SSC P7 x2 @ 2.8A each?

[jontawn]

Dear CPF,

Just toying around with the idea of running 2x P7's in my bike light, heat-sinking should not be a problem as i think I have this one sorted, if you could help, would it be more appropriate to use 2x of these per LED? http://www.kaidomain.com/ProductDetails.aspx?ProductId=1866

Or, as my electronics maths escapes me (i'm on my 9th day of 12-ish hour days) Would it be more appropriate to connect the LED's in series?

Apologies if this is a dumbass question!

cheers,
Jonathan

 

[steve6690]

It's not a dumb question. FWIW I'd rather use one of these :

http://www.led-tech.de/en/LED-Contr...wer-Supply--2800mA,-30V--LT-1291_118_119.html

and connect the led's in series

 

[1 what]

You might also consider this (from mySmartTrolley.com.au) for your batteries :devil:.

 

[jontawn]

Steve6690; Funny that ... I've got one sat on my desk at home so that'll do nicely thank you

Cheers for your help!

JT

 

[steve6690]

No probs. I emailed Led-tech and asked if that driver would handle 3 x P7's in series and they stated that it would do so.

 

[jontawn]

While on this note, i'm looking at using some 18650's (3.7v & 2500mah (from dealextreme))... Which leads me onto thinking I need to connect these in parallel (4x of them in total) to give me a fairly lengthy runtime.

Does this board keep the voltage as well as the mA? ... or is that not needed?

Confused,
Jonathan

 

[Packhorse]

Dear CPF,

Just toying around with the idea of running 2x P7's in my bike light, heat-sinking should not be a problem as i think I have this one sorted, if you could help, would it be more appropriate to use 2x of these per LED? http://www.kaidomain.com/ProductDetails.aspx?ProductId=1866

Or, as my electronics maths escapes me (i'm on my 9th day of 12-ish hour days) Would it be more appropriate to connect the LED's in series?

Apologies if this is a dumbass question!

cheers,
Jonathan

I tried it running off a 12v battery and found the driver got really hot. This may have been more due to the higher input voltage that because it was running 2 P7s in series. In fact it soon went into thermal protection. I then made up a small heat sink and thermal glued the driver to it. Seemed to work really well. I did notice thatthe current dropped to 2.6 amps with 2 P7's though.
What I may try with my next project is run 6 Q5's off of the same driver by paralleling 2 lots of 3 in series. this should give them about 900ma each.