1. Power Supply Control Feedback Control

2. Power Supply Control Lesson Objectives When you finish this lesson you will understand: Secondary Current Control Phase Shift Heat Control Spot Weld Quality Testing Equipment Monitoring Feedback Control Learning Activities 1.View Slides; 2.Read Notes, 3.Listen to lecture 4.View Demo 5.Do on-line workbook 6.Do Homework Keywords: Transformer, Tap Setting, Primary Current, Secondary Current, Silicon Controlled Rectifier, Electrode Force, Power Factor, Toroid, Hall Effect Transducer, Linear Voltage Differential Transformer, Dynamic Resistance

3. Block Diagram of Single-Phase Spot Welder Spot Weld Main Power Line Contactor

4. Configurations for Spot Welding Transformers (a) Stacked, Shell Type (b) Stacked, Core Type(c) Wound Type

5. Transformer Tap Switch EsEs VpVp

6. Parallel/Series Tap Switches EsEs EsEs EsEs EsEs VpVp S1S1 S1S1 S2S2 S2S2 P2P2 P2P2 P1P1 P1P1 VpVp (a) Parallel (b) Series

8. Rules for SCR Conduction can conduct when anode is + with respect to cathode once initiated, can only be stopped by removal of anode voltage initiated by a pulse on ignitor

9. Phase Shift Heat Control (a) Current Controlled by Tape Settings (b) Current Controlled by Phase Shift Setting

11. Link to: Phase Shift Heat Control Demo

16. Electrode Force Gage

25. Equipment Arrangement Power Supply Strain Gage Signal Conditioner Voltage Leads Tap Displacement Transducer Isolation Box Integration Data Recorder Print Oscilloscope