Figure 3-2 and Figure 3-3 below show the lab test setup used to test the TIDA-010950 reference design. A DC power supply is used to provide the 24VDC rail to the input of the board, and a 120VAC-to-24VAC plug in transformer is used to provide power to the 24VAC input of the board.

Figure 3-2 Lab Bench Test Setup I

For the BLDC testing, an end-user damper actuator platform is used. The control is handled by the reference design, but the BLDC motor, Hall sensors, and gear box of the existing product is used to replicate actual use in the field. For the EEV motor testing, an SS2421-5042 pancake bipolar stepper motor is used to replicate an EEV stepper motor.

Efficiency measurements are acquired leveraging an electronic load, in addition to several benchtop multi-meters for reading the input/output voltages and currents under each load step. The load for each buck is incrementally stepped from 100mA to 1A in 50mA step sizes.

Figure 3-3 Lab Bench Test Setup II

The damper or EEV position is adjusted based on the input signal received from either the 0-10V control interface or the 4-20mA control interface. In addition, the EEV can be controlled by the temperature reading from the LMT84 as discussed in the software section.