Recent content by RaGun

This is the important question for me. UV dose µWs/cm² = UV intensity µW/cm² x Exposure time (seconds) The LED site mentions the radiant output of 50mW but doesn't mention the area so I'm not sure what to put in the UV intensity section of the above equation. Would it be the internal area of...

Hey everyone, I recently came across UVC leds and was wondering if they could be used to disinfect water in a simple way. If I got a bucket with 5 litres of water in it, stuck a 50mW radiant flux UVC led (like this) on the lid and run it for 1 minute would that be enough time and power to...

Came across this interesting write-up saying that a bio reactor which exclusively ran on human solid waste wouldn't run due to the nitrogen content. http://large.stanford.edu/courses/2010/ph240/cook2/

Hello everyone, For villages in Africa and Asia that still use wood, dung or other biomass in simple stoves which option do you think will be better? Concentrate solar energy into an insulated unit with a molten salt which can then be used at any time or build a simple biogas generator (large...

I'm not understanding the maths. If you pedal continuously at a rate of 50 watts wouldn't it take nearly 50 minutes to generate the 40Wh (50/60=0.833W/minute then 40/0.833=48 minutes). The really important question is, will people actually do it? Even if you split it up so you do it 10...

I'm pretty sure that that is correct. The battery is pretty small, it says 12V 6Ah which is 72Wh but like I said you can't use all the capacity so I think the manufacturer recommended the 40Wh figure for long term use.

Our lamps use a lead acid battery with a usable capacity of 40wh, the actual capacity is higher but because it's not deep cycle the system cuts off at a certain % which I can't remember. I think that this number was decided so a family can use 20wh on one day and still have another 20wh left on...

Thank you for the replies, I actually wasn't expecting this many especially so soon. At first thermoelectrics seemed ideal but after doing more research it's seem like 95% of the energy would be wasted as heat because they only operate at around a 5% efficiency. Our country is hot enough as...

Hi, I volunteer for a small group who try and help the families who live in the rural parts of Sri-Lanka We have built and donated a large number of solar powered lanterns but during the rainy season (or even on cloudy days) we don't get enough sunshine for the lights to work for their...