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Topic: Multiple Servo? (Read 6 times) previous topic - next topic

dumbified

ok sure. I guess i'll have to settle for the 5V 1A wall wart until I can find something else. 1A for 5 servos? possible if without load?

cybertim

#31
Oct 21, 2010, 08:34 am Last Edit: Oct 21, 2010, 08:40 am by cybertim Reason: 1
With 5v 1A you will probably get only one working.
AFAIK those servo's draw around 600mah on (heavy) load.
That is 1.8A when all three are busy..

And those wallsocket AC/DC adapters usually have a great voltage droppage when you pull this much Ampere.
So ONE servo will probably work, and with two both will probably try to work and stop/reset all the time because of the voltage drop.

The cheapest way to get those bastards running is using some battery (nimh or lipo) that can handle those Amp. surges.
Or you should buy some decent power supply like a 'lab power supply' that can handle 2A+ but those things are expensive (but they will also be your best friend for life).

What i'm trying atm. (to get 12 servo's running: 6A) is modding an old ATX PC Powersupply that has 3.3v 5v and 12v output. THe 5v output can draw up to 21A (!!). Check out this link for a HOWTO:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply


edit: i see that you're trying to get 5 of them running, that is 3A, so a lab power supply, battery or the atx mod is your only answer. 5 on a wallsocket dc adapter will never work.

Only (maybe) an 15v 1A wall adapter and by putting a (5v or 6v 1A+) voltregulator before each servo, but things will get pretty hot and it will consume lots of wattage.

dumbified

I see. Thanks alot for your information cycbertim and zoomkat. I think I shall get a lipo battery then. I'll most probably make it a standalone anyway in the future :) and maybe some voltage regulators cause from zoomkat's link, it seems they give 7+v. I don't have to worry about too much amp being pulled and damaging servos right?

Grumpy_Mike

If you are implementing the voltage regulator as posted above then you NEED to add some capacitors across both the input and the output. The exact minimum value will be given in the data sheet but at least 0.1uF on each with at least 4u7F on the input as well.

bld

#34
Oct 21, 2010, 03:44 pm Last Edit: Oct 21, 2010, 03:44 pm by bld Reason: 1
I really don't understand that it can be that hard to just see the battery as a illustration of a power supply. It could be anything... Strong solar cell, li-po battery, hamster in a wheel, anything...

The picture was only made to show how to connect an arduino to a power supply, and connect a servo motor without drawing on the on board voltage regulator.

But here you go, just connect your zpm to it, and everything should be fine for, at least, the next 5000 years...


Quote
If you are implementing the voltage regulator as posted above then you NEED to add some capacitors across both the input and the output. The exact minimum value will be given in the data sheet but at least 0.1uF on each with at least 4u7F on the input as wel

As I wrote when I posted the picture the first time too...
captain-slow.dk | non contagious!

cybertim

Today i managed to get 12 servo's working at once (with a custom shield), total of 6A current with a single ATX power supply.
Made a video of it:

http://www.youtube.com/watch?v=HnyU_iUFqC8

Lot's of smoke (almost fire) with the first protoype shield i made..
so be carefull, 6A is a lot of current that can burn your arduino easily.

bld

Current burning the arduino? Shouldn't be possible... The idea with this is that you get all the current away from the arduino...
captain-slow.dk | non contagious!

cybertim

i more or less meant that if the shield (plugged on top of my arduino) got on fire my arduino would also be damaged :P

dumbified

#38
Oct 21, 2010, 06:24 pm Last Edit: Oct 21, 2010, 06:48 pm by dumbified Reason: 1


something like that?


Oh and from previous posts it was stated that we should use 8v and above for use with a voltage regulator. Therefore I have come to this battery: http://www.sgbotic.com/index.php?dispatch=products.view&product_id=391

it's got 1350mAH so im estimating roughly 20 mins of use at 3.5amps for 5 servos yea?

ky3mu4

how can i use 8 servos with nano if it have only 6 PWM outputs Arduino Nano?

PaulS

Quote
how can i use 8 servos with nano if it have only 6 PWM outputs Arduino Nano?

Plug them in anywhere. Servos don't use PWM.

AWOL

See
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1286204498/0#6
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

njkl44

http://www.instructables.com/id/Arduino-Wireless-Animatronic-Hand/

i can power 5 fine from the arduino u can power 3 fine

ky3mu4

ok, thanks for everyone!  :)

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