I am preparing to conduct some boat model test experiments using a 1.7m long model and simulating a wind heeling moment by attaching an electric ducted fan with brushless dc motor transversely to a vertical post mounted on the model boat. I am looking to simulate a steady wind moment and a cyclic gusting wind moment from a single fan to heel the model boat over to a given angle which I am hoping can be achieved using the WIG-13118 Servo Trigger.
My questions are:
Do you see any possible issues using the Servo Trigger to drive the Brushless DC Motor (via the ESC)?
As the ESC is setup to supply power (from the BEC) instead of receive power, then for the output connection of the servo trigger do I only need to connect the control pin from the ESC to that point or do I also need to connect a ground wire? Similarly can I simply connect the 5v and ground from the ESC to the servo trigger power supply input to power the servo trigger board?
If i need a ground wire for the servo trigger output is there any problem with having a common ground between input and output on the servo trigger board?
I am not very familiar with logic input signals so will a simple 0-5v square wave signal work as the signal input to the servo trigger board with say a 2 - 3 second period cycle and 1 second period duty?
Just the 1 wire for output, then get power/GND from BEC
There wouldn’t be, unless the GNDs are operating at diff nominal voltages
Or a button like in the guide
The main thing for your use case is that you’ll need to set A and B to their middle, then both will need to be adjusted the SAME direction (normal operation is to reverse a motor by turning them CC+CCW, you want to go the same direction at different speeds)…it outputs a PWM signal so it should work like you’ve described
To give further context, one of the requirements will be to record the on-off input signal time-series data to use as the wind heeling moment input in a math model. This is to validate the math model against the experimental testing. The input signal needs to be a consistent period for my test requirements.
My understanding is to achieve the regular cyclic wind gusting action the best approach is to use a signal generator for repeatable input signal periods (instead of a push button) and the servo trigger board in the bistable mode, that way I can input a square wave signal at the desired wind gust cyclic period and a duty corresponding to the period I want the fan operating at setpoint ‘B’ (gust duration). If I used the toggling mode i’d have to send two signals, the first to activate the change from setpoint ‘A’ to ‘B’ and then second signal to bring it back from ‘B’ to ‘A’. To me it seems to be more complicated to generate that input signal from a signal generator unless a 50% duty is desired, but I need flexibility in the signal duty.
From what I can see the bistable mode can be applied on either the standard or continuous board and my understanding is that as I only want the fan operating in one direction the standard board would give me greater adjustment resolution from 1.0ms to 2.0ms (ie. 0-100% fan speed range over the entire trimpot range) whereas the continuous board would give me reduced adjustment resolution by only adjusting between say 1.5ms and 2.0ms (ie 0-100% fan speed range over half the trimpot range).
Does this sound correct? Please let me know if i’m not understanding the Hookup Guides correctly and thank you for the wiring guidance also.