Nature discuss 4 June 2018
Make a free light from roof or window
It really a good idea to use sunlight as bulb light. It free and environment friendly.

If you use it on roof. Make it with a bottle. Add water and a bit bleach. Bleach can prevent algae grow in bottle. It specially decide for metal root. But it can also use with brick roof.

For the window, you can simply make a hole. Allow light access to indoor. You may also try to make a hole on metal piece or card board. To control enough light get indoor. And resist excess light and heat from outdoor. You will get a comfort place for reading and writing...

Nature discuss 5 June 2018
Today is World environment day
This year target

Nature discuss 8 June 2018
Make a 4 usd cooler

solar power motor
battery case (old toy or hobby)
fan leaf
big metal piece
2AA rechargable battery
Add ice at back to make cold air

Nature discuss 8 June 2018
Louver Fan and Diy Cooler make room cooler in rainy day
It keep room 25.5 degree c in 6 hours

Below it possible the calculation

Nature Discuss 10 Jun 2018
Air conditoner and Diy cooler drop 1 degree c in a night
Air conditioner set to be 22 degree c and closed the diy cooler when at night.

The next day morning. Check the temperature drop 1 degree to 21 degree. while out door temperature at 29 degree c

Nature Discuss 11 Jun 2018
Undersea cleaning robot

Nature Discuss 12 June 2018
How to make undersea robot - technical issue

Nature Discuss 14 Jun 2018
How to use Remote control

Nature Discuss 14 Jun 2018
How to connect battery and Rc motor

Nature Discuss 15 Jun 2018
Diy cooler with cold drink

Nature discuss 17 Jun 2018
7.2 fan add protective cover

Nature Discuss 20 Jun 2018
7.2 v fan test on diy cooler

Nature discuss 22 Jun 2018
Light up led with 7.2 v battery
It have to use with at most 1000 ohms resistor, It approximate 1A electric flow in the circuit.

You should test from lower ohms. Then more and more.

You should also know the Led max volt and electric flow limit before testing.

Too high electric flow would destroy the led bulb.

Each led need 2.4v and there are 3 , so it need 7.2v to light up

Nature discuss 28 June 2018
Best of June