Responding to requests from customers who want to test their solenoids with current of either polarity, Geeplus has introduced a new Pick and Hold unit (PHu) that will switch up to 24 A.
The module is easy to use and only requires a simple USB connection to a PC to provide, fast, clear and accurate results. Giving peak power of greater than 1 kW and capable of operating up to 50 V, the new unit provides bipolar forward and reverse excitation of one device, or unipolar excitation of two devices.
While the new PHu module allows the user to optimize excitation conditions for a solenoid device, in
Source: Geeplus situations where large numbers of solenoids are being tested, cost savings in terms of labor, equipment and energy can also be achieved by fulfilling the functions of both a pulse width modulation (PWM) current regulator and oscilloscope.
In use, the device provides a clear, graphic display of the excitation current waveform. This enables the user to precisely calculate the conditions needed to achieve the required force or speed, with minimum power consumption and heat dissipation.
Allowing the user to define ‘pick current,’ ‘pick time’ and ‘hold current’ parameters for the excitation of the device being evaluated, the display typically shows a spike where the solenoid armature hits the end stop (stroke time) followed by some bounce and settling. When setting up parameters, the solenoid can be switched ‘on’ or ‘off’ from the PC.
The test data shows the achieved current values, and the duty cycle of the PWM current control in the pick and hold conditions. It provides some limited diagnosis of problems such as inadequate current capacity of the power supply. When switched on for long periods, the screen also shows the duty cycle of PWM control, as well as the junction temperature of the power device in real time.
The ability to test solenoids in this way enables the user to ascertain whether an appropriate device is being used for a particular application while also determining the excitation conditions needed to achieve the desired performance. It also helps to optimize the choice of device for the application, which creates savings in terms of size, weight and cost.
