4386Views16Replies

Author Options:

How do you use a piezoelectric ceramic to light an LED? Answered

I have a small, round  piezoelectric ceramic sensor made from PZT (Lead Zirconate Titanate) material that I would like to try out to see how much mechanical force I need to apply to light a 5mm LED. The piezo ceramic has already been soldered with two wires (negative and positive). Nevertheless, I am completely new to creating circuits that involve a piezo ceramic. As a result, I have no idea whatsoever on how to properly connect the piezoelectric ceramic to the LED as to light it up. I have connected the two together before and applied force on the ceramic to see if it created some sort of charge, yet nothing occurred.      

16 Replies

user
SoumitaC2 (author)2017-01-02

When I hit the plate, the LED blinks, but the project I need it for, requires a stable glow at least for a few seconds. Will anyone be able to help me understand why that happens and how can I create more stable glow for longer periods of time?

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)2012-08-13

Piezos have a very high output impedance, so high, I suspect you cant' draw enough current to light your led. Try it again, in a very dark room, and after you become dark-adapted.

Select as Best AnswerUndo Best Answer

user
frollard (author)steveastrouk2012-08-13

+1 Flicking the disc should result in a tiny tiny tiny blip on the led.

Adding a transistor amplifier or darlington pair (author search them) can yield enough current to drive the led to full brightness.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)frollard2012-08-13

There IS new silicon, LTC3588 which will pump piezo energy into a cap and give you a regulated supply from it.

Select as Best AnswerUndo Best Answer

user
frollard (author)steveastrouk2012-08-14

I'd like to try one (many) of those :) Sounds like a useful little boost here and there!

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)frollard2012-08-14

Linear Tech have some really cunning energy scavenging parts these days.

Select as Best AnswerUndo Best Answer

user
ZiadT2 (author)steveastrouk2016-02-13

Hello! A bit long enough to bring this topic back to life, i have a Piezo connected to the LTC3588 from linear technologies. Any idea if i can connect a darlington pair circuit at the output of the LTC in order to amplify the 100mA theoretical output current?

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)ZiadT22016-02-13

No, because the energy to amplify comes from a power supply, and you haven't GOT a power supply. You are trying to get something for nothing.

Select as Best AnswerUndo Best Answer

user
ZiadT2 (author)steveastrouk2016-02-14

What if i try to amplify the voltage to 5V and use it as a VCC for the darlington pairs in order to amplify my current...What do you think?

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)ZiadT22016-02-14

What are you trying to do ? It still seems to me you are trying to create something for nothing. You have a finite amount of energy from your piezo.

Select as Best AnswerUndo Best Answer

user
ZiadT2 (author)steveastrouk2016-02-14

Yes this is what i'm trying to do!! just like solar energy harvesting i'm applying it to piezo energy harvesting!! i have 100mA output and i want to amplify it to some 1.5A using darlington pairs and a special circuit for voltage amplification.

What do you think?

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)ZiadT22016-02-14

You can't. You are trying to violate the conservation of energy !

Select as Best AnswerUndo Best Answer

user
ZiadT2 (author)steveastrouk2016-02-17

What do you think if designed 10 LTC energy harvesting boards will i be able to draw that amount on the output?

If you noticed the LTC board harvest currents in microamps and converts it to mA.

Please advise back.

Select as Best AnswerUndo Best Answer

user
Downunder35m (author)ZiadT22016-02-15

The max input of the LTC is 20V, the piezo can supply a few thausand volts but no usable current.
So what exactly is the darlington pair supposed to amplify after the LTC is fried from over-arcing?

Select as Best AnswerUndo Best Answer

user
ZiadT2 (author)Downunder35m2016-02-17

Hello, the piezo that i purchased is the only one compatible with the LTC, never mind the safety issues, mind about the amplification on the output of the LTC and if it is possible...What do you think?

Select as Best AnswerUndo Best Answer

user
The Skinnerz (author)2012-08-13

As Steve suggests, you may be able to get a small flash out of an LED if you give the peizo material a good, sharp tap. Even a 1/2" sugar crystal will make a couple of hundred mV, so no doubt your industrially made stuff is capable of momentarily creating a large enough potential to light an LED.

Just remember that the peizo material will only output energy while being deformed, and not while it is just under a constant stress.

Select as Best AnswerUndo Best Answer