1. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. DC GENERATORS ROTATING MACHINES - SAME CONSTRUCTION AS MOTORS: GENERATORIC RUN = 1 working status of DC machine SUPPLY = EXTERNAL MOVER - mechanical energy GENERATOR - converts mechanical into electrical DC DC GENERATOR = DYNAMO

2. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. CROSS-SECTION VIEW DC MACHINE

3. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. PRINCIPLES OF OPERATION

4. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. GENERATOR ACTION

5. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. MAGNETIZATION CURVE = k.I f F m = N f.I f ~ ~ SATURATION LINEAR REMANENT MAGNETIZATION

6. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. COMMUTATION PROCESS SHIFTED NEUTRAL AXIS

7. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. AUXILIARY COMMUTATION POLES

8. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. ARMATURE REACTION DEFORMATION due to armature reaction MAIN POLES INTERPOLES

9. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. BASIC EQUATIONS OF DC GENERATORS BEHAVIOR DEPENDS ON WINDINGS INTERCONNECTION

10. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. THREE BASIC TYPES OF DC MACHINES SEPARATELY EXCITED SERIES SHUNT (also permanent magnet) COMPOUND MACHINE = combination of shunt and series

11. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. SEPARATELY EXCITED GENERATOR

12. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. VOLT-AMPERE (LOAD) CHARACTERISTICS Difference due to ARMATURE REACTION

13. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. SHUNT GENERATOR

14. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. EXCITATION OF SHUNT GENERATOR ! POLARITY of the field winding !

15. © NOTES - Doc. Ing. Pavel Pivoňka, CSc. COMPARISON OF GENERATORS SHUNT:welding machines