PRODUCT SPECIFICATION
RC4190
Troubleshooting Chart
Symptom
Possible Problem
Draws excessive supply current on start-up
Battery not "stiff" — inadequate supply bypass capacitor.
Inductance value too low.
Operating frequency (F ) too low.
O
Output voltage is low.
Inductance value too high for F or core saturating.
O
Inductor "sings" with audible hum.
Not potted well or bolted loosely.
Normal operating condition.
L in appears noisy — scope will not synchronize.
X
Inductor current shows nonlinear waveform.
Inductor is saturating:
1. Core too small.
2. Core too hot.
-IMAX
3. Operating frequency too low.
ILX
65-3464-04
Time
Inductor current shows nonlinear waveform.
Waveform has resistive component:
1. Wire size too small.
2. Power transistor lacks base drive.
3. Components not rated high enough.
4. Battery has high series resistance.
-IMAX
ILX
65-3464-05
Time
Inductor current is linear until high current is
reached.
External transistor lacks base drive or beta is too low.
-IMAX
ILX
65-3464-06
Time
Poor efficiency.
Core saturating.
Diode or transistor:
1. Not fast enough.
2. Not rated for current level (high V
SAT).
CE
High series resistance.
Operating frequency too high.
Motorboating (erratic current pulses).
Loop stability problem — needs feedback capacitor from
to V (pin 7), 100 to 1000 pF.
V
OUT
FB
17
RAYTHEON [ RAYTHEON COMPANY ]
