I only want forward-reverse direction control, no speed setting: which model suits me?
If you only want forward-reverse direction or on/off control, the ST42 is designed for that purpose; it is driven by an RF receiver, a manual button or a panel signal. However, the continuous current rating of the ST42 is not stated in the product data; if your current requirement is uncertain or high, the 15 A KS250 or the 30 A PT500 is the safer choice.
The ST42 is a DC motor driver that has no speed setting and performs only direction and on/off control. It can be driven from three different sources: an RF remote control receiver, a manual button, or a panel output signal. Typical fields of use are automatic doors and barriers, mini cranes and lifting mechanisms, DC linear actuators, and in-panel automation.
The point to watch when choosing is current. The continuous current rating for the ST42 is not given in the product data, so you need to measure the current your motor draws and decide accordingly. If there is a chance the measured value exceeds the capacity, move to the models whose figures are explicit:
- KS250: 12/24V, 15 A continuous, 45 A peak (5 s), IP45.
- PT500: 12-24V, 30 A continuous, 40 A maximum (15 s), IP67.
Even if you do not need speed control, there is one more advantage in preferring these two models: thanks to the built-in AntiSwitch you do not need to run an external limit switch for automatic stopping at the end of travel. The ramp feature also reduces mechanical stress on direction changes.
The full topic: DC Motor Driver Selection Guide