Chapter 12. Electronic Control Devices Advanced text 2023/2024

RQ1 What is the advantage of using solid-state devices in electronic control systems? -answers Solid-state devices are smaller and more durable. RQ2 Semiconductors are _____ . A. conductors B. insulators C. half conductors D. none of the above -answers C RQ3 Diodes and rectifiers allow current to . A. flow in one direction only B. flow in both directions C. divide paths of flow D. none of the above -answers A RQ4 What is the difference between a diode and rectifier? -answers Current rating. RQ5 A thermistor is a resistor that changes resistance with _____ . A. pressure B. sound C. light D. temperature -answers D RQ6 What are the two types of thermistors and how are they different? -answers They are NTC (Negative Temperature Coefficient) and PTC (Positive temperature coefficient). The resistance of the positive temperature coefficient thermistor increases as the temperature increases. The resistance of the negative temperature coefficient thermistor increases as the temperature decreases. RQ7 What materials are used to make semiconductors? -answers Silicon (Si), germanium (Ge). RQ8 What is a transistor? -answers A Transistor is an electronic device that is composed of n-type or p-type materials and is used as a switch or to amplify a signal. RQ9 The transistor is used _____ . A. as a signal B. to amplify a signal C. both a and b D. none of the above -answers B RQ10 Briefly explain the rectification circuit shown in Figure 12.9. -answers This rectification circuit allows for current to flow in only one direction, thus removing one-half of the alternating current cycle, making it direct current. RQ11 What is the difference between a one-function and a multifunction electronic control device? -answers A one function electronic control device has one function while a multi-function electronic control device would have more than one function. RQ12 Label the following components as one-function (a) or multifunction (b) electronic modules. __ defrost module __ heat pump electronic control module __ electronic timer __ gas furnace electronic control module __ three-phase motor protector __ phase loss monitor __ anti-short-cycling device __ three-phase motor monitor -answers __a__ defrost module __b__ heat pump electronic control module __a__ electronic timer __b__ gas furnace electronic control module __a__ three-phase motor protector __a__ phase loss monitor __a__ anti-short-cycling device __b__ three-phase motor monitor RQ13 What is the purpose of an anti-short-cycling device? -answers An anti-short-cycling device prevents the compressor from rapidly stopping and starting. RQ14 True or False: The conductivity of materials plays an important part in the action of semiconductors. True False -answers True RQ15 How have electronic control modules affected the control circuits for heat pumps and fossil fuel furnaces? -answers Many solid-state modules are being used in the industry today to control the operation of furnaces and heat pumps. RQ16 Solid-state timers can _____ . A. delay on opening contacts B. delay on closing contacts C. have an adjustable delay D. all of the above -answers D RQ17 A semiconductor assist kit is used on a _____ . A. PSC motor B. shaded-pole motor C. three-phase motor D. all of the above -answers A RQ18 True or False: The repair of electronic control modules is often accomplished by the changing of individual electronic components on the circuit board. True False -answers False RQ19 What are the functions of the electronic three-phase motor monitor shown in Figure 12.26? -answers It monitors current unbalance, phase loss, phase reversal, short cycling, and overload. RQ20 What are the functions of an electronic heat pump control? -answers The electronic heat pump control supervises the entire operation of the heat pump system. RQ21 What is the basic troubleshooting procedure used to diagnose a multifunction electronic control module? -answers Checking the inputs and outputs of the control module then determine if the operation of the system is correct. RQ22 Which of the following components are used for flame detection in a residential oil-fired furnace? A. thermocouple B. flame rod C. cad cell D. none of the above -answers C RQ23 True or False: The technician must know the input signals to an electronic module to be able to determine what the output signals should be. True False -answers True RQ24 What are functions of a gas furnace electronic control board? -answers Pilot safety Lockout in the event of flame failure Prepurge Postpurge Blower motor operation Electronic board is used as a control point for safety controls Diagnostics RQ25 Why are electronic control modules used on modern gas furnaces and heat pumps? -answers They produce a more efficient and safer system.