Troubleshooting AC-Turn-On Circuits
Relay AlK1 closes at 2.5 seconds and AC FAULT goes high at 2.9 seconds after 21V UNREG reaches about 13Vdc.
AC FAULT high enables the PWM if OVERVOLTAGE , INHIBIT , and OVERTEMP are also high.
Circuits Included. High AC and AC Dropout Detectors, Bias Voltage Detector, Q11A,
Setup. The Main Troubleshooting Setup, Page 53. Apply the ac mains voltage to the isolation transformer, and set the external supply to 0Vdc.
Inputs: |
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NODE (+) * | SETUP | MEASUREMENT | SOURCE | ||
| 5.0Vdc | A209 (emit.) | |||
| ≈ 21Vdc | A1CR2,A1CR5 | |||
| f.w.rect,0.8V pk | A1CR3,A1CR4 | |||
| TTL sq wave,20KHz | ||||
Outputs: |
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NODE (+) * | SETUP | MEASUREMENT |
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cycle power | ≈ 13.5Vdc |
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cycle power | ≈ 1.4Vdc |
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cycle power | transition 0 to 5Vdc at 25 sec |
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| Hi (5Vdc) |
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cycle power | 2.9 s burst 1.25KHz sq. wave |
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cycle power | one 840ms pulse then Hi at 2.5 sec |
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cycle power | three 420 ms pulses then Hi at 2.9 sec | ||||
cycle power | transition Lo to Hi at 1.7 s |
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cycle power | transition Lo to Hi at 2.9 s |
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AC FAULT |
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cycle power | transition 5.0 to 0.3Vdc at 2.5 sec |
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RELAY ENABLE
*Node( - ) =
Troubleshooting DC-To-DC Converter
Parallel NOR gates A4U1, A4U2 and A4U3A act as drivers and switch on FETs A4Q1,Q2,Q3 and Q4 through pulse transformer A4T1. NOR gate A4U3B turns off the FETs through pulse transformer A4T2 and transistors A4Q5 and A4Q6.
Circuits Included.
Setup. The Main Troubleshooting Setup, Paragraph
57