Minjun Kim

I think all great of acts are amalgams of a definite path and an unknown possibilities.

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TitleMidterm projects Kinetic & measuring "Energy memory box"2021-03-12 18:13
Writer Level 10


Project goal

For my midterm kinetic project I planned to make a box that has a knob that you could crank and charge a battery and discharge the capacitor to light up an LED once a day.

And then I will figure out how long do I need to crank the knob to charge the box fully and then how much calorie I will be burning.

I got to a point it will blink twice a day for 5 seconds but Instead of charging a capacitor I charged a battery instead.

I also built a solar BEAM pummer circuit but it doesn't work...


So first I tried my best to figure out how to charge a capacitor fast and discharge it slowly or maybe figure out how to separate the discharging process throughout the day but I learned that capacitors are more like a charging fast and discharging fast so I figured that Batteries is better alternative for my project. So I have got a rechargeable 9v battery from Amazon.
PICTURE OF RECHARGEABLE 9V BATTERY and Hand crank generator 
What I learned 
I had to figure out how to blink an led without using an arduino because I wanted to make this project analog as possible so I went to a thrift store to get a quartz alarm clock and opened it up.
I looked really simple,
what it looks like in the quartz alarm clock.
first I thought the tiny metal bar was a capacitor and after I did a research I learned its a tiny crystal oscillator!!
How the crystal oscillator works is its like a tuning fork that works when a small voltage goes in and create an electrical signal with a constant frequency and the term for that is piezoelectricity and the tuning fork vibrates 32,768HZ and that about 300000 times in a second.
What now?
Now I needed to figure out how to discharge the battery twice a day so I looked through some relay switches especially time delay switches and I bought this programmable time delay switch.
Photo of the programmable time delay switch
Now Lets wire it up!
Completed project in a box
I had to set the timer for seconds instead of minuites for the documetation 
As you can see after 72 seconds the switch turns on and it powers up the quartz circuit and blinks the led every 1 seconds so it blinks about 5 times in 10 seconds while the timer is on.
How I would like to improve this project
I will try to build my own time delay switch with 555 chip and learn more about time and capacitors it was really fun working with capacitors and generating electricity with a motor
Now Measuring!
Now I need to measure how long I need to crank up in order to charge the battery.
Here is the calculation that I have done.
Since I am using Battery type : 650 mAh NiMH size 9 volt rechargeable battery
It Require  : 4 1/2 hour(s) of re-charging in 200 mA current output charger
And that will be Fraction to : 4 1/2 hour(s) of re-charging in 200 mA current output charger
Now I need to figure out how much enery that I will be burning / spending or using to charge the battery
Since (Metabolic equivalent of task × 3.5 × your weight in kg) / 200 = Total calories burned per minute.
And I weight around 65kg
3 to 6 is  MET is Moderate intensity physical activites I will caluate (5 x 3.5 x 65) / 200
and then times 270 because there is 270 Minuites in 4 1/2 hours
and then it will come to conclusion that I will be burning around 1536 calories total
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