Electro Mechanisms, Inc.
515 West Allen Avenue #15, San Dimas California 91773-1469
Phone: 909-394-9953 Fax: 909-394-0782
Email: info@electromechanisms.com

Application Notes

In miniature solenoids, the most important consideration is force vs. stroke. When choosing the correct solenoid, it is first necessary to determine the force required to move the workload and then determine the travel required to move the load.


If a force of 20 oz is required and the length of travel required is .070, then, by using our force charts, you can determine:

  • SP-75 used in continuous duty cycle will do the job.
  • SP-62 used in a 25 percent duty cycle will do the job.
  • SP-50 used in a 6 percent duty cycle will do the job.

After establishing which solenoids will meet your force to stroke needs, you must also determine the following three factors:

  • The size of the solenoid you require.
  • The duty cycle of operations.
  • The voltage and current available to operate the solenoid.

After you made your optimum choice of solenoid model, there are a few other factors that must be taken in consideration:

A) The ambient temperature of operation. All the force curves are shown at a 20° C. ambient temperature. The normal rise in temperature of our solenoids is 85° C above ambient. Therefore, the percentage of force is determined by using the temperature chart shown in the glossary (Figure 1). For normal operation, with some kind of heat sink, the operating temperature is approximately 105° C. This means the force at that temperature is 78 percent of the force, shown on the curve. Please take this duration into consideration especially where continuous duty cycle is concerned.

B) The reaction time desired. First, the smaller the solenoid the less mass to move, thus there will be a faster reaction time. Second, the shorter the stroke is the faster the reaction time. Third, a solenoid operated at intermittent duty with 4X voltage applied will be approximately four times as fast.

C) Life of the solenoid. In many cases, the life required is beyond the normal life specified. Several extra features may be added to increase the normal life. If you anticipate over 2 million operations, talk to one of our experts to discuss additional features.

Our solenoids are designed for optimum performance for the size of the units. Often, we are asked if we can add more turns to increase the force. This process is self-defeating. The increased resistance due to the additional turn of wire reduces the current. Our materials are the best available in the industry. However, there are several ways to increase the force other than by changing the coil.

  • Shorten the Stroke.
  • Use intermittent duty cycle or pulse the unit.
  • Use the next larger size solenoid for higher wattage.
  • Use a conical plunger for additional forces between a stroke of .050 and .125

After the proper solenoid has been chosen, then you should consider the design options as to mounting, terminals or leads, and special features you may require. Let us know your requirements and we will assist you on finding or modifying the proper solenoid for your desired application.

Fatal error: Class 'ftlink' not found in /home/electro/public_html/wp-content/themes/Electro_Mechanisms/footer.php on line 7