problems with servomotors

good since I started with arduino I had no problem when programming leds dc motors but in a matter of servos have some difficulty since more I use servo model hs-311 that are a little stronger than the 7 grams of torque so wanted to see if anyone could help me to see a circuit not directly connect multiple servos to direct feeding arduino but with a separate source with the signal from arduino someone who could help me with schematic or another solution

Hmmmm that was a long sentence to read with no pauses, and I’m not sure exactly what you’re asking, but I think you need the attached.

servo power.png

hmm.. in the image above, looks like the servos are connected in parallel..so shouldnt about 6-7 V be enough to run N number of servo motors??

silvergravel:
hmm.. in the image above, looks like the servos are connected in parallel..so shouldnt about 6-7 V be enough to run N number of servo motors??

Yes exactly: 4.8 to 6 in fact. It's the current which is usually the issue. You need a source which can sustain that voltage at about 1A per motor.

o okay thanks jimbo. so here in india we receive 220 v in our plug points. was thinking of using a 5-6 volt adapter out of the electricity socket. should be a good enough source to sustain the voltage?

or would the 5 v from the arduino board ( connected to the laptop ) be good enough?

silvergravel:
was thinking of using a 5-6 volt adapter out of the electricity socket. should be a good enough source to sustain the voltage?

Budget 1A per servo and then choose an adapter that can provide 6V at that current, say 2 or 3 or whatever amps it adds up to.

silvergravel:
or would the 5 v from the arduino board ( connected to the laptop ) be good enough?

No.... we've all probably used that 5V for testing one micro servo with no load, but as soon as you ask the servo to do any real mechanical work, and / or have more than one servo, it can't provide enough current. From memory- and I may be wrong- the Arduino can provide 0.5A total to everything it's doing, so for all practical purposes, it's no good for servo power.

k got it. thanks so much! one last question it has to be DC right?

silvergravel:
it has to be DC right?

Indeed

thank you very much to Jimboza by the chart now if I can do my project without feeding problems servomotor

thanks jimboZA