Monday, May 28, 2018

IAM Search

INDUSTRIAL CONTROL HANDBOOK - 2.2 SOLENOIDS AND TORQUE MOTORS

Where stronger forces must be exerted, an electromagnet can be used directly on a ferrous load, or can be used to push or pull a ferrous plunger against a nonferrous load.

A solenoid consists of an electromagnet and sometimes a ferrous plunger. Some solenoids and applications are shown in Figure 2-2. Used as relays, small solenoids allow a low power circuit to move a switch controlling the current in a higher power circuit.

Figure 2-1 Piezoelectrics in ink jet printersFigure 2-1 Piezoelectrics in ink jet printers

Figure 2-2 Solenoids: (a) basic construction, (b) relay switch, (c) solenoid valve, (d) printer pin solenoid, (e) mail diverterFigure 2-2 Solenoids: (a) basic construction, (b) relay switch, (c) solenoid valve, (d) printer pin solenoid, (e) mail diverter


Some solenoids can move heavier loads, such as the spool in a solenoid-actuated pneumatic or hydraulic valve. The larger the coil, the longer it takes to actuate. Solenoids can be made to act more quickly to move light loads, such as pins in a dot-matrix printer, if larger power supplies are used to drive them. These solenoids must be built to withstand the high temperatures they generate. Even larger and slower solenoids are available to move heavier loads, such as a diverter in a mail sorting transport.

Solenoids, because they are electromagnets, do not exert the same force over their whole stroke. In Figure 2-3 we see that some solenoids provide more force at the end of their stroke, while others provide more force at the start of their stroke. Solenoids can be purchased to pull or to push loads. Solenoids that have built-in linear to rotary converters are also available.

Some torque motors contain solenoids. A torque motor is used to apply a rotational force but not a continuous rotation. The solenoids in a torque motor rotate an armature about its axis. If two coils are used as shown in Figure 2-4, some of the non-linearity in the resultant torque can be eliminated. This type of torque motor has inherent limits on how far the rotor can be caused to rotate.

GO TO NEXT PAGE: INDUSTRIAL CONTROL HANDBOOK - 2.3 AIR-POWER ACTUATORS AND SOLENOID-ACTUATED VALVES

GO BACK TO PREVIOUS PAGE: INDUSTRIAL CONTROL HANDBOOK - 2.1 INTRODUCTION

GO TO MAIN PAGE: INDUSTRIAL CONTROL HANDBOOK - TABLE OF CONTENTS

Comments (0)Add Comment

Write comment

security code
Write the displayed characters


busy

Related Articles

Promotions

  • ...more

Disclaimer

Important: All images are copyrighted to their respective owners. All content cited is derived from their respective sources.

Contact us for information and your inquiries. IAMechatronics is open to link exchanges.

IAMechatronics Login