So quick search on google I found that the sg90 servo motor operates at 6V and about 500mA, after calculating the resistor I need with Ohm's law(9V-6V = 3V, 3V/0.5A = 6ohm) and placing it with the servo, it doesn't work, I did all of this on "tinkercad" so here it is.
As countless people before you have discovered, a 9V PP3 battery is totally inappropriate for motors and servos. Use those for smoke alarms.
Use a 5-6V, 1 Ampere power supply (a phone charger works), or 4xAA batteries for the servo. Be sure to connect the grounds.
Tinkercad is dumbcad if it doesn't raise a stop flag.
Use PP3 for fire alarms, TV remotes but nothing else consuming more current than low two digit milliamps.
Using resistors like that is lower than amateur level. Don't try that again.
(the resistor is not the way to reduce voltage in this circumstance - the servo will take different current depending on its load and therefore “see” a range of voltages . 9v may well damage it .)
The way you have wired it any way ( even it worked ) has the servo working with 9v on its power pin side and 3v on its ground pin - so the Arduino would not control it ( 0-5v output )
So I can't power this servo with 9V and resistors? Because I can power a 2.2V LED with 9V battery and resistors if I do the calculation. Also I think the wiring is ok because it worked with 735ohm resistor and didn't showed me an error, but I don't know how.
An LED is constant current, therefore your resistor sees constant current, therefore the voltage across it is constant. Your servo has several modes (static, moving, stalled, to name the 3 most common) which draw tremendously different currents; therefore, the voltage across your resistor will be quite different in the three modes. Static is the lowest current draw, often in the 5-20 mA range; stalled is the largest, typically between 0.5 and 1.5 Amps. If you size your resistor for any one mode, the others will either starve, or see too much voltage.
Generally speaking, a resistor is a poor way to drop voltage when the load is dynamic, as in this case.
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Alright I got it, but would it work if I drop the voltage to 5V with resistors?
Think it through, you've been given the information twice.
Ok seems to work on TinkerCad, just asking because I tried it irl and it didn't work, maybe the wiring was wrong. anyway thanks.
Once more. Calculate the resistor voltages at different current demands from the Servo. You have exactly the same problem as an hour ago.
The voltages changing from 1.5V to 4V when the servo moving, so I changed the resistors to 5ohm and 10ohm and now it's changing from 5V to 5.5V but I don't think the resistors would survive the battery power irl.
You should accept the advice and realise that it just doesn't work that way.
If it works in Tinkercad but not in real life, Tinkercad is wrong, not real life.
The sooner you believe what you've been told, the more time you save. You can't provide 6 V power for a servo using a 9 V power supply and a resistor. The reason is that the servo uses varying amounts of current.
You need a DC to DC converter or a voltage regulator. Possibly you could use a transistor as a voltage regulator, but with your knowledge of electronics designing your own regulator would not be advisable.
Regardless, the 9V battery will not last very long powering a servo, take the previous advise and use 4 AA batteries.
Re enforcing the above :You can’t drop the voltage with resistors , you have been told why , re read !!!
You need a voltage regulator, which provide a fixed voltage independent of the current drawn and a sensible battery !
Tinkercad is not perfect - it didn’t spot the other problem I mentioned with resistor .
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