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Key Points of Motor Proposal Making and AC/ DC/ BLDC Motor Characteristic Comparison

2020-04-20 17:10:04 71

Custom AC DC BLDC Motor Engineering.png

1. As a 19-years based professional motor manufacturer, sometimes customer asks how to select motor and what information should provide for tailor-made proposal. The first step to approach Power Motor is a correct decision. Our sales obtained rich experience. Through the following 13 items of specification, we can have well understanding about your needs, so to customize a satisfactory motor solution for you.

 1.1 Small Appliance: e.g: Blender、High-speed Blender、Juicer、Hand-blender、Hand-mixer、Bread Maker、Food Processor、Stand Mixer、Noodle Maker、Soymilk Maker、Coffee Maker、Food Dehydrator、Disposer、Meat Mincer、Electric Knife、Air Cleaner、Can Opener、Knife Sharpener、Oven、Micro-wave Oven.
 1.2 Personal Care:

 e.g: Hair Dryer、Air Brush、Curler

 1.3 Vac. Cleaner: e.g: Dry-type、By-pass Type、Re-chargeable、Up-right、Canister and Hand-held
 1.4 Gardening Tools: e.g: Grass Trimmer、Leaf Blower
 1.5 Medical: e.g: Hospital Bed、Power Chairs、Scooters, Massager、Treadmill、Air-pump
 1.6 Industry e.g: Industrial Robots

2. Countries:

3. Volt/ Frequency:

US/ Canada


South America














4. Performance:

Power (W)

Speed (rpm)Torque (N.m)

5. Outline Dimension:Shaft Dimension

Outer Diameter/

Total Length


6. Basic Construction:

Sheet Metal/ 

Die-cast Bracket


Ball Bearing            

 Plastic/ Metal Fan,

Centrifugal/ Axial Fan

Single Speed/


Single Rotation/


Electric-brake Circuit

7. Magnet Wire:

Stator/ Rotor with


Stator w/ Al-wire, 

Rotor w/ Cu-wire

8. Insulation Class:Class A (105°C)Class E (120°C)Class B (130°C)Class F (155°C)Class H (180°C)Class N (200°C)

9. ProtectorImpedance- protectedThermal FuseCurrent Fuse

ATP/ MTP  Thermostat

10. Special Parts:Hall Sensor Assemblies、 Pinion/ Gear、Mounting Plate/ Bracket、Mounting Ears

11. Special 



12. Project 


New Development

New change 

based on Existing

No Change, 

Only Replacement

13. Annual Volume:50K, 100K, 500K 1000K or more than 1000K

2.Motor selection needs to consider in several ways. It is worth to pay if choose the right motor. Otherwise, take time and spend much are still the unsuitable one. 

Here, we compare the main three categories of AC Universal, PMDC (High Volt DC) and Brushless DC (BLDC) in a simple way, so to let understanding easily.

See Following Picture:


                           AC Universal Motor


                     PMDC Motor(High Volt DC)


                              Brushless DC Motor(BLDC)

 2.1 Comparison in Free Load

Motor CategoriesFree Load
Power InEff.SpeedTorque
AC Universal Motormoderatemoderatehighlow
PMDC Motor(High Volt DC)lowmoderatemoderatelow
Brushless DC Motor(BLDC)highlowmoderatelow

From the above free load condition, the speed of AC Universal Motor is relatively high. This needs to take care if have noise requirements. If need to start motor running in no-load from lower speed, then PMDC motor is a better choice.

2.2 Comparison in Max Eff

Motor CategoriesMax Eff
Power InEff.SpeedTorque
AC Universal Motormoderatemoderatemoderatemoderate
PMDC Motor(High Volt DC)moderatemoderatemoderatemoderate
Brushless DC Motor(BLDC)highhighmoderatehigh

From the above Max Efficiency Point, the performance of AC Universal motor and PMDC motor are basically the same range, also the cost of them is almost the same level, Just the PMDC motor needs rectifier for converting AC voltage to DC, which will be slightly cost impact.

Because of PMDC motor inputs with DC power, the effective value of input power is higher than that of AC Universal motor, so it is more stable with loading and the speed drop with loading increasing is less than AC Universal motor.

The performance of BLDC is particularly strong and can show out its advantage with increased load. However, it needs to be considered that the cost can be more than 10 times, which is why the retail price of home appliance with BLDC is mostly more than RMB1000.

 2.3 Comparison in Max Output

Motor Categories Max Output
Power InEff.SpeedTorque
AC Universal Motorhighlowlow
PMDC Motor(High Volt DC)lowmoderatemoderatelow
Brushless DC Motor(BLDC)very highhighhighhigh

In the maximum output, AC Universal motor and PMDC motor are not recommended to use at this loading point, while the performance of BLDC motor is still strong, the only consideration is the high material cost.

For the traditional products, because of the price is the key point to attract end users, so up to now BLDC is not so common, but through the miniaturization, high-speed and lightweight, the user experience is improved. Also, it is easy to provide variable performance with electronic control. More advantage is the motor life would not be limited by carbon brush in neither Universal AC nor PMDC motor. So it is mostly used in high-end products.

POWER has set up Sales and R&D team of 113+ people, we are get ready to receive your project at any time. Let us to provide reasonable, reliable and well-scheduled planning solutions. Work together with you to launch your good products to the market is our honor. 

Pls contact us now, E-mail: info.power@power-motor.com

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