2017 - 07 - 28
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Basic conceptsa. EMC, EMI and EMSElectromagnetic Compatibility (EMC) means the compatibility of products that are in the same electromagnetic environment (electric field and magnetic field). It has 2 ...
2017 - 07 - 28
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Magnetic circuitThis article tries to introduce PMDC motor’s magnetic circuit by the most acquainted concepts. It also tries to introduce some characteristics and parameters of the motors by means of ...
2017 - 07 - 28
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Basic conceptsMotor is an energy conversion device that converts electric energy into mechanical energy or mechanical energy into electric energy, using magnetic field as media.PMDC motor is an energy...
Typical application

Typical application
According to the characteristics of our motor models, we hereby describe in Typical applicationdetails by means of types of
power supply and motor load.
(1)Classified by input power supply
a. Dry battery, rechargeable battery, small capacity AC/DC adaptor. 
The characteristic of such power supply is that they have large 
internalresistance, There is large voltage drop when the motor is
 applied with load.
The output power of the motor is limited by the capacity of the power supply. 
When designing such motor, motor efficiency is not the only point to be considered.
How to get the largest output power from the power supply is the most important. That is
To say, try to get maximum value of P1=V*I. 
Practically, it is hard to achieve this target considering only the motor parameters. How to properly evaluate
such motors is also a subject to us.
b. Input power supply from voltage divider as resistor or resisor/capacitor.
Typical application                  Typical application
In such circuit, when the current changes, the output voltage changes. In actual application, AC input voltage
is usually 120V-240V. Out of various reasons when the current increases, the resistor R1 or capacitor C will
take more voltage drop. The output voltage is less. Motor speed is therefore lowered. Its operating point and
characteristics will all deviate. The result will be different according to different application of the motors.
Take the well-known hair dryer for example, if the above change happens, air flow decreases. The
temperature of the resistor R1 rises. The resistor gets more voltage drop. The output voltage is lower, making
the situation a vicious circle. The motor will lose its function quickly.
c. Regulated power supply
This is the ideal power supply. The input voltage doesn’t change with the environment or motor load. The
motor’s characteristic is decided by the motor parameter itself. The motor performance data we provide to
our customers are tested under such power supply. In practical application, high capacity accumulator battery
and AC/DC adaptor (variation of V less than 5%) are deemed as regulated power supply.
(2)Classified by motor load
a. Fan load
Startup of the motor with fan load is similar to the startup of the motor with no load. So there is no requirement
to motor’s startup or stall torque. Sometimes we even need to restrict its torque from being too large. The
most important feature of the motor with fan load is the stability and discreteness of its speed in mass
production. The output power is in proportional with the motor speed. If the motor speed deviates a lot, the
motor working characteristics will also deviate a lot. So the characteristic of the load at working point is the
major point we look at. 
b. Winching load
Examples are cable retrieving devices for vacuum cleaners and tube retrieving fixtures for Irrigation machines.
Similar to winching devices, the motor starts to work at its full load. The most important characteristic of such
motor is its stall torque. The consistency of the stall torque is the key point during motor design and fabrication.
Central door lock actuator also belongs to such winching load. Motors with such load usually work at short time working cycle.
c. Linear load
Torque of such load is stable during work. The motor power increases linearly with the motor speed. It may reach its full load at startup. But in most cases it starts up with partial load. Usually it works under rated load for a very long time. We should consider various aspects including temperature rise in motor design. Reciprocating pump is the typical linear load. 
d. Other load
There are still other loads like eccentric wheel, gearboxes that we are not going to discuss in this article.

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