How to Measure Haptic Feedback Vibration Performance

 

Mini Vibration Motor Testing: How to Measure Haptic Feedback Performance

Introduction to Mini Vibration Motors

Mini vibration motors are essential components in numerous modern devices, providing haptic feedback in smartphones, wearables, gaming controllers, medical devices, and automotive systems. Understanding how to test and measure vibration performance is crucial for product designers and engineers seeking optimal user experiences. This comprehensive guide explores vibration testing methodologies and compares different motor types.

mini DC motor vibration test equipment

How Vibration Sensation Is Measured

Key Testing Parameters

Vibration motor performance is quantified through several standardized measurements:

1. Acceleration (G-force): Measured in Gs (9.8 m/s²), this indicates the intensity of vibration. Higher G-values mean stronger vibrations.

2. Frequency (Hz): The rate of vibration oscillations per second, affecting how vibrations feel to users.

3. Resonance Frequency: The specific frequency at which a motor produces maximum vibration output.

4. Rise Time: How quickly the motor reaches its target vibration intensity.

5. Current Draw: The electrical current consumed during operation, affecting battery life.

Testing Equipment and Setup

Professional vibration testing utilizes specialized equipment:

• Accelerometers: Piezoelectric sensors attached to the motor or test surface

• Vibration analyzers: Process signals from accelerometers

• Power supplies and multimeters: Monitor electrical characteristics

• Soundproof chambers: Isolate environmental vibrations

• Oscilloscopes: Visualize vibration waveforms

Comparative Analysis: Flat, SMD, and BLDC Motor Vibration

Flat Coin Motor

coin vibration motor for mobile phone

Flat vibration motors, typically ERM (Eccentric Rotating Mass) design, feature:

• Vibration profile: Omnidirectional, diffuse vibration pattern

• Frequency range: 100-250 Hz typical operating range

• Acceleration: Moderate (0.5-2.0G typical)

• Rise time: Slower (~50ms)

• Applications: Basic notifications, low-power devices

SMD (Surface Mount Device) Motors

SMT motor for phone

These compact, mountable motors offer:

• Vibration profile: More directional than flat motors

• Frequency range: 150-300 Hz

• Acceleration: 0.8-2.5G

• Rise time: Faster than flat motors (~30ms)

• Applications: Wearables, compact IoT devices, smartphones

BLDC (Brushless DC) Motors

BLDC motor for drone 

Advanced linear resonant actuators (LRAs) provide:

• Vibration profile: Precise, directional, and sharper sensations

• Frequency range: 150-200 Hz (narrow resonant peak)

• Acceleration: 1.0-3.5G (higher efficiency)

• Rise time: Very fast (<10ms)

• Applications: High-fidelity haptics, gaming controllers, premium smartphones

Why Some Motors Have Stronger Vibration: Key Factors

1. Higher Rotation Speed (RPM)

• Direct relationship: Vibration intensity increases with rotational speed

• Physics principle: Centrifugal force = m × r × ω² (ω is angular velocity)

• Practical limit: Higher speeds require better balancing and durability

2. Increased Current Supply

• Power input: More electrical power translates to stronger magnetic fields

• Torque relationship: Current ∝ Torque ∝ Vibration force

• Design consideration: Higher current requires robust power management

3. Larger Eccentric Mass (Vibrator)

• Mass effect: Heavier eccentric weights produce stronger vibrations (F = m × a)

• Leverage advantage: Mass placed farther from center increases torque

• Size trade-off: Larger masses require bigger motor housings

4. Additional Contributing Factors

• Resonance tuning: Motors operating at their resonant frequency deliver optimized output

• Efficient transmission: Better mechanical coupling to device chassis

• Quality of bearings: Reduced friction losses increase effective output

• Magnet strength: Stronger permanent magnets improve magnetic flux density

Practical Testing Procedure

Step-by-Step Measurement Process

1. Secure the motor in a fixture that mimics actual device mounting

2. Attach accelerometer to the motor housing or test surface

3. Apply rated voltage using a stable power supply

4. Record acceleration data across frequency sweep (typically 50-500Hz)

5. Measure current draw simultaneously with vibration output

6. Analyze waveforms for consistency and harmonic distortion

7. Test at different voltages to understand performance range

8. Conduct durability tests with extended operation cycles

Industry Standards and Benchmarks

• IEC 60068-2-6: Vibration environmental testing

• ISO 5349-1: Hand-transmitted vibration measurement

• Device-specific standards: Mobile device haptic testing protocols

Optimizing Motor Selection for Applications

Choosing the Right Motor Type

Application	Recommended Motor	Target Acceleration	Key Considerations
Smartphone notifications	BLDC/LRA	1.2-1.8G	Fast response, precise control
Wearable alerts	SMD or small flat	0.8-1.5G	Power efficiency, size constraints
Gaming controllers	BLDC with large mass	2.0-3.5G	Strong feedback, durability
Medical devices	Flat coin	0.5-1.2G	Reliability, low noise
Automotive alerts	High-power ERM	1.5-2.5G	Temperature resistance, reliability

Conclusion

Understanding vibration motor testing methodologies and performance characteristics enables better product design and user experience optimization. The choice between flat, SMD, and BLDC motors depends on application requirements, with vibration strength primarily determined by rotational speed, current supply, and eccentric mass size. Professional testing ensures motors meet specifications while providing the desired haptic feedback quality.

For premium mini vibration motors with characterized performance data and consistent quality, our company provides comprehensive technical specifications and application support. Contact us to discuss your specific vibration motor requirements and testing needs.

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Note: All testing data should be collected under controlled laboratory conditions. Actual performance in end-user devices may vary based on mounting, housing materials, and power management implementations.

Where motor location for better vibration in electronic design

When engineer start a new project that need a mini vibration motor ,we will have a problem that where to put the motor in.

Our suggestion is put the motor in  four coners.

For example for wearable watch.

The motor is installed on the dial and hits the skin on the surface of the arm through the vibration of the motor

Sensory vibration. Based on the above image, there will be non-contact between the 6 o'clock and 12 o'clock directions and the arm

Phenomenon, its physical sensation will decrease. The recommended reference positions are 3 o'clock and 9 o'clock.

*It is recommended to place the motor at a lower height position on the housing, as it will cause direct vibration force

The vibration transmitted to the surface of the lower shell skin can be intuitively experienced.

When designing the structure of the motor:

1. It is necessary to perform avoidance treatment or sizing on its four corners

The handling of yielding on top

2. The bottom part of the position where the 4mm width measurement is placed

Tilt angle treatment or dimensional allowance is required for placement.

3. It is recommended to add double-sided tape to the bottom of the motor for initial fixation.

                                                        by Ji fei holding limited

                                                        www.vibrationmotor.net

Which factors affect motor performance changes?

             What's the factor affect 

               DC motor   

       performance change

The Main factors that affecting micro DC motor performance changes

The performance of a motor is determined by three major factors: 

1. voltage between terminals
2. resistance between terminals
3. magnetic force.

Here, we will provide specific examples to illustrate the various main factors that have an impact on these main factors, namely the deterioration of DC motor performance.

Voltage for  DC motor performance changes:

Only when there is a change in the voltage of the power supply can the performance be directly proportional to the change in voltage.

As shown in the image, when the voltage changes due to the power supply, the rotating line moves in Parallel transport, and the current line almost changes in a straight line. 

However, beyond a certain limit, it is no longer proportional to the voltage.

Power type for DC motor perfomance change:

Comparing a Constant power supply with an attached resistance power supply (a power supply with internal resistance r), 

the attached resistance power supply will experience a voltage drop with the internal resistance r.

The stopping current will initially decrease, and the stopping torque will also decrease, causing a change in the inclination of the rotating line.

Internal resistance of manganese battery (1.5V)
Unit 1 type	0.15~0.20 (Ω)
Unit 2 type	0.25~0.35 (Ω)
Unit 3 type	0.40~0.50 (Ω)

Remarks:A motor can be defined by a generator that generates a voltage proportional to the number of revolutions, as well as a motor terminal resistance in series with the voltage.

Coil for  motor perfomance change:

What has a significant impact on motor performance is the coil size.

When there is a change in the number of coils and the diameter of the coil, the results are different.

If the number of coils is increased, the no-load speed of the motor will decrease proportionally.

If the diameter of the coil is thickened, the stopping torque and stopping current of the motor increase proportionally to the square of the coil diameter. 

However, beyond a certain limit, it is no longer proportional to the square.

Conditions for changing the winding line with the same model

When changing the winding line with a motor of the same model, it is necessary to use similar line product values.

Line product value= φ 2 (twice the diameter of the coil wire) × N (number of coils)

Temperature for  motor perfomance change:

The ambient temperature can affect the magnetic force and coil resistance of the magnet. Therefore, there will also be changes in motor performance.

The degree of change at every 1 ℃ change
The magnetic force of a magnet	ferrites	-0.19%
	Rare earth magnet	-0.13%
Coil resistance		+0.39%

Additional explanation: The impact on the 4-point performance of the motor when the temperature increases

N0: No load RPM

In inverse proportion to the weakening of the magnetic force of the magnet, N0 increases.

I0: No load current

It is inversely proportional to the magnetic force of the magnet, but the loss caused by changes in the viscosity of the bearing oil has a greater impact on I0. 

Therefore, our company assumes that I0 is not affected by temperature changes when making presumptive calculations.

Is: stopping current

Inversely proportional to the coil resistance, if the temperature rises, Is will decrease.

Ts: Stopping torque

Due to the weakening of the magnetic force of the magnet, the current will decrease. Therefore, if the temperature rises, Ts will significantly decrease.

List of Main Factors for Returning to Changes

Types of magnets for motor performance change

There are also various types of magnets, mainly referring to changes in magnetic force.

Because when changing from a wet heterojunction magnet to a dry heterojunction magnet, the magnetic force will weaken,

 causing a decrease in the stopping torque (Ts) and an increase in the number of unloaded rotations (N0).

case for for motor performance change

In terms of the ability of magnets, when the metal shell that maintains the magnetic force is thin, 

the magnetic force will leak out of the shell. The so-called auxiliary casing refers to preventing magnetic leakage in order to ensure the ability of the magnet.

The value of a will vary depending on the leakage degree of the motor's magnetic force or the thickness of the auxiliary casing. 

The difference in the auxiliary casing in our company is approximately 8-12%, and it is considered as a=1.08-1.12.

Phase for for motor performance change

Phase refers to the position relationship between the conversion position of the commutator and the brush and the center position of each magnetic pole of the magnet.

Even if the motor is assembled into a neutral phase in the early stages, during load operation, due to the phenomenon of rotor reaction,

 it will become delayed phase (delayed angle) electrically for a period of time. Delayed angle is a poor condition for motors, 

which will lead to deterioration in efficiency, electrical noise, lifespan, and other aspects. 

As an improvement measure, the phase angle is assembled into an inlet angle, 

which counteracts the rotor reaction during load rotation to maintain a neutral inlet angle motor electrically.

Set the neutral 4-point performance to (N0, I0, Is, Ts), and the performance of the inlet angle to (N0 ', I0', Is', Ts'). 

The performance of the inlet angle will be as shown in the above figure, with a slight increase in no-load speed N0 ', 

while other performance is generally similar. When the variation of N0 'is 12-15 °, the angle of entry is 6-8%.

However, when calculating Ts based on the intermediate torque performance, the angle of entry may become relatively small.

Points to note about the angle motor

If the angle motor is reversed in this state, it will become a delayed angle, leading to deterioration of the rectification effect, 

and adverse factors in terms of electrical noise and lifespan. Therefore, the direction of rotation must be unidirectional.

More information of DC motor,pls refer to:

DC motor overview

spring contact 6mm vibration motor Z0610-TP

 6mm vibration motor Z0610-TP

                                          Spring vibration motor Z0610-TP

Spring contact,easy for assemble.

Vibration motor Z0610-TP drawing:

glucose meter motor,vibration motor

vibration motor Z0610-TP widely used for:

Medical equipment: intelligent kit, Sphygmomanometer, Glucose meter

Electric beauty products: beauty pens, electric facial cleaners, facial massagers, eye protectors

Electric toys: Model aircraft, Quadcopter, aircraft model, UAV

Vibrators: contact lens cleaning machines, electronic equipment vibrations, sex products, mobile phones and fields such as steering gear, precision instruments, robots, etc.

Vibrating Glocose meter motor characteristics:

• rated voltage：1.5V；
• no load current：7mA；
• no load speed：8500r/min；
• stall current：0.046A；
• stall torque：0.64gf.cm

Accepting and providing customized micro dc motor consulting, design, and manufacturing services, we can offer suitable and high-quality DC micro motors for you.

Confidence comes from quality, and service highlights value. Dedicated to serving you!