Electrical Systems & Mechanical Components Flashcards
7 cards from real CST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Systems & Mechanical Components flashcards as text
What is the primary function of a shunt resistor in a weighing system's electrical circuit?
Answer: To provide a parallel current path for measurement
A shunt resistor provides a parallel current path that allows measurement of current without interrupting the main circuit.
Which condition would cause a scale's analog-to-digital converter (ADC) to produce clipping errors?
Answer: Input signal exceeding the ADC's reference voltage
Clipping occurs when the input signal voltage exceeds the ADC's reference voltage, causing the converter to max out at its upper limit.
A 4-wire load cell connection differs from a 6-wire connection in that it:
Answer: Lacks remote sense lines to correct for lead wire resistance drops
A 4-wire connection cannot compensate for voltage drops across lead wires, whereas a 6-wire connection uses remote sense lines to detect and correct this error.
When testing insulation resistance on a scale's wiring harness, a reading below which value typically indicates a failure requiring repair?
Answer: 1 MΩ
Insulation resistance below 1 MΩ indicates degraded insulation that can allow leakage currents to corrupt the measurement signal.
What mechanical component absorbs shock loads and prevents overloading of the load cell in a platform scale?
Answer: Overload stop
Overload stops mechanically limit the deflection of the weighing platform, protecting the load cell from forces exceeding its rated capacity.
In a strain-gauge load cell, the Wheatstone bridge becomes unbalanced when:
Answer: Applied load causes differential resistance changes in the gauges
Load application causes tension and compression gauges to change resistance in opposite directions, creating a differential voltage across the bridge output.
Which grounding method is recommended to prevent ground loops in a multi-load-cell scale system?
Answer: Use a single-point star ground topology
Star grounding connects all shields and signal commons to one central point, eliminating the potential differences that cause ground loop currents.