# series or parallel?

#### mickey12

Oct 12, 2023
4
I have 9 DC motors that have a no load at 0.1AMP, 0.2AMP rated load, and 1.3AMP stall. The actual load will be very slight for each motor. The power supply is 12v ac/dc adapter. Should I wire in a series or parallel?

#### Delta Prime

Jul 29, 2020
1,642
Welcome to maker Pro.
Should I wire in a series or parallel?
Neither.Wire them diagonally. That is a loaded question!
Filled with cavernous voids in your lack of information. Therefore I will fill in the voids; you have nine motors that operate on 200 volts DC!
See what I'm getting at...
Let's say they're all 12 volt DC motors and you're supplying them with 12 volt DC the max stall current is the one motor that draws the most current & that is 1.3 amps * 9 equals 11.7 amps at minimum 12 volt 11.7 amps
AC to DC adapter or "wall wort"and if they're all on at the same time that Wallwort will burn up.
I believe you're confusing amperage and voltage. What is the voltage of your DC motors and what is the specifications for your wall wort?
Thank you..

#### mickey12

Oct 12, 2023
4
Voltage range for each motor is 6-24VDC. Wall wart output is 3-24V 3A 72w max

#### AnalogKid

Jun 10, 2015
2,843
Parallel - only parallel - no exception

The motors will not have the exact same impedances, so in a series string they will not all see the same driving voltage. Also, the motor design assumes a low impedance power source. Thus, wiring them in series will not deliver consistent performance, and some motors might not start up at all.

Parallel is the only way to go for this.

ak

#### Delta Prime

Jul 29, 2020
1,642
Parallel - only parallel - no exception

Parallel is not going to help you with 3 amps power supply we're is short bus so he can take you to school.
Walwort's not going to cut it kiddo!

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
13,476
Parallel is not going to help you with 3 amps power supply
Check your math: 9 motors, 0.2 A rated current each -> 1.8 A rated current. A 3 A power supply is more than good enough.

The caveat lies here:
• Check the startup current of the motors. When all motors are started up simultaneously, the sum of all startup currents may exceed the 3 A limit of the power supply. If you are lucky, the power supply will go into current limit mode and reduce the output voltage. This may (or may not, I can't tell) be enough for the motors to start up. Once they have started, the current drawn by the motors will be reduced and the power supply should raise the output voltage to the nominal value.
• If one or more motors stall, the combined current again may (or will) exceed the limit of the power supply and the output voltage will be reduced, thus reducing the speed of the other motors, too.
• If the power supply has no overload protection, both the above scenarios may damage the power supply.
• Add individual fuses into the wiring leading to each motor to prevent damage in case of a stall. Use resettable fuses if stalls are expected to be only intermittend.

#### Delta Prime

Jul 29, 2020
1,642
Check your math: 9 motors, 0.2 A rated current each -> 1.8 A rated current. A 3 A power supply is more than good enough
Check my math?
I'm on the fence on that one.
Only because I don't know the application.
(By the way it's good to hear your voice so to speak.) And thank you for the correction but...
Do you have the data sheet for the motors? I'm concerned about your current stall speed. Force times speed or torque times angular speed.P=Fv, P=rw If you are stalled, then your speed is zero. If your speed is zero then your power is zero and your efficiency is zero. I'm hopping to see continuous current stall speed parameter for your motors. If you use the motor for robotics such as a hand and you want to grab something that stall speed current will come into play. Heat will build up and burn out your motor. But I fear I may be an unwarranted two steps ahead.

Last edited:

#### mickey12

Oct 12, 2023
4
See attached specs for motors and power supply

#### Attachments

• motor spec.jpg
46.5 KB · Views: 3
• power supply.jpg
53.1 KB · Views: 3

#### mickey12

Oct 12, 2023
4
These motors will be used for a art project. Each will be turning a small piece of 6mm wire about 3" long. However the motors need to run for a extended period of time with multiple starts and stops (like 3 start/stop cycles per minute). The entire run period will be like 6 hours.

#### Delta Prime

Jul 29, 2020
1,642
Thank you for the information.
I was wrong. Darn it! @Harald Kapp, & @AnalogKid were right.
Thank you all for taking me to school...
Good luck to you kiddo! But I'm staying here & wallow in my incompetence.

#### AnalogKid

Jun 10, 2015
2,843
That's two in one week. You're on a roll - !!!

ak

#### Delta Prime

Jul 29, 2020
1,642
That's two in one week. You're on a roll - !!!

ak

Go Michigan! Big blue!
I'm sure there's more I just couldn't delete them fast enough.

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