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+-- Forum: Pypilot (https://forum.openmarine.net/forumdisplay.php?fid=17)
+--- Forum: General discussion (https://forum.openmarine.net/forumdisplay.php?fid=18)
+--- Thread: wiper motor drive unit (/showthread.php?tid=1060)
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RE: wiper motor drive unit - seandepagnier - 2019-02-26
It depends on the boat. Boats with two wheels and hydraulic steering can have the autopilot on one of the wheels
Right now I do not have a mechanical mechanism I recommend for it, there are many options. You could add an idle pulley or mount the motor so it hinges and locks to tighten the belt, or slide the belt off each time.
RE: wiper motor drive unit - Marivent - 2019-02-26
Ok. I have a diy rope steering system. At the wheel there is no space for such a motor. I plan to add another rope and put the motor in the back of the boat. It seems not practical to have to go there to engage or disengage the autopilot. I'm thinking of another electric motor which moves the wiper motor to tighten the belt. So I can remotely activate the ap from the helm.
RE: wiper motor drive unit - Marivent - 2019-03-01
What do you think about a electromagnetic clutch of an air compressor of a car? Would it be strong enough to handle the power? Those are really inexpensive and combined with a wiper motor the drive would cost below 50$.
Maybe I'll order one this weekend. I need to build an H-Bridge for the wiper motor. Hopefully I can test it next weekend.
RE: wiper motor drive unit - PaddyB - 2019-03-01
Interesting youtube about H bridge motor control >
https://www.youtube.com/watch?v=hG6ItoPeILo
Really good idea to read the comments as well, circuit will go bang without some changes
RE: wiper motor drive unit - seandepagnier - 2019-03-02
I am not familiar with air compressor clutches from cars, but if you think it can work, try it and report the results!
I think you want the clutch on the wheel, not on the wiper output to minimize friction when it isn't engaged.
RE: wiper motor drive unit - Marivent - 2019-03-02
Yes I will do. Would be nice if you could share the scematic of the H-Bridge matching your controller code. I'll have a look on it tomorrow to see if you use pins mor each direction or one for activation and another for direction.
RE: wiper motor drive unit - Marivent - 2019-03-03
Since I'm waiting for parts I decided to have a look at your motor.ino code.
I designed a circuit for the arduino and the h-bridge depending on the ports
used in your ardunino sketch.
Would you please have examine the circuit and give me feedback if I'm right?
Since I could not attach a picture in this post I uploaded it to imgbb.com and share the link:
scematic
RE: wiper motor drive unit - seandepagnier - 2019-03-05
I am concerned that the default state of the mosfets is on which will cause them to short out and you cannot ground the bridge.
The io pins start as input and will not drive high, so I think you need to invert them.
I don't think the schematic is right.
RE: wiper motor drive unit - Marivent - 2019-03-10
Ah I see. I have accidentally mixed up the N and P channel wiring. I will redesign this later.
I have read that the VNH2SP30 is discontinued. So what do you think about the bts7960b. Could be a good choice for
high current. Is already equiped with a heat sink. Only CE for both bridge sides and either PWM for right or left are rquired.
RE: wiper motor drive unit - seandepagnier - 2019-03-13
It can probably work if you modify motor.ino slightly.