Hi
I am working on a car related project and would like a few recommendations.
The project involves rotating/ flipping a 7inch round headlight 180 degrees and then back to its position using a on/off switch.
The headlight will be supported at either side with a spindle making it freely rotate.
My plan is to have the servo on the end of one of these spindles providing the 0 to 180 motion.
So basically i would like to make the Servo work when I supply 12v it will go from 0 to 180, when I stop the 12v it goes back from 180 to 0 again, what is the simple solution for this?
The reason I have intended to use 12v is due to the cars output, however I can always use a stepdown if needed.
I’ve thought about using a linear actuator with a disc that will only travel 0 to 180 degrees but after research and watching this groups YouTube tutorials I’m thinking a servo may be more precise.
Hope my first question to the group isn’t to confusing.
Tia
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Hi Kevin
There are a couple of things to appreciate if intending to use a servo.
To move a servo a signal must be applied. This comprises a pulse stream of pulse width 1mSec to 2mSec with 1.5mSec as the centre (90º) position. 1mSec turns the servo 90º one way and 2mSec turns it 90º in the opposite direction. Total movement 180º. Some servos are a bit different to this but that is the basic idea.
These pulses have a repetition period of 20mSec (50Hz).
The servo must be powered and the pulse signal maintained to hold position. Without power the resistance to movement will be determined by the servo construction but it will be free to move.
Don’t really know how you are going to achieve this as with a servo the power has to be there all the time.
You could consider a spring loaded set up where application of the 12V rotate the lamp 180º and when 12V removed the lamp is returned to original position by a spring.
I think this could be done by attaching a bar magnet to the lamp. The 12V could energise an electro magnet positioned so the 2 magnetic fields align when the lamp is in the required position and be returned by the spring when power removed. Fairly simple and not an Arduino or RPi in sight..
Cheers Bob
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Thank you Bob.
I will give it further thought.
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Hi Bob.
I was looking at the “goBILDA servo controller “ on the core website.
I think this may be my solution.
If I am able to program the Servo to travel 180 on power up, and then return to 0 when the power is cut.
I am kinda new to this type of electronics and I’m not sure if my interpretation of the details on this product is correct.
Thoughts?
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Hi Kevin
You will need power to return to 0.
Think about this.
Cheers Bob
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Hi Kevin
Just another small detail. If you are going down the servo path.
It could be that you refer to “0º” this may be CENTRE of travel. You may have to use “+90º” and “-90º” when communicating with a controller. Check this if you seem to get a strange result. Different servos and controllers have different requirements.
Cheers Bob
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