FAQ1160

Answer

One of the fastest loads used during IntelliTune testing at Wavelength Electronics was able to go from 4-28°C in approximately 1.5 seconds. Other loads that could fall into this category would be very small loads, or larger loads with high thermal conductivity that change temperature easily.

IntelliTune uses two user-defined parameters to establish its scanning settings.

1. Temperature Setpoint — defines the range in which IntelliTune is allowed to work during the scan.
2. Current Limits — defines the speed of the initial characterization.

If IntelliTune scans past the setpoint during its initial phase of characterization, IntelliTune will fail its overall characterization.

You can avoid this issue with fast loads by:

• Increasing the temperature differential between actual temperature and setpoint temperature. This gives IntelliTune more room to characterize the load.
• Decreasing your current limits on the TC LAB, in order to shrink the room for error when the IntelliTune scan is running.

For most loads, 5°C away from actual temperature will be sufficient to properly stabilize the load to within your needs. For others, more room to collect data may be required, so the difference between setpoint and actual needs to be larger.

After running IntelliTune 5°C off of actual temperature, check the stability of your load at various setpoints to see if it falls within the tolerance required for your needs.

If the stability is not within your tolerance, either try running the IntelliTune scan again with the setpoint at least 15°C off actual, or decreasing your current limits, then check the stability again. If it is still not within your tolerance, repeat this process by either again increasing the temperature differential, or decreasing your current limits.

Note that the setpoint that is chosen for the IntelliTune scan does not need to be the setpoint that you will be choosing for long-term operation. For example, if ambient temperature is 25°C, and you want to keep your load at 25°C, you will still need to run the IntelliTune scan with a setpoint that is either above 30°C or below 20°C in order to properly characterize the TC LAB’s system response to the load. Once the IntelliTune scan has completed, then the setpoint can be changed back to the desired value for operation. IntelliTune adapts the PID coefficients to the new setpoint.