C-Frame and D-Frame solenoids are logical choices for locks and other security applications where cost is a concern. However, when the additional protection of an enclosed coil is a benefit, then a Tubular solenoid is a good alternative. Tubular solenoids are more robust, and are also often used in place of conventional C-Frame and D-Frame units when increased efficiency is required. 

The majority of applications are usually 12 VDC or 24 VDC. Other operating voltages can be easily achieved with a simple change to the coil wind. Regardless of voltage, adequate current is required to operate the solenoid properly. When additional initial force is required, the solenoid may be briefly pulsed at a voltage higher than the nominal, and then dropped to the 100% duty operating voltage. Usually a PWM or a dual voltage switch able power source can be used. This is known as a simple pick and hold circuit. Rectified AC power can also be used.

Typically the solenoid plunger provides a pull or push motion to create a blocking or interposing action within the lock mechanism. If the solenoid is to remain on continuously, as with a 100% duty cycle unit, the locking mechanism can become warm or even hot to the touch. In these cases consideration needs to be given to thermal dispersion and appropriate insulation for the lock mechanism. It is not recommended that the solenoid itself be the primary locking mechanism when a high level of security is required. There are exceptions, but the increase in the solenoid size and weight for heftier solenoid components may prove to be cost prohibitive.

Depending on the application a magnetic latching solenoid may be used. When the plunger is to remain in the fully energized position for long periods, a latching solenoid has advantages, since there is no current draw required for holding. This may be applicable in designs where power conservation is desired, such as battery powered applications or where tampering is a consideration. In a latching solenoid, the pull force of the permanent magnet supplements the pull force of the coil.

• -Voltage and current available vs. stroke and force required
• -Mechanical shock and vibration
• -Voltage variances as a function of power supply regulation and line loss
• -Avoidance of lateral strain on the plunger
• -Ambient temperature
• -Solenoid temperature