Voice coil motor driver circuit

The driver incorporates surface mount technology to achieve an exceptional power density. This is comprised of a resistor and inductor, similar to our equivalent model of the dc motor. Measurements made using a klippel analyzer on a 6inch midrange driver. If you want to rotate your motor in only one direction, then this is the easiest way to do so. Designed for linear control of voice coil motors, the cn3927 is capable of operating voltage from 2. Supply variance compensation method for switched voltage mode. Precision position control of a voice coil motor using self. The voice coil of a loudspeaker driver exhibits both a series resistance and an inductance. The amplitude of the frequency determines the displacement of the voice coil motor. The si9961a is a linear actuator voice coil motor driver suitable for use in disk drive head positioning systems. Drv201a data sheet, product information and support.

The name voice coil comes from one of its historically first applications. As a result, the electrical equivalent is also much like a loudspeaker or voice coil motor. In the servo system for voice coil motor, the peak current is 1a. Controller controller commutation, direction management controller current management controller speed driver driver fully integrated, control and power stage fan control triac controller. A voice coil is a linear actuator, that moves a mass along a line. Voice coil, the periodical for the loudspeaker industry is free for those who qualify. Description the cn3927 is single 10bit dac with 150ma output current sink capability. The linear range of a voice coil the range within which developed force is 90% of peak force will normally be roughly equal to the difference between the coil length, and the length of the pole. Test bench is an open forum for oem driver manufacturers in the loudspeaker industry and all oems are invited to submit samples to voice coil for inclusion in the monthly test bench column. Design and implementation of pulse width modulation driving. The l6242 is a monolithic integrated circuit in so20 package intended for use as a dual power opera tional amplifier. I am able to drive a lvcm02503801 linear voice coil using a cytron 10a motor driver shield and a spwm sinewave pwm signal but when i add an rc filter i get response in the motor.

The si9961a operates from a 12 v 10 % power supply and delivers 1 a of steadystate output current. The tls2205 integrates a threephase brushless dc motor driver with a linear fullbridge voice coil driver. Acceleration of 500g is possible with custom devices. Optional output slewrate control and spreadspectrum oscillator reduce conducted noise and radiated. The question is how is the voice coil controlled, using a scope on an old drive you can see there is obviously ac present, so i put a circuit togther that reverses the polarity acrross the coil controlled by a pwm output from a pic, it works but the coil gets to its full movement within a small deviation from 50% symmetry, and its just as good. The lv8498ct is a constant current driver ic for voice coil motors that supports i2c control integrating a digitalanalog converter dac. Voice coil motor driver with pwm input, 800 series the 800 series is a high performance, cost effective dc motor driver to implement intelligent motion control. A few examples with calculations of the voice coil impedance will also be given. Linear dc motors, voice coil motors vcm or voice coil actuators vca are the simplest type of electric motors. Essentially this is just an adjustable constant current source, which displaces the lens within its magnetic harness. Because of the backemf drive, it can work on different kinds of motors such as pendulums as shown in this patent, here is a also a good link. The motor shield is a reasonably good match for the voice coil then. Design and implementation of pulse width modulation. Low voltage voice coil motor driver allegro microsystems.

Voice coil impedance as a function of frequency and displacement. A voice coil consisting of a former, collar, and winding is the coil of wire attached to the apex of a loudspeaker cone. The lx7720 provides four halfbridge drivers with floating current sense for motor coil driving, six bilevel inputs for sensing rotary encoders, and a resolver to digital interface with primary coil driver. Low voltage 10bit voice coil motor driver with i2c ionize. The xmega talks to four lv8498ct voice coil motor driver. Oct 01, 2018 the tls2205 is a combination voice coil and spindle motor driver with voltage monitor integrated circuit. Voice coil motors are widely used in the industry owing to their advantages of light weight, lowest price and good repeatability as digital camera and mobile phone camera. Heres a little bit more info on that particular piece of our setup. Cn3927 low voltage voice coil motor driver with i2c interface 1. If the current is minimal then any minimum wire gauge can be used and all will give the same results. Designed for linear control of small form factor voice coil motors, the a3907 is capable of peak output currents to 102 ma and operating voltages to 5. Vcm current is open and shortcircuit protection on vcm controlled with a fixed frequency pwm controller or a output linear mode driver.

A voice coil actuator, also known as a noncommutated dc linear actuator, is a type of direct drive linear motor. Designed for linear control of small form factor voice coil motors, the a3907 is. The weight on the end of the spring represents the mass of the diaphragm the cone and dustcap and the mass of the air that moves with the diaphragm. This study aims to fast move the coil so that the move time can be shortened. Jun 15, 2017 moving coil loudspeaker construction and principle. A bldc fans speed can be varied smoothly, without the usual steps associated with a normal ac fan. Impedance compensation networks for the lossy voicecoil. Supply variance compensation method for switched voltage.

Depending on the how its wired, u2 divides the pendulum drive pulses by 2, 3 or 4. It uses an ultraminiature wlp package and includes a current detection resistor for constant current control, which makes the ic ideal for miniaturization of camera modules intended for use in cameraequipped mobile phones. This device is made possible by a power ic process which combines bipo. The term is also used for voice coil linear motors, such as those used to move the heads inside hard disk drives, which produce a larger force and move a longer. Vcm current is internal current limit for vcm driver controlled with a fixed frequency pwm. I am also not sure what is vs in the equation but i assumed 5 because of the max pwm voltagei really dont know if this is right. This circuit is designed for smallformfactor, highperformance hard disk drives. The dac is controlled via a i2c serial interface that operates dac by clock rates up to 400khz. Drv201 voice coil motor driver for camera auto focus.

Hi, i am new to electronics and am making a simple mistake but do not see it. The si9961a contains all of the power and control circuitry necessary to drive the vcm that is typically found in 31 2 inch hard disk drives and optical disk drives. Internal circuit protection includes thermal shutdown with hysteresis, flyback clamp diode, and undervoltage monitoring. It is particularly indicated for driving inductive loads as linear motor, and finds.

Here power transistor is used as a switch to turn a motor on or off depending upon the applied voltage at base. The problem is i cant get my circuit to work with the parameters i have set. The nature of the voice coil impedance is dependent. Drv201a voice coil motor driver for camera auto focus.

Drive circuit of voice coil motor, method for driving. Pmic motor drivers, controllers integrated circuits. The tls2205 integrates a threephase brushless dc motor driver with a linear fullbridge voicecoil driver. The effect of faraday ring shorting ring usage on voice. In the last log i mentioned the driver circuit for the voice coil. C logic thresholds 10bit dtoa converter 100 a resolution low voltage i. Low voltage 10bit voice coil motor driver with i2c. First, we have the impedance created by the voice coil and terminals. The cn3927 is single 10bit dac with 125ma output current sink capability. I dont think an air core and a ferrite core inductor will produce the same results, because magnetic characteristics will be different for air and. The lv8498ct is a constant current driver ic for voice coil motors that supports i 2 c control integrating a digitalanalog converter dac.

The classic moving coil loudspeaker driver can be divided into three key components. The ic output voltage must be over 350mv to guarantee normal linear operation. The lra can be broken down into two sections of passive components. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it. Brushless dc motor driver full project with circuit. Thanks marcelino, the wire thickness will decide the amount of current the coil can handle. The tls2205 is a combination voicecoil and spindlemotor driver with voltage monitor integrated circuit. Supplied with mounting card for easy wire connection and mounting. The current may not reach the programmed level if there is not adequate headroom in the output circuit. Applying a voltage across the terminals of the motor causes the motor to move to one direction. Moticont provides designs and manufactures linear motors, positioning stages, and fully integrated singlemultiaxis positioning systems including voice coil. The present invention relates, in general, to driver circuits, and, more particularly, to systems and methods for compensating for supply voltage variations to a switched voltagemode vcm voice coil motor power drivers in which an important system variable is controlling the current level in the load.

But a voice coil doesnt primarily move things, it is a consequence of the force it applies. The dac is controlled via a i2c serial interface that operates. Cn3927 low voltage voice coil motor driver with i2c interface. The brushless dc motor driver circuit described here uses a drv10866 driver ic to drive a small bldc fan, without using any position sensors. Integrated circuits ics pmic motor drivers, controllers are in stock at digikey. Engineering acousticstransducers loudspeaker wikibooks. It was specifically developed for applications requiring both high precision and highspeed positioning over a short to medium stroke. Vdd, iload, rload can be adjusted to ensure the device operates in the linear range. There are a number of links off this page to other variants and upgrades. Undervoltage lockout uvlo the drv201 device is an advanced voice coil motor thermal shutdown driver for camera auto focus. Voice coil motors are highly controllable electrical actuators suitable for applications needing only limited displacement. Radtolerant position sensing and motor controller microsemi. Fast operation low electrical inductance, and low moving mass enable fast inflow of current and high acceleration.

The max14570 utilizes a switching output topology to provide high efficiency over the entire input supply voltage range. Regarding the driver op amp tl062,i am planning it as inverter dc coupled but i am not sure. Overview lx7720 rad tolerant spacecraft motor controller with position sensing. It has an integrated da converter for setting the vcm current. Nic neutral inductance circuit focal listen beyond. Voice coil motor driver, 950 series a high performance, dual channel, cost effective dc motor driver to implement intelligent motion control with analog inputs. G2 consulting, a good paper on voice coil actuators. Driving a linear voice coil motor arduino forum index.

To be precise, it pushes and pulls a mass wherever it is along a line. Voice coil impedance as a function of frequency and. Pmic motor drivers, controllers integrated circuits ics. Their basic driver circuit is suitably simple here is a formal 2004 paper based on the above. Positioning control of voice coil motor with shorted turn. A drive circuit, which is mounted on an electronic apparatus having a voice coil motor and drives the voice coil motor, includes. The impedance can be only roughly modelled as a resistor re and an ideal inductance le, the occurrence of eddy currents in these structures usually decreases the inductance of the coil and increases losses at higher frequencies 3. It is sometimes said that voice coils are intended for fast.

Understanding linear resonant actuator characteristics. Design and implementation of a voicecoil motor servo. The max14570 is a highefficiency voice coil motor vcm driver ideal for use in powersensitive autofocus camera applications. The fixed part of the voice coil motor is a permanent magnet and the moving part is the coil.

Reversing the polarity of the applied voltage will move. The voice coil is the motor part of the servo system that positions the heads. The voice coil motor will oscillate at the desired frequency and displacement. This provides a general view of an hdd voice coil actuator. To get rid of the noise, you will have to use a much higher pwm frequency. Learn step by step how the speaker voice coil winding. Differential full bridge half bridge half bridge 10 half bridge 12 half bridge 14 half bridge 15 half bridge 16.

The clock motor driver circuit can be modified to accommodate a 25cm 10, 11. Test bench is an open forum for oem driver manufacturers in the loudspeaker industry and all oems are invited to submit samples to voice. Linear voice coil motors actuators and micro voice coil. This product is driver ic for 1phase brushless motor which used for industrial products like base stations or sever, oa equipment, beauty home appliances and white goods. Andrew has a nice intro to the inner workings of the voice coil on his project. We show you step by step, a simple way to copy and build a voice coil, that has been impossible to find in the market. Open and shortcircuit detection 3 description undervoltage lockout uvlo the drv201a is an advanced voice coil motor driver thermal shutdown for camera auto focus. The portion of the coil which lies outside the airgap field dissipates power as heat but develops no useful force. In the following it is assumed that the resistance is separated and treated as a separate element, that is, not a part of the voicecoil inductance. Inductance variation as a function of the current through the voice coil, which is signaldependent. In this document the effect of these shorting rings on voice coil impedance will be investigated by using simplified approximated models of the loudspeaker driver motor parts. The si9961a voice coil motor vcm driver integrates the active feedback and drive components of a headpositioning servo loop for highperformance harddisk applications. The same motor driver circuit is used in making a simple line follower robot. Moticont provides designs and manufactures linear motors, positioning stages, and fully integrated singlemultiaxis positioning systems including voice coil linear actuators, linear stepper motor, linear induction motor and many more.

Here is an utterly amazing laser shutter driver achieving mechanical shutter rise times of 500 ns. The driver suspension acts like a spring to pull the piston back to the center whenever it is pushed or pulled by the motor the voice coil and components of the magnet circuit. Voice coil impedance as a function of frequency and displacement mark dodd1, wolfgang klippel2, and jack ocleebrown. The ba6832fs is a voice coil motor driver used for moving the heads of hard disc and massstorage floppy disc drives.

Because these examples will be based on highly approximated and simplified models. On motor module design, by induced power, current phase is slipped out and it makes inefficient. The vcs1010 voice coil linear stage is a high performance compact positioning actuator. Motion control products manufacturer of voice coil. Brushless dc motor driver full project with circuit available. To position it, you will need either feedback or a spring to work against, as others have already said. Voice coil motor driver with pwm input, 800 series moticont. Internal circuit protection includes thermal shutdown with hysteresis. The circuit uses the backemf from a single motor coil to drive the transistor, so that one transistor is all that is needed to turn the motor. To drive the voice coil stage ive designed this small circuit board.