Which number do you see in the circle on the left?


Click here to check your color blindness...


Thanks to...


You may find this interesting. Sometimes people read 220 kiloOhms instead of 330 kiloOhms, looking at the color band on Resistors.. 

Your suggestions and comments are welcome for improving the contents....



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Block Diagram



Ramp Circuit


Speed Amplifier


Current Amplifier


 Firing Circuit


Power Circuit


Types of DC drives 



 Checking Thyristor


Voltage feedback Vs Tacho feedback


Current Limit


Constant HP & constant Torque


Field Weakening


Using CRO 



Motor runs at full speed


Fuses blow


Hunting in speed


Motor gives jerks


Belts vibrate


Speed control not satisfactory 



Speed drops on load


Motor overheats


Sparking on commutator


DC drives and Power Factor


Your comments and suggestions 


Drive stops all of a sudden 


Motor not able to drive the load


DC to DC isolation