Hi,
I've been trying to soak up all the material on this forum, and reading from Martin's site with all it's excellent circuits for dynamo lights. I'd like to try building a fairly simple dual Cree headlight, but with hopefully with a standlight.
I haven't looked at circuit diagrams since I was a kid building crystal radios, so please forgive me if my questions are too obvious. Reading the forum messages, it sounds like you need to add a supercap in parallel to one of the led's for the standlight to work. But I've also read that you need to put a resistor in there as well, and on another site there was a diagram with a zener diode as a shunt to protect the goldcap from too much voltage.
What is the simplest way to get this working? Is it as simple as this?
Or does there need to be more between the Goldcap and the LED? What are the drawbacks to this design? I'd like to get a minute or two of light from the standlight when stopped and I would usually ride this bike at around 10mph for commuting. I'm planning on driving this first light from a bottle dynamo if that makes a difference.
Thanks!
I've been trying to soak up all the material on this forum, and reading from Martin's site with all it's excellent circuits for dynamo lights. I'd like to try building a fairly simple dual Cree headlight, but with hopefully with a standlight.
I haven't looked at circuit diagrams since I was a kid building crystal radios, so please forgive me if my questions are too obvious. Reading the forum messages, it sounds like you need to add a supercap in parallel to one of the led's for the standlight to work. But I've also read that you need to put a resistor in there as well, and on another site there was a diagram with a zener diode as a shunt to protect the goldcap from too much voltage.
What is the simplest way to get this working? Is it as simple as this?
Or does there need to be more between the Goldcap and the LED? What are the drawbacks to this design? I'd like to get a minute or two of light from the standlight when stopped and I would usually ride this bike at around 10mph for commuting. I'm planning on driving this first light from a bottle dynamo if that makes a difference.
Thanks!
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