General information articles

• 3 phase A.C. Motor Windings and Connection     
• AC Induction Motor Designs, Types - Worldwide popularity of ac induction motors in numerous applications has led to some standardized motor designs. The National Electrical Manufacturers Association, (NEMA, Washington, D.C.) has developed specifications for so-called NEMA design A, B, C, and D motor types. These designs are based on standardizing certain motor characteristics such as starting current, slip, and specified torque points. This article is a brief rundown on NEMA motor types.     
• Alex's Electronic Resource on motors and accessories - This site had many useful documents on electric motors.     
• Anatomy of an ac induction motor     
• Basic Motor Control Schematics     
• Control by a triack for an inductive load - application note AN308 from     
• Controller provides multimode phase control - inexpensive 16C508 multichip controller can implement a phase controller that provides a two-key, indexed processor for ac power or other discrete, digital-signal applications     
• Dimmer with AC motor? - Normal light dimmers may have some problems with an inductive load, such as a motor. Essentially, the dimmer works by chopping bits out of the AC waveform. Inductors, like the coils in a motor, dislike having the current through them changed abruptly, and produce large voltage spikes which can cause the triac to self-trigger or burn if not properly taken care of. This article tells how to do this.     
• Generate advanced PWM signals using 8-bit �Cs - hot to generate waveforms needed for variable speed three phase motor controlling     
• Identifying Motor Defects Through Fault Zone Analysis - This article has information on three phase AC motor troubleshooting and measuring.     
• Motor Controlling Application Notes from LSI Computer Systems     
• Motor Formulas - check also other     
• Motor Starter Basics: Motor and motor branch circuit short circuit and ground fault protection - Short circuits and ground faults occur when conductors unintentionally contact one another, or a grounded surface due to insulation failure, equipment damage, or human error. Protection is provided by fuses, molded-case circuit breakers (MCCBs), or motor circuit protectors (MCPs) installed on the line side of the motor controller, either as part of a combination starter or separately-mounted.     
• Power Factor Correction - Power factor is the ration 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. A poor power factor due to an inductive load can be improved by the addition of power factor correction, but, a poor power factor due to a distorted current waveform requires an change in equipment design or expensive harmonic filters to gain an appreciable improvement.     
• Rules Of Thumb     
• EUROPUMP Guideline: Safety of Electrical, Submersible Motors     
• Squirrel cage motors - Squirrel cage motors get their name from the appearance of early rotors. They are the most common type of industrial AC electric motor, being rugged and requiring neither a separate DC power source nor slip-rings. They are essentially constant speed devices when energised by a constant frequency AC supply, however electronic speed control is available.     
• Synchronous Motor Operation     
• The Selection, Connection, Reversing and Repair of Electric Motors - Selecting a motor and connecting the electricals are the first challenges encountered after purchasing that long coveted machine tool. There are several types of single phase AC motors in current production in the U.S., but only two types are commonly used in powering home shop machninist equipment.     
• Troubleshooting Adjustable Speed Drives - There are lots of things to look out for when troubleshooting adjustable speed drives, from current and voltage imbalance to single phasing and overvoltages. Here is just a small sampling of what you need to look at, and the test tools you should be using, when troubleshooting ASDs.     
• AC Motor Loads - Table listing electrical operating and full load current at different horse power and voltage levels.     
   

Controlling three phase motors

• Three-phase power regulator - This three-phase linear power regulator can control resistive loads or induction motors. Drive outputs are optoisolated and regulation from zero to full load is via a single potentiometer so interfacing to a PC should be easy, assuming all mains isolation is properly implemented.     
• Solving Motor Failures Due to High Peak Voltages and Fast Rise Times (dv/dt) - The evolution of power semiconductors has been so dramatic that today an insulated gate bi-polar transistor (IGBT) can be turned on in just 0. I micro-second. This results in the voltage rising from zero to peak in only one-tenth of a microsecond. Unfortunately, there are many motors in existence that do not have sufficient insulation to operate under these conditions. When the rise time is very fast the motor insulation system becomes stressed. Excessively high dv/dt can cause premature breakdown of standard motor insulation. Inverter duty motors typically have more phase-to-phase and slot insulation than standard duty motors (NEMA design B).     
• Using VHDL-AMS to model complex heterogeneous systems, part 1 - HDLs bridge the gap between math-based tools and physics-based tools to help you meet model-development requirements. Motion-control-system development poses many challenges for conventional simulation tools. These systems are extremely complex, and they also traverse technology (domain) boundaries as well as analog/digital boundaries. In addition, computers or DSPs control most of these systems in real time, requiring modeling capabilities that encompass both Z-domain transfer functions and software algorithms.
     

Using three phase motor on single phase supply

• Application Notes For Rotary Phase Converter   
• Home Made 3 Phase - one way to generate 3 phase power from single phase supply to run three phase electrical motor   
• Phase Converters - use one phase power to run three phase motor   
• Static Phase Converter Application Notes   
• Understanding and selecting a phase converter - from 1 phase power to 3 phase electrical motor  
   

Circuits

• 230V AC motor controller - controls speed of 230V AC universal motor, in pdf format, text in Finnish     
• Motor Speed Control - allows you to control the speed of an AC motor, for example an electric drill, designed for 115V AC   
• Power Tool Torque Control - 117V AC drill/power tool speed controller circuit   
• Using a Light Dimmer IC For AC Motor Speed Control - This circuit example uses LS7231 Light Dimmer IC   
• Circuit makes simple high-voltage inverter - A simple high-voltage MOSFET inverter solves the problem of driving a high-side MOSFET, using a low-voltage transistor. You can drive the circuit with a single CMOS gate. This circuit is probably the simplest high-voltage inverter you can design. It has served in thousands of three-phase motor drives from 0.37 to 0.75 kW.   

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