# Using a power transistor to regulate voltage to a piezoelectric bender

#### rontc96

Joined Sep 13, 2019
1
Hi all,

First time posting on here. I have a cursory electronics background, but there's some more in-depth aspects to this that I could use some help with. To put this short, I'm looking to power a piezoelectric bender (https://www.thorlabs.com/thorproduct.cfm?partnumber=PB4NB2W), for very short amounts of time. It needs a fairly high voltage, and my initial idea was to use a DC power supply and a voltage regulator (hooked up to software on the computer taking care of the activation details) to control when power was sent to the bender. But, I received advice that a voltage regulator would be a poor choice, because it's not a great idea to send square pulses (so off/on signals), but instead I should be aiming for smoothly varying voltages. The same person advised me to use a power transistor instead, operating it in its continuous range to provide smooth varying power.

Apologies if that was long, but wanted to provide the background details, before my main question: what does it mean to operate a transistor in its continuous range? That terminology doesn't seem to pop up in regard to transistors. so I could use a little help/clarification.

Joined Mar 10, 2018
4,057
Basically think a linear amplifier, where Vout = G x Vin, where G is gain.

A transistor can be operated as a switch, where the above relationship is
not applicable, or as above where Vin and Vout are directly related by a
G factor.

So using it in a linear region -

Slope of the line is the Gain.

Regards, Dana.

#### ci139

Joined Jul 11, 2016
1,797
maybe they have it on the shopping list . . .
Products Home Products Home / Motion Control Electronics / Piezo / Strain Gauge Controllers
Products Home / Technical Resources / Piezoelectric Tutorial
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the problem is Piezoelectric Bimorph PB4NB2W is capacitive and requires an appropriate driver the added design complexity derives from the 150V driving range -

- you might achieve a slow control with single transistor or a cascade but as the speed rises the power dissipation sets aditional demands or (a requirement of) using some specialized driving technique/elements

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