trust him. And yes, he cut me a custom hs for between the driver and aixiz which is pressed into the host. The m140 when fed right usually seems to translate pretty closley with the current into output.

Any ideas?

 

[xXDUNNXx]

Anyone?

 

[xXDUNNXx]

Would added resistance to the case cause this? I ask because the mosfet does add some resistance. Also, IMR's are on the way...

 

[Fiddy]

I suggest you do what dtr said - "set up the driver on a test load"

 

[xXDUNNXx]

Figured it out...I knocked off the pot setting luckily I marked it so I set it right back to where it was