Ametek DPA1 Series Installation, Operation And Troubleshooting Instructions page 4

Table of Contents
Figure 3-1 Relationship Between Effective Controller Output Span, GAIN Control
Setting,and PHASE/AMP Output Power Span. ....................................................................... 15
3-9. BIAS/MANUAL CONTROL. ............................................................................................. 16
3-11. B F
IAS UNCTION
Figure 3-2 Controller-Output Span with No Offset Bias Current Introduced ..................... 16
Figure 3-3 Controller Output Span With A -2 Milliamperes of Offset Bias Current
Introduced ................................................................................................................................ 16
3-14. M F
ANUAL UNCTION
3-16. OPTIONAL CONTROLS, INDICATORS, AND DEVICES. ............................................ 17
3-18. OPTIONAL CURRENT LIMIT DEVICE. .......................................................................... 17
Figure 3-4 Comparison of Resistivity/Temperature Characteristics of Common Heating
Element Metals ............................................................................................................................. 18
Figure 3-5 Resistivity/Temperature Characteristics of Typical Silicon Carbide Heating
Element ................................................................................................................................ 18
3-25. OPTIONAL CURRENT INDICATOR. .............................................................................. 19
3-27. OPTIONAL VOLTAGE INDICATOR. .............................................................................. 19
SECTION IV - THEORY OF OPERATION .................................................................................. 21
4-1. FUNCTIONAL DESCRIPTION. ........................................................................................ 21
Figure 4-1 Conduction Angle vs. Voltage Across Load ........................................................... 21
Figure 4-2 Comparison of Conduction Angles and Voltage Across Load ............................. 21
Figure 4-3 SCR's Connected Back-to-Back to Obtain Full Wave Rectification .................. 22
Figure 4-4 Current Flow Through Back-to-Back SCR's and Load ....................................... 22
4-6. POWER SUPPLY CIRCUIT. .............................................................................................. 23
Figure 4-5 Simplified Functional Block Diagram of DPA-1 PHASE/AMP .......................... 23
4-8. SUMMING AMPLIFIER CIRCUIT. .................................................................................. 23
4-10. SOFT START CIRCUIT. .................................................................................................... 23
4-12. SOFT START RESET CIRCUIT. ....................................................................................... 24
4-14. SCR FIRING CIRCUIT. ...................................................................................................... 24
4-16. PULSE SHAPER CIRCUITS. ............................................................................................. 24
4-18. VOLTAGE FEEDBACK CIRCUIT. ................................................................................... 24
4-20. OPTIONAL CURRENT LIMIT. ......................................................................................... 24
4-22. BIAS/MANUAL CONTROL. ............................................................................................. 25
4-24. SUMMARY. ........................................................................................................................ 25
4-26. THEORY OF OPERATION. ............................................................................................... 25
4-28. POWER SUPPLY CIRCUIT ............................................................................................... 25
4-30. BIAS/MANUAL CONTROL .............................................................................................. 26
4-32. SUMMING AMPLIFIED CIRCUIT. .................................................................................. 26
Figure 4-6 DPA-1 PHASE/AMP Waveforms ........................................................................... 27
4-33. SOFT START CIRCUIT. .................................................................................................... 28
4-35. SOFT START RESET CIRCUIT. ....................................................................................... 28
4-37. SCR FIRING CIRCUIT. ...................................................................................................... 28
4-38. PULSE SHAPER CIRCUITS. ............................................................................................. 28
4-40. POWER SCR CIRCUITS. ................................................................................................... 29
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AMETEK HDR Power Systems
Phase/AMP Series DPA1/DCPA1
Document 9100030