Can two 6V servos be connected in series to a 12V source, or do servos behave differently than regular motors when it comes to voltage?
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\$\begingroup\$ Which servo it is (make and model) and what does the datasheet or manual for it says about usage? \$\endgroup\$– JustmeJun 12, 2021 at 14:54
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\$\begingroup\$ or do servos behave differently than regular motors when it comes to voltage? Yes they do, a servo motor might contain some electronics to actually control the motor. Then the electronics determine how much current the servo will take. If one servo takes more current than the other one then the 12 V will not divide equally and your servos will get confused or maybe even damaged. For 6 V servos, just use a 6 V power source. You can make 6 V from 12 V by using a voltage regulator module. \$\endgroup\$– BimpelrekkieJun 12, 2021 at 14:58
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\$\begingroup\$ That is almost never a solution, motors age and current requirements vary making the division ratio indeterminate. \$\endgroup\$– GilJun 13, 2021 at 3:55
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1 Answer
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I assume you mean RC servos, with a three-wire connection consisting of power, ground, and a PWM signal.
Can two 6V servos be connected in series to a 12V source,
Not if you want them to work. First, the "top" servo in the string will have its signal line referenced to the "bottom" servo's power line; unless you make a special interface, the PWM signal will be wrong.
Even if you did make such an interface, servos expect constant voltage, and take as much current as they need to go to their commanded position. As soon as one servo needs more current than the other, it'll pull its own voltage way down and fail to work. At the same time (since the voltage is shared) the other servo will see too much voltage, and would probably suffer damage from overvoltage.
or do servos behave differently than regular motors
Yes, they do. Servos are a motor, geartrain and control electronics all in one package. They act considerably different than simple DC motors.
when it comes to voltage?
Who says that regular DC motors work "right" when connected in series? There are some applications where they may work "right", but others where they'll be "wrong".
Two DC motors connected in series will tend to have the same output torque, and the sum of their speeds will tend to be fairly constant. If you're trying to drive a pair of loads that have a strongly positive torque vs. speed reaction (i.e., each motor driving a propeller or centrifugal pump) then the motors would tend to settle out at the same speed. But if you're trying to drive a pair of loads that have constant torque, or a negative torque vs. speed reaction, then one motor will start up and "steal" all the voltage from the other motor, which will never start.
answered Jun 12, 2021 at 15:02