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pump-control.co.nz

AMC Pump Controller - NZ Links

http://www.pump-control.co.nz/link-page.php

New Zealand owned and operated, NO B.S. Advanced Motor Control Ltd. New Zealand based supplier of premium motor control equipment. The correct installation of VFDs minimises the EMC generated. EMC from incorrectly installed VFDs cause severe interference with communications equipment and can damage sensitive electronic circuits. New Zealand based supplier of premium GSM, SMS and text messaging control equipment. Mirus Lineator Harmonic Filters. Guaranteed to meet NZ standards. Horner OCS and PLCs. New Ze...

imphotonics.com

Single Phase Induction Motors

http://www.imphotonics.com/single_phase_m.htm

Single Phase Induction Motors. In order for an induction motor to operate, we need to have a rotor with a short circuited winding inside a stator with a rotating magnetic field. The flux from the rotating field cuts through the rotor winding and induces a current to flow. The frequency of the current flowing is equal to the difference between the rotational speed of the stator field and the rotor. If we now add a second stator winding, physically displaced from the first winding, and apply a voltage equa...

imphotonics.com

Power Factor Calculations

http://www.imphotonics.com/pwrfact1.htm

Power factor is the ratio between the KW and the KVA drawn by an electrical load where the KW is the actual load power and the KVA is the apparent load power. It is a measure of how effectively the current is being converted into useful work output and more particularly is a good indicator of the effect of the load current on the efficiency of the supply system. The second identical triangle is made up of the KW KVA and KVAR vectors. KVA = Line Current x Line Voltage x sqrt(3) / 1000. KW = True Power.

imphotonics.com

PID Control

http://www.imphotonics.com/pid.htm

PID is an enhanced feed back system designed to determine the overall system behaviour. A simple feedback system comprises a single feedback path and is proportional only. Feedback systems are used to reduce or eliminates errors. In a typical PID installation, we have a set point and the PID feedback systems works to keep the output value equal to the setpoint value. It is possible for the setpoint value to be a changing value, but this can add complication. If there is a delay, then the error signal fed...

imphotonics.com

Soft Starters for Induction Motors

http://www.imphotonics.com/sstart.htm

Soft Starters for Induction Motors. Voltage control is achieved by means of solid state A.C. switches in series with one or more phases. These switches comprise either:. 1 x Triac per phase. 1 x SCR and 1 x Diode reverse parallel connected per phase. 2 x SCRs reverse parallel connected per phase. Top of Soft Starter Page. Top of Soft Starter Page. Harmonics awareness and paranoia has drastically reduced the number of SCR-Diode type soft starters on today's market, but they do still exist. The technol...

imphotonics.com

50/60Hz motors on 60/50Hz

http://www.imphotonics.com/motor_50Hz_60Hz.htm

On frequencies other than their Design Frequency. If the voltage applied to the motor is held constant and the frequency is increased, the inductive reactance increases and so the flux reduces. This effectively reduces the maximum torque capacity of the motor and so the motor power rating at the higher frequency remains the same. 60Hz rated motor on 50Hz. 50Hz rated motor on 60Hz. Please post a link to this page using the following HTML coding. Questions and/or comments on this page. L M Photonics Ltd P&...

imphotonics.com

Space Vector Modulation in Variable Frequency Drives (VFDs)

http://www.imphotonics.com/vsd/vsd_04.htm

Space vector modulation is a means of generating a three phase variable voltage, variable frequency PWM output voltage. The inverter comprises six solid state switches, two for each phase with one switch on each phase connecting to the positive rail and one switch connecting to the negative rail. By a combination of switching states of these output switches, we can create a sinusoidal output current. In effect, there are eight states that define six output vectors and two NULL vectors. S0 = 000 : NULL.

lmphotonics.com

Secure Password Store

http://www.lmphotonics.com/passwrd.htm

Secure Password Store is a secure Password database program that stores all your passwords in a secure database. Do you have difficulty keeping track of all your passwords? Do you lose track of all your registration information? Do you want fast axcess to your passwords and registration information? Secure Password Store manages all your passwords and registration information and keeps this information hidden from prying eyes. Registered To and Password fields are encrypted. Print out of database. Visits...

lmphotonics.com

Traditional Induction Motor Starters

http://www.lmphotonics.com/m_start.htm

Traditional Electromechanical Motor Starters. AC Induction motors are traditionally started and stopped by applying and removing the A.C. supply. In some cases, a full voltage start is acceptable, but in many situations, the start current must be reduced, and so a reduced voltage starter is employed. I) Direct On Line. The simplest form of motor starter for the induction motor is the D. Ine starter. The DOL starter comprises a switch and an overload protection relay. Top of Motor Starter Page. The Primar...

lmphotonics.com

Series DC Motor

http://www.lmphotonics.com/DCSpeed/series_dc.htm

Like any other motor, series motors convert electrical energy to mechanical energy. Its operation is based on simple electromagnetic principle by which when the magnetic field created around a current carrying conductor interacts with an external magnetic field, a rotational motion is generated. Parts and Principles of operation of a Series DC Motor. A typical DC motor layout is given in the following diagram:. Series Motor - Electrical Diagram. Speed of DC Series Motors. Series Motor Speed Control.