mobilephone charging using piezo electric crystal

[narayanan]

just read thru the info given in the web page and give ur comments ...


Engineers Bring Self Charging Mobile Phones Closer to Reality

 

[Nigel Goodwin]

just read thru the info given in the web page and give ur comments ...


Engineers Bring Self Charging Mobile Phones Closer to Reality

From a quick scan it makes hardly any claims at all - increasing efficiency by 100% sounds a lot, but increasing almost nothing to twice almost nothing doesn't really help a great deal.

Phones use a considerable amount of power, so you need a fair amount to keep it charged - key pressing and speech contain far too little energy, even if it could be recovered with any degree of efficiency.

As this is supposedly for a Uni final project, get a piezo and measure how much energy you can recover from it - I suspect you haven't done even that most basic step?.

 

[audioguru]

He did measure the output from a crystal as 1147mV but does not understand about current and energy.

 

[shortbus=]

Not all piezos are high voltage. There are piezo "tapes" that are used for guitar pickups. Don't know the voltage ,but they are high impedance and must be buffered.

 

[Conrad Hoffman]

You can learn all sorts of things by looking at energy in and energy out. PZTs produce lots of voltage, but at almost no current. The energy produced is usually next to nothing. There are multi-layer PZTs that can product lower voltage and higher current, but the losses are usually higher. There's lots of energy harvesting research going on, but it's usually directed at sensors and things where the power draw is brief and intermittent, or just extremely low to begin with. If you had a continuously vibrating source, you could attach a PZT to a resonant beam and maybe generate small amounts of power, but the impulses from typing don't amount to a hill of beans. BTW, if you had a conversion device that could generate enough energy from typing, you wouldn't want to type anymore. If you don't understand why this is the case, you *really* need to go back and understand that energy in vs energy out relationship. This is OT, but this is just a small part of the overall alternative energy schemes that so many people are looking at. Most of them are losers right from the start (the schemes, not the people). Go to Don Lancaster's Guru's Lair site and read his analysis' of various PV, hydrogen and alternate energy attempts. If you think hydrogen is a fuel, don your fireproof underwear before reading his stuff.

CH

 

[Externet]

Somewhat old thread, with an update...

Linear technology just came up with this IC LTC3588-1 for piezo harvesting

Linear Technology - LTC3588-1 - Piezoelectric Energy Harvesting Power Supply

From there to recharge a cell, well... will take some piezo tapping. But nanopowered devices may find it an interesting chip.

 

[Vizier87]

omg.. that is some revelation.

Features

* 950nA Input Quiescent Current (Output in Regulation – No Load)
* 450nA Input Quiescent Current in UVLO
* 2.7V to 20V Input Operating Range
* Integrated Low-Loss Full-Wave Bridge Rectifier
* Up to 100mA of Output Current
* Selectable Output Voltages of 1.8V, 2.5V, 3.3V, 3.6V
* High Efficiency Integrated Hysteretic Buck DC/DC
* Input Protective Shunt – Up to 25mA Pull-Down at VIN ≥ 20V
* Wide Input Undervoltage Lockout (UVLO) Range
* Available in 10-Lead MSE and 3mm × 3mm DFN Packages

 

[audioguru]

It looks like you need a pretty big piezo and something to keep hitting it so it has an output. Then the circuit boosts the voltage and charges the 47uF capacitor for a few days. Then the capacitor can produce a current pulse of up to 100mA for a few micro-seconds.
I can't think of anything that needs a pulse so infrequently.

 

[Vizier87]

Well.. it'll be wonderful if it works.

 

[arnoldarnold]

hello,

i want to use Piezo Film Sensor in my Project but the problem is i want to know why we use Charge Converter to get voltage because we can get voltage by attaching register in parallel between the terminal of Piezo film sensor.

 

[Vizier87]

start a new thread, friend. Buy the IC anyway, and tell us if it works.

 

[thiyagarajan24]

my suggession

ya its able to do, since even a piezo electric crystal present in buzzer produces from 3-20v when we give small pressure on it.............
all the for your project

 

[cowana]

That kit linked to at the end of page one store 55mJ of energy when fully charged.

That would power my phone (20mA, 3.7v) for a whopping 0.7s.

Not the best route...

 

[schmitt trigger]

From the original poster:

"hi i like to do an project on automatic mobilephone charging using piezoelectric crystal ... small piezoelectric crystal are placed beneath the keypad and when the user types the keypad it generate electric current which is given to the mobilephone battery

I like to know whether it is possible to do this ...or there gonna be any reverse effect due to this ... plzzzz help me out with this ...this is my final year project so plz help me "

The problem with these threads is NOT the poor O.P request................ He/she is only a hapless student who has been given a dumb assignment by an even dumber teacher.
Now, before anyone flames me.... I agree that good theachers should challenge young minds and make them think out of the box. But give them reasonable projects, by heavens sakes! Otherwise, that poor student may be flunked without reason, become frustrated and decide that, electronics is not for him/her.
A good teacher would have provided a better thought assignment...something like what Linear Tech has outlined in their data sheet:

Piezoelectric Energy Harvesting
Electro-Mechanical Energy Harvesting
Wireless HVAC Sensors
Mobile Asset Tracking
Tire Pressure Sensors
Battery Replacement for Industrial Sensors
Remote Light Switches

But no, instead gave him an assignment that, any person moderately proficient in physics, would know is beyond the feasible.

 

[MikeMl]

Makes you wonder if the teacher is un-knowledgeable or smart like a fox to give what looks to us a dumb assignment?

 

[JimB]

I like to know whether it is possible to do this

The problem with these threads is NOT the poor O.P request................ He/she is only a hapless student who has been given a dumb assignment by an even dumber teacher.

Makes you wonder if the teacher is un-knowledgeable or smart like a fox to give what looks to us a dumb assignment?

The OP is asking whether it is possible, so it could be that he is at the feasibility study phase to try and determine if it is worth the effort and carry on, or, whether he should pick another project.

Also, we do not know whether the project was selected by the teacher or student, several possibilities exist:
1 The teacher assigned the project in ignorance
2 The teacher assigned the project with the expectation that a quick response from the student would be "this is impractical"
3 The student selected the project from a list of possibilities and made a bad choice through lack of experience or understanding
4 The student came up with the idea himself through lack of experience or understanding, and an excess of youthfull exuberance.

Those of us who have been around the block a few times know that this is impractical, but maybe in industry when the boss comes up with a hairbrained idea you cant just dismiss it out of hand, you have to spend some effort and prove that it is a bad idea.

JimB

 

[Vizier87]

what next? "Construct a perpetual motion machine: Final year project plzzzzzzzz help!!!!"
From what I see, this type of dumbness prevails in a lot of institutions where lecturers comes from the same place i.e they did their degree, masters and doctorate in the same place, and they don't need the competitiveness since they already have the "cables" to get their degree completed.