The performance tables show four columns of typical operating conditions for a given unit. The first two “normal speed, extended period of operation”, presume the stepping solenoids will be pulsed on a continuous basis (round the clock under normal ambient temperature of 20°C with no provision to cool the coil). Here the pulse ‘OFF’ interval is calculated to allow sufficient cooling time (between pulses) to prevent thermal damage.
Most applications, however, call for the stepping solenoid to operate on an intermittent basis, allowing time for the coil to cool while the stepping solenoid is not working. This permits a decrease of the pulse ‘OFF’ interval and a subsequent increase in stepping speed.
The performance information was developed from tests with friction loads, which represent the most severe condition because a constant torque throughout the stroke is required. An inertia load requires a high initial starting torque and a braking action at the end – a task that the Series 50-L Stepping Solenoid is designed to handle. In addition to the clutch brake, it has built-in compensation to reduce velocity toward the end of each step.
The detent torque values shown in the Specifications have already been taken into consideration in the performance tables. Detent torque need only be considered when there is a load against the shaft with no power applied.