Controlling a bunch of vibration motors from a single arduino

Hello all!

My friend and I are working on a class project that involves vibration motors, ones like these to be precise.

We are relatively inexperienced with electronics, and are wondering if there is a proper tutorial on connecting many (10+) motors like these and controlling them with a single pin from an arduino.

Thanks for your time.

Individually on/off, no PWM speed/power control.
A shift register like the TPIC6B595 could control eight <=150mA motors.
No other parts needed except for one power supply decoupling cap per chip.
Those chips can be daisy-chained.
Three control wires needed though.
Leo…

The current draw figures are probably steady-state - at turn on the motors might take more
than 100mA briefly. I’d add a 1N4148 across each motor as a free-wheel diode rather than
risk frying the TPIC6B595.

Alternatively use a 74HC595 driving a ULN2803, this can handle the current, has built in free-wheel
diodes, and will drop the voltage a bit (these motors are designed for 3.7V phone LiPo batteries, so
5V is pushing them rather hard).

You won’t get single pin control from these shift registers, the best you can hope for is 2 pin
control (if you leave the latch pin in transparent mode). You can daisy chain '595 shift registers
so no limit to the number of motors if you have enough power and circuitboard/breadboard.

Use decoupling capacitors - if this means nothing, you need to do some simple research.

MarkT:
The current draw figures are probably steady-state - at turn on the motors might take more
than 100mA briefly. I'd add a 1N4148 across each motor as a free-wheel diode rather than
risk frying the TPIC6B595.

(these motors are designed for 3.7V phone LiPo batteries, so 5V is pushing them rather hard).

  1. The TPIC6*595 has active voltage clamps, so no diodes across the motors needed.
    Peak current of the B version is 500mA.

  2. Use/make a lower supply for all the motors. e.g. a 3.3volt switching regulator.
    Leo..

  1. The TPIC6*595 has active voltage clamps, so no diodes across the motors needed.
    Peak current of the B version is 500mA

Looks like external diodes are still needed to me, but the equivalent circuits may be wrong.

The ULN2803 has these diodes tho.

.

This has been discussed before.
Fig.13 on page 12 from the TPIC6B595 datasheet has a diagram of the fet output stage.
The 50volt zener diode is part of that active clamping circuit.

The disadvantage of darlington arrays like the ULN2803 could be saturation voltage.
Leo..

Does this mean there will be a 50 volt spike?

Adding external diodes wouldn’t hurt, <10 cents each.
.

Wawa:
This has been discussed before.
Fig.13 on page 12 from the TPIC6B595 datasheet has a diagram of the fet output stage.
The 50volt zener diode is part of that active clamping circuit.

The disadvantage of darlington arrays like the ULN2803 could be saturation voltage.
Leo..

There is a limit to the avalanche energy the FETs can take, if you can calculate what that motor
stores you can work out if its safe or not - I know I'd rather not have 50V noise all over the place
interfering with other circuitry for no good reason though.