Recharging Calcultors from Key press...Saving power

Replies

• 

  Anil Jain

  Do not know how much feasiable it is!! However looks like an interesting idea.
  
  -CB
• 

  silenthorde

  Hi CB
  
  Happy Birthday......
  
  Peizo crystals are expensive. Lets start with a basic calculator...contains about 20 to 25 keys. Each peizocrystal will produce a few millivolts per keypress.
  
  The charge will decay exponentially, because the Force applied on the keys can be approximated by a STEP function. So it needs processing circuitry.
  
  What do you say? Am I corerct?
  
  
  Regards
• 

  Ashraf HZ

  I guess we can complement this with the solar cell. They seem quite efficient 😀
  
  Keep in mind that to recharge the li-ion, the charge potential has to be higher than the battery rating. Assuming we are using the common CR2032 cell, you'll need something like 4.5V to charge it effectively. Current wont matter much.. that'll just determine the time it takes to charge it.
• 

  vishnu priya

  Good idea people!!
• 

  Kaustubh Katdare

  Boy, this is really awesome 😁 ! Freaking great idea, Biswas 😁
  
  Guys what do you think?
• 

  jhbalaji

  If it comes it will definitely get success and also add solar power with it mate...
• 

  Aashish Joshi

  umm..Casio already has a scientific calculator (fx 911 ms) that comes with dual power sources, a battery as well as tiny solar cell..I'm sorry if anyone thinks I'm being rude, but this kinda sounds like reinventing the wheel!!
  
  Instead of a calculator you could maybe think of something that will charge your (cellphone) battery while you walk, using your feet movement to produce current. While this has also been done, but the way it was implemented was not unobstrusive. Technology, in my humble opinion, should be behind the scene!!
• 

  Ashraf HZ

  mad_scientist

  umm..Casio already has a scientific calculator (fx 911 ms) that comes with dual power sources, a battery as well as tiny solar cell..I'm sorry if anyone thinks I'm being rude, but this kinda sounds like reinventing the wheel!!
  
  Instead of a calculator you could maybe think of something that will charge your (cellphone) battery while you walk, using your feet movement to produce current. While this has also been done, but the way it was implemented was not unobstrusive. Technology, in my humble opinion, should be behind the scene!!

  Its not really reinventing the wheel. Its more about relying less on batteries 😀 If its possible to covert human power to electricity, however small it is.. its still a good start.
  
  We do have interesting discussions regarding methods of recharging mobile phones. You can check these threads:
  1) Sound Energy: #-Link-Snipped-#
  2) Sugar Battery:#-Link-Snipped-#
  3) Microwave (wireless) power: #-Link-Snipped-#
  4) Power from footsteps: #-Link-Snipped-#
  
  Lets stick to the topic at hand 😀 Who knows, this calculator idea might spawn into something innovate.
• 

  silenthorde

  Thanks everyone for taking interest.
  
  Most of our calculators come with small Solar cell. But is it really efficient? I have tried working with it..but with limited success.
  
  What i did was...I removed the alkaline battery from one of my Scientific calculators... and used it under a strong light source. But the display was weak.
  
  Nevertheless, it is a good supplement, i Suppose.
• 

  silenthorde

  ash

  Keep in mind that to recharge the li-ion, the charge potential has to be higher than the battery rating. Assuming we are using the common CR2032 cell, you'll need something like 4.5V to charge it effectively. Current wont matter much.. that'll just determine the time it takes to charge it.

  @ASH : How about using a simple charge amplifier...That will convert the charge to it's corresponding voltage. Once it is a voltage, we can sutaibly amlify it using any amplifier of suitable gain to take the voltage to around 4.5V. As you have mentioned, current will simply decide the Charging time.
  
  Or alternatively, we can Charge a Capcitor and wait for sufficient number of keypreses, so that the voltage across the capacitor is close to 4.5V, and then use it to charge the Li-Ion battery.
• 

  silenthorde

  The_Big_K

  Boy, this is really awesome 😁 ! Freaking great idea, Biswas 😁
  
  Guys what do you think?

  Thanks a lot BIGGIE....
  
  Im Biswarup Mukherjee...fondly known as Biswa by my friends😛
• 

  silenthorde

  @ASH:
  
  
  
  Can someone please explain this to me?
  
  [FONT=Verdana, Arial, Helvetica, sans-serif]"Some chargers claim to fast-charge a lithium-ion battery in one hour or less. Such a charger eliminates stage 2 and goes directly to 'ready' once the voltage threshold is reached at the end of stage 1. The charge level at this point is about 70%. The topping charge typically takes twice as long as the initial charge."
  
  [/FONT]#-Link-Snipped-#
• 

  jhbalaji

  silenthorde

  Thanks everyone for taking interest.
  
  Most of our calculators come with small Solar cell. But is it really efficient? I have tried working with it..but with limited success.
  
  What i did was...I removed the alkaline battery from one of my Scientific calculators... and used it under a strong light source. But the display was weak.
  
  Nevertheless, it is a good supplement, i Suppose.

  Mate it also depends on efficiency of solar panel too...