LPC-815 / rkcstr Question?

[Keylitho]

I am using a LPC-815 diode with a rkcstr V3 driver powered by a 3.7 1000ma lithium rechargable battery.

I cant get the rkcstr driver to output more than about 250-300ma to the diode with that battery. (same results with a 2500ma battery as well)

I know it can handle up to 12v but when I double the voltage and set the thing to 400ma the driver starts getting quite hot fairley quickley.

So I have settled on the settings I could obtain with one battery, But I still keep thinking that I am doing something wrong.

Thanks..

~Erik

 

[bryce007]

the rckstr driver needs around 2.5V over diode voltage. So the LPC's forward voltage is 3-3.5v, so you want at least 6v. Two 3.6V rechargeables work great for the LPC with rkcstr. The driver gets hot because any extra voltage gets converted to heat, unlike buck drivers which convert the extra voltage to current. It is going to get hot, but it can handle it, just don't run it for long periods of time if it's in a handheld laser

 

[Keylitho]

Well I ran it for about 30 sec and It was very hot to the touch! It that too hot?

And what do you call long periods of time?

 

[bryce007]

Well I ran it for about 30 sec and It was very hot to the touch! It that too hot?

And what do you call long periods of time?

Well I don't run mine for over 1 minute at a time. I could run mine longer, since the driver is isolated from the diode, but I still stick with 1 minute duty cycle to be safe.

 

[JTBA]

Im using that same build basically, except i am trying to run it on 4 aa (recharge) and i am barely getting any light at all, even with the pot turned up high.

 

[bloompyle]

This thread is nearly 4 years old.

Please do not necro-post.

Minimum to get anything really is 6V. Chances are your 4x AA's batteries are about 1.45V each, not perfect 1.5V. So you aren't even hitting 6V.

Use 2x li-ion recharge-able batteries to get 8.4V instead.