07-28-2013 02:14 AM
I'm a new in LabView programming. Currently I have a NI USB 6008 DAQ and want to build a PWM dimmer control for LED lamp. The project suppost have an intelligent rule to dimm the lamp if detect no person in the area. The project also have an GUI to calculate the energy saving by doing that. Here I need the help from the expert because i a new in this LabVIEW. TQ
07-28-2013 10:35 AM
The USB-6008 is not suitable for use as a PWM dimmer for LEDs. The digital outputs are software timed with a maximum rate on the order of 100 Hz. You will also have a significant amount of jitter in the output timing. This would result in unacceptable flickering of the light.
You might be able to use some external circuitry to generate the PWM. Create a sawtooth oscillator operating at a suitable PWM frequency. Ues a comparator with the sawtooth as one input and the Analog Output from the USB-6008 as the other. The output of the comparator becomes the PWM signal to the LED driver.
What kind of sensor will you be using to detect the presence of a person in the area?
Do you need to actually measure the energy or just calculate an estimate based on the commanded LED setpoint?
Is this some kind of school project? We will not do your work for you but are glad to help you learn.
The best way to get help is to ask questions which are as specific as possible and to post the VIs you have tried along with typical data and an explanation of what you expect and what does not work. The more we have to guess what you want, the longer it will take you to get help and the less likely some people will be to help.