STEP [1] Symptoms The capacitive voltage divider is not working correctly. The X C S of the…

STEP [1]

Symptoms The capacitive voltage divider is not working
correctly. The XCS of the equal-value capacitors should be equal.
The / x XC drops should all be approximately equal. At test point 1,
the voltmeter should read about 2.5 V; at test point 2 about 5.0 V; and at test
point 3 about 7.5 V.

STEP [2]

Identify initial suspect area: If C, were shorted, the V at
test point 1 would be 0 V. The V at test point 2 would be 3.75 V rather than
2.5 V. If C3 were shorted, the V at switch position 1 would be 3.75
V, not 0 V. If C1 were open, the V at switch position 1 would be 7.5
V. If C3

STEP [1]

Symptoms The capacitive voltage divider is not working
correctly. The XCS of the equal-value capacitors should be equal.
The / x XC drops should all be approximately equal. At test point 1,
the voltmeter should read about 2.5 V; at test point 2 about 5.0 V; and at test
point 3 about 7.5 V.

STEP [2]

Identify initial suspect area: If C, were shorted, the V at
test point 1 would be 0 V. The V at test point 2 would be 3.75 V rather than
2.5 V. If C3 were shorted, the V at switch position 1 would be 3.75
V, not 0 V. If C1 were open, the V at switch position 1 would be 7.5
V. If C3 were open, the V at switch position 2 would be 0 V. The
normal voltage at switch position 3 is 7.5 V (the source voltage), which is
what is measured. Without making our first test, we have narrowed the initial
suspect area to C2. If it were open, the circuit would operate
similar to the symptom descriptions.

STEP [3]

Make test decision: Bridge the suspected open capacitor with
a known good one of the same ratings and note any changes in circuit operation.
Well try the quick bridging technique. CAUTION: Make bridging connections with
the power off. Then turn power on and make the necessary observations.

STEP [4]

PERFORM 1st Test: Bridge C2 while monitoring
voltage at switch position 2. When this is done, V measures about 4.8 V, close
to the nominal 5-V normal operation.

STEP [5]

Locate new suspect area: This is not necessary since we’ve
found our problem.

STEP[6]

Examine available data

S T E P [7]

Repeat analysis and testing.

S T E P [8]

Verify that the circuit operates normally by checking the
voltage at each switch position (2 n d , 3 rd , and 4th Tests). C2
was open.