Hello, I’m fairly new to servos and micro controllers and I’m having a problem. Currently i have my Maestro mini 24 Servo micro controller attached to 24 SpringRC SM-S4303R Continuous Rotation Servos. I have hooked up the power for the micro controller via a Hosa ACD-477 Universal Power Adapter connected to a ac to dc plug which then runs to the power terminal of the controller. my problem is when i plug the power source into the wall outlet random servos turn on and wont stop spinning until i unplug the power source. this problem only occurs when i have around 8 or more servos plugged into the controller though it sometimes varies a bit. any less than that and it works fine. Therefore i think it is a current problem. I have to be able to plug this into a wall outlet or something along those lines since the rig has to be on for several hours straight and cannot die in the middle of use. Therefore I’m curious if anyone has any suggestions on how to power this thing effectively and continually that i could do. If it’s as simple as getting a different adapter please post a link to one you think will work.
any suggestions would be appreciated
Your servo power supply is inadequate. You should plan to provide AT LEAST 1 ampere per moving servo, if the servo is moving any kind of a load. Google “servo current draw” for lots more information on this subject. From the Maestro documentation: [quote]Please consult the datasheets for your servos to determine an appropriate servo power source, and note that a ballpark figure for the current draw of an average straining servo is 1 A.[/quote]
well that’s one of the reasons why im kinda curious, out of the 24 servos only one moves at a time (therefore i thought the power supply would be adequate) when the rig is being operated but just when i plug the thing in a few of the motors just start spinning
The servos draw current even when they are not moving, and noise in the power supply can start them moving. So, the assumption that “only one moves at a time” is not at all realistic.
ok, i have one more question just this morning i kinda randomly tried something and I’m wondering if this goes with what you have been saying. what i did was i plugged in all of the servos while the power was plugged in and the chip was plugged into the computer and i was able to plug in all 24 and the thing works fine but then when i unplug the thing and plug it back in the same problem happens and things start to spin.
How many amperes at what voltage does your servo power supply promise to deliver?
If you have a meter or an oscilloscope, monitor the servo power supply voltage. If it changes at all when things start moving, that is a problem.
Unfortunately, neither Pololu nor the manufacturer’s data sheet provides information regarding the quiescent or active current draw for your servos.