FFT Applications
Q-1-7 Quality control based on rotation speed variation of a DC motor or a fan motor
- This application performs quality control based on rotation speed variation level of a DC motor or a fan motor.
The rotation frequency obtained from rotating speed of the DC motor or the fan motor and the number of pulses generated by the rotary encoder (the 600 P/R in the illustration above) are input to the FV-1500 F/V convertor as the center frequency. The FV-1500 outputs deviation from the specified center frequency (corresponding to rotation speed variation) as an analog signal. The CF-4700A performs frequency analysis of the deviation output and block comparison of amplitude levels of the deviation spectrum. In this way, quality inspection is established.
Judgment area block (max: 20 blocks) is set up by the specified frequency range and the upper/lower-limit levels on the power spectrum.The most suitable judgment method can be selected from 6 kinds of judgment methods (level, peak level, peak max, insideMax, partial overall or area rate of content). Also control with a PLC* can be performed using comparator output through the digital I/O function.
The CF-4700A can be connected to a computer through LAN or RS-232C interface and the data can be saved.
Product list
| Model | Product name | Remarks | Qty | |
|---|---|---|---|---|
| 1 | CF-4700A | FFT comparator | 1 | |
| 2 | FV-1500 | F/V converter | 1 | |
| 3 | RP-432Z | Roller encoder | 1 | |
| 4 | RP-0169 | Signal cable for the RP-432Z (5 m) | 1 |