A Perspective On The B Type EESD - Robert Murray-Smith - Any issues?

[tinman]

What is the challenge? Here's one:

1) 1.5V bench power source (not a battery)
2) 3 LED's (of agreed upon part number) in series.
3) The challenge: Light the 3 LED's with a circuit powered off the 1.5V supply. Correctly measure the input power (Pin from source) and output power (Pout power (total) dissipated by the 3 LED's). The highest Pout/Pin ratio wins.

Caveats:

a) The frequency of operation must be between 1kHz and 100kHz.
b) Total Pout (all 3 LEDs combined) must be 60mW minimum (greater than 60mW is fine).

My understanding is that itsu would offer his services as builder and tester for any circuit MH would come up with to go against Brad's circuit.

Sounds like fun


I have to ask though,why would it matter what LEDs we use,if we are measuring the power being delivered to them?.


Brad

[poynt99]

That all sounds fine and dandy except for the fact that if I wanted to do it I would need to work on a bench to iterate on a design.  Since I have no bench and no desire to do it, it's not going to happen.  I can't just put something on paper without testing it and iterating on it myself.

However, I admire the way you formulated the challenge, it makes great sense.  Something similar should be done for a pulse motor build-off to make it more interesting.  Or what you just stated is perfect for a Joule Thief build-off.

MileHigh

You could always simulate a design.

The design can be anything by the way; one of your own, something from an application note from Linear Technology, something COTS off ebay, you name it. Perhaps itsu has an idea of his own, and you two could collaborate on it?

[poynt99]

I have to ask though,why would it matter what LEDs we use,if we are measuring the power being delivered to them?.


Brad

To make it more fair, controlled, and comparable, the source and load should be the same. Different LEDs have different forward voltages etc., and using a different forward voltage might give an efficiency advantage.

[tinman]

However, I admire the way you formulated the challenge, it makes great sense.  Something similar should be done for a pulse motor build-off to make it more interesting.  Or what you just stated is perfect for a Joule Thief build-off.

MileHigh

That all sounds fine and dandy except for the fact that if I wanted to do it I would need to work on a bench to iterate on a design.  Since I have no bench and no desire to do it, it's not going to happen.  I can't just put something on paper without testing it and iterating on it myself.

MH

I have to say that i do understand what you have stated above,but at the same time,i am a little confused. Was it not you that stated that the pen was mightier than the bench?,but now you say you need the bench before you can put pen to paper

Anyway-Poynt
That challenge seems to good to let go to waste.
How about we make it a forum challenge?--where you join in as well
Going by your parameters of the challenge,we are looking for the most efficient boost converter to run 3 LED's-yes?.


Brad

[tinman]

To make it more fair, controlled, and comparable, the source and load should be the same. Different LEDs have different forward voltages etc., and using a different forward voltage might give an efficiency advantage.

Fair enough.
I only hope that i can get the LEDs you choose--maybe those big 10mm ones,although i have a heap of the 5mm ones from solar garden lights. ?

Brad