Driving piezo actuator - Page 1
Forum section: electronics / beginners

author: behoolder
author_rank: Newbie
timestamp: November 08, 2022, 12:46:34 am
content: Hello!I'm planning to create some simple tip/tilt mirror using three piezo actuators from Thorlabs.This should in principle be a realisation of design Thorlabs gives as application idea:https://www.thorlabs.com/Images/GuideImages/7563_Piezo_Stacks_9.jpgAs an educated guess I choose this one:https://www.thorlabs.com/thorproduct.cfm?partnumber=PA3CKWWith parameters:Displacement (Free Strokeb) @ 100 V 3.0 µm ± 15%Load for Maximum Displacementc 65 N (15 lbs)Resonant Frequencyd 415 kHz (No Load)Impedance at Resonant Frequencyd 600 mOhmAnti-Resonant Frequencyd 510 kHzCapacitance 65 nF ± 15%So the idea is to glue them with, say, epoxy, to a mirror in this triangle fashion, create hw & sw to move it and put it inside imaging setup, say: a telescope. Few pixels of movements in image plane should be sufficient so I do not care for large movement stroke, but I want to update mirror position with at least 100Hz frequency, like having it maximally pointing left and 10ms later pointing max right. Precision is not very important, I guess positioning with +/-10% accuracy will be fine for a start.Now as we already got here I am aware that maybe XY problem... But I think the question itself remains valid:Is there any easy solution to drive such a piezo actuator with such requirements?By easy solution I mean either:- a ready to buy module (like for steppers you have i.e. DRV8825)or- an easy to solder by myself set of elements (like lm298 + some resistors)So far I've found this:https://www.tindie.com/products/Fyberlabs/piezo-haptic-flex-module/But I cannot see DRV2667 to be available to buy anymore, also I am not exactly sure if haptic driver like this would be good for actuator like I wantI can also see something like this:https://pl.farnell.com/maxim-integrated-analog-devices/max77501ewv/boost-driver-2-8-to-5-5v-wlp-30/dp/3941815?st=haptic%20driverBut sorry, 0.4mm balls is much too much for my skill: if it has no leads I cannot solder itAlso it doesn't have analog way from input to output which I'd prefer over playing waveforms. (but maybe it's just prejudice).But maybe all I need is something entirely different?What I've found looking for answers here is this thread:https://www.eevblog.com/forum/projects/need-schematic-to-build-a-piezo-driver-0-150v/msg1388451/#msg1388451But high current (15A???) requirement seems inadequate for my needs. Anyway - maybe all I need is full bridge mosfet driver?I've also read this:https://www.eevblog.com/forum/projects/_high-voltage_-linear-piezo-driver/msg916378/#msg916378But I am not sure also - i do not need big bulky thing, I thought it can be done by something smaller?Sorry for being so unsure about anything: it seems like I have most of pieces somewhere in my brain, but I think I need some external push in the right direction, so please help me!======================And by the way:This is my first post here so please allow me to shortly introduce:I am a C++ developer, having just a little experience with embedded stuff.What I can do is to write a I2c/SPI driver for Arduino for some simple IC, provided with datasheet.Provided with an oscilloscope I can even check if it works.I can solder THT elements if necessary.As a hobby I do astrophotography, but instead of getting actual pictures I mostly do some diy stuff about it: steppers control, optical encoders, control & analyzing software.

author: ledtester
author_rank: Super Contributor
timestamp: November 09, 2022, 03:53:14 am
content: QuoteI watched this crash course in piezo actuators:Piezoelectric Actuator Testing: Displacement vs Voltage -- Photonymous Labshttps://youtu.be/vKC99y3fZjAWould a high-voltage triangle waveform generator work for you? Like it would go from 0V to 100V and back to 0V and then repeat?Concerning TI chips... I found the following chips in stock at TI:- DRV8662- DRV2700- DRV2665(To see TI's inventory levels just create a free ti.com account.)All of these are QFN20 chips. Options for using QFN chips are:- use a QFN socket- apply solder paste with a stencil and reflow- using a hot air soldering gun- buy an evaluation moduleSockets which breakout a QFN package to individual pins are available but also kinda expensive -- like $50-$100 a piece.Here's a good video on hand soldering a QFN package -- also discusses the solder paste/reflow procedure:https://store.curiousinventor.com/guides/Surface_Mount_Soldering/QFNThe eval module for the DRV8662 is $99 and apparently is in stock at TI.This video uses the DRV8662 eval module:Haptic Feedback with Piezo Buzzers! -- Carl Bugejahttps://youtu.be/egLA0GgF3xwIn experimenting with it the guy managed to blow up the DRV8662 and replaced it using a hot air gun.

author: WannesS
author_rank: Newbie
timestamp: January 15, 2023, 03:20:51 pm
content: The TI DRV2667 is ideal for your purpose. 65nF is within spec, especially at only 100Hz, it can probably do a bit more.There's a excel file "DRV8662, DRV2665, and DRV2667 Design Equations (Rev. A)" to validate your parameters.There are 4 parts in the same family:DRV8662 & DRV2700 have only an analog inputDRV2665 & DRV2667 have i²c and analog inputAll of them fit your requirements.The Fiberlabs Piezo Module you found on Tindie would be ideal as a breakout board, but it is still out of stock at the moment.The TI piezo drivers were out of stock for a long time, but are available again since mid 2022, and are now reasonably priced and in stock on digikey and mouser.I suggest you message the seller and ask if they could build another batch.The next easiest solution is a TI evaluation module. The cheapest one in stock is DRV8662EVM. TI will only sell you 1 for $99, mouser has 11 in stock for €130Next best option would be to design and build your own board. The QFN20 is somewhat hand solderable with a fine tip iron, but I would recommend to use solder paste with a 0.1mm stencil.As for the piezo actuators, using epoxy is the best way to attach them. They have a maximum curie temperature, so if you can get actuators with pre soldered wires, and don't use a heat cure epoxy.They don't expand/contract linearly, you'll have to compensate for that in software.