Slot Technician Questions 1) An atom is made of an inner nucleus of ______________ charged Protons and neutrally charged Neutrons, with an outer shell of _________________ charged Electrons. The protons and neutrons are mostly matter and make up most of the mass of the atom. 2) If the outer shell has only one or two electrons, the outer electrons may be pulled away and move to a neighboring atom with relative ease. This is what makes an element a good ______________ of electricity. These are primarily metals. 3) The Intensity of current flow (I) is measured in ________________. This is a measure of how many electrons are in motion at any specific point in a circuit. 4) The electrical pressure pushing the electrons through a circuit is measured in __________________. This is sometimes called Electromotive Force (EMF), because that is a good description of what it is. The force that moves the electrons. 5) The opposition to current flow is _________________, and is measured in Ohms. 6) Electrical force moves down the wire at ______________________, 186,000 miles per second, or 300,000 kilometers per second, if you prefer. 7) ____________________ have a negative charge and flow from a negative voltage toward a more positive voltage. 8) Electricity that only flows in one direction through a circuit is called ___________. 9) Electricity that flows first in one direction, then reverses, in cycles, is called _________________________. 10) How fast an AC current changes is called its __________________, and is measured in Hertz (or Cycles per Second). 11) What is the formula for Ohm’s Law to find Current? 12) What is the formula for Ohm’s Law to find Voltage? 13) What is the formula for Ohm’s Law to find Resistance? 14) What do we multiply together to find Watts? 15) What is the Peak value for an RMS voltage of 120 V? 16) What is the RMS value for a Peak current of 1 Amp?

17) What is the effective power of your Stereo that is rated at 100 Watts, Peak-to-Peak? 18) What do radio waves, microwaves, heat, light, and cosmic waves have in common? 19) What is the unit of measure for the characteristic of electricity rated in Coulombs per Second? 20) What is the unit of measure for the characteristic of electricity rated in Joules per Second? 21) What component do we use to select the amount of current we want to flow in a circuit? 22) What is the schematic symbol for a resistor? 23) What is the schematic symbol for a battery? 24) What is the schematic symbol for an incandescent lamp? 25) What is the schematic symbol for a wire? 26) What is the schematic symbol for a switch? 27) Current passing through a wire generates a Magnetic Field. (T/F) 28) A magnetic field crossing a wire induces a voltage in the wire. (T/F) 29) How does an increase in secondary current cause an increase in primary current? (100 words or less) 30) Capacitors block DC and pass AC. (T/F) 31) Inductors have a high resistance to AC but a low resistance to DC. (T/F) 32) Resistor color code question. Which of the following resistors would you not be able to buy as a stock part? 1. Red, Violet, Orange, Gold 2. Brown, Black, Black, Red, Brown 3. Red, Green, Brown, Gold 4. Brown, Brown, Red, Silver

33) A red wire with a white stripe would likely be identified as what number? 1. 37 2. 65 3. 41 4. 29 34) What is the normal forward voltage drop you would expect across a silicon diode? 35) You connect an Ohmmeter, set on the Diode Check Scale, across a silicon diode and get a reading of 670. What does the “670” actually represent?

(Assume the transistor has a current gain of 50 for the following questions) 36) R1 is 470 ohms, R2 is 4.7K ohms, VCC = 5 V. About what voltage would you expect to find at the collector of Q1? 37) R1 is 470 ohms, R2 is 1M ohms, VCC = 5 V. About what voltage would you expect to find at the collector of Q1? 38) R3 is 4.7K ohms, R4 is 470 ohms, VCC = 5V. About what voltage would you expect to find at the collector of Q2?

39) Considering the following circuit, complete the Truth Table for the Collector Output. In Out In Out In Out In Out Type of gate? ____________ 0 0 ___ 0 1 ___ 1 0 ___ 1 1 ___

40) Considering the following circuit, complete the Truth Table for the Collector Output. In Out In Out In Out In Out Type of gate? ____________ 0 0 ___ 0 1 ___ 1 0 ___ 1 1 ___

41) Should the above circuit work? What would it accomplish?

42) Will both of these circuits work? 43) Should the circuit to the right work?

44 – 50) Describe the above types of circuits.

51 – 54) Describe the devices as best you can.

55) What kind of waveform would you expect to find at the output of this circuit? 56) What kind of waveform would you expect to find at the output of this circuit? 57) What frequency would the ripple be with a 60 Hz input?

58) What kind of waveform would you expect to find at the output of this circuit? 59) What frequency would the ripple be with a 60 Hz input?

60) Describe the device represented on the right.

61) What is the current limit set for in the above circuit? 62, 63) Describe the two gates being used in the circuit on the right.

64) The picture on the right is a schematic symbol for what kind of device? (Describe it the best you can.) 65) The picture on the right is a schematic symbol for what kind of device? (Describe it the best you can.) 66) The picture on the right is a schematic symbol for what kind of device? (Describe it the best you can.) 67) The picture on the right is a schematic symbol for what kind of device? (Describe it the best you can.)

68) In the circuit above, what would you expect the voltage across the Load Resistor to be like? (Draw it. 69) What hobbies do you have? 70) Do you have a computer? 71) What types of software do you use? 72) Do you get on the Internet? 73) What web sites or forums related to electronics are you familiar with? 74) What web sites or forums related to the Gaming Industry are you familiar with?

75) What magazines related to the electronics are you familiar with? 76) What magazines related to the Gaming Industry are you familiar with? 77) What catalogs related to the electronics industry are you familiar with? 78) What kind of tools do you have at home? 79) What kind of shop setup do you have at home? 80) How do you convert a *.BMP file to a *.PDF format? 81) Under what conditions will the output of the above circuit be High? 82) What is an Interrupt Request line used for?

83) How is a NMI function different from an INT function? 84) What is a Watchdog Timer used for? 85) When searching for a substitute for a Rectifier, what is the difference between a Substitute and an Equivalent part? 86) In the circuit above, what would you expect the output voltage to be under the following conditions? V IN CONTROL V OUT Low Low ______________ High Low ______________ Low High ______________ High High ______________

87) What is the purpose of a Schmitt Trigger gate? 88) A D-Type Flip Flop is what kind of device? A) Astable B) Monostable C) Bi-Stable 89) An oscillator is what kind of device? A) Astable B) Monostable C) Bi-Stable 90) An single shot (one shot) is what kind of device? A) Astable B) Monostable C) Bi-Stable

Assuming diagnostics built into the game allows you to activate the above output at will. 91) With the lamp being burned out, what voltage should you see at J2 while turning the output on and off? 92) Removing the Cable, what voltage would you possibly measure at J2? What would it tell you?

93) Without using a meter, if the lamp did not come on when you turned the output on and off, how could you troubleshoot the circuit with just a wire? 94) What is a Ferrite bead used for? 95) In Microsoft Word, what keystrokes do you use to mark a Table of Contents entry? 96) What program might you use to edit a JPEG file? 97) In Microsoft Word, how do you enter text as super-script, or sub-script? 98) In Microsoft Word, how would you enter the letter “µ” or “Ω”? 99) In Microsoft Word, how do you make Field Codes visible? 100) In Microsoft Excel, how do you specify that the contents of that cell should always be displayed in Scientific Notation?

The next pages refer to Microsoft Excel.

Questions 101 to 109.

Questions 110 to 114.

115) What should Cell A6 be to find the necessary ballast resistor for the LED?

116) Referring to displays, what does LCD stand for? 117) Referring to displays, what does LED stand for? 118) What size is a #73 lamp bulb? 119) What size is a #55 bulb? 120) What kind of base does a #86 bulb have? 121) Referring to lights, what does CCFL stand for? 122) Which is larger, 12 mm or 1/2"? 123) Which is smaller, 10 mm or 1/2"? 124) Which is larger, 13 mm or 1/2"? 125) Which is larger, 5/16"or 3/8"? 126) Which is larger, 1/4" or 5/32"? 127) Which is larger, 24 mm or 1"? 128) Which is larger, 1 meter or 1 yard? 129) In 1/16" increments what is the next larger wrench to 5/8"? 130) Arrange the following from smallest to largest. 1/16", 3/32", 2 mm, 1/4", 0.100" 131) Drilling into wood should you use a high speed or a low speed? 132) Drilling into soft steel should you use a high speed or low speed? 133) Drilling into hardened steel what equipment should you use?

Lead Technician Questions 134) What is the normal voltage likely to be across a CCFL? 6 V 12 V 24 V 60 V 250 V 135) You are troubleshooting a Player Panel Switch on an IGT game. The Common side of the switch shows continuity to ground. You find no voltage on the Normally Open side. What is the problem likely to be? 136) You are troubleshooting a Player Panel Button on an IGT game. When you push the button down the voltage on the Normally Open side of the switch goes High and Low but the lamp doesn't light. Is the button assembly working properly? 137) On a Williams Video game, the touchscreen does not work in the lower right corner where the Cash Out video button should be. Will adjusting the video picture position or brightness help? 138) How can you tell if an Infrared LED is on? 139) When troubleshooting a circuit with a fuse you measure 0 Volts across the fuse with the circuit on. Is the fuse good? 140) A switch with only two contacts is referred to as a __________ Pole, __________ Throw. 141) A switch with three contacts is referred to as a __________ Pole, __________ Throw. 142) A switch with four contacts is likely to be a __________ Pole, __________ Throw. 143) A switch with six contacts is likely to be a __________ Pole, __________ Throw.

144) A SPDT switch, while being activated, will have continuity between the Common and __________ contact. 145) To use a Clamp-On Amp meter should you clamp it around the Hot Lead, Neutral Lead or Both Leads? 146) On a Bally video game what would you use the PIO Test for? 147) On a Bally video game what test would you use to check the Hopper Level Probe? 148) On a Bally video game how do you check to see if the battery on the MPU board is low without pulling out the MPU? 149) On a Bally video game how would you check the Coin Deflector? 150) How do you check to see if the Serial I/O port for the Ticket Printer or Bill Acceptor is working? 151) The CC-62, like many Coin Acceptors and Comparators, has both a Sense Output and a Credit Output. What is the difference between them?

Bench Technician Questions 152) As current through a forward biased diode increases what does the voltage across it do? 153) When evaluating a transistor as a substitute what things should you take into consideration? 154) On a Dot Matrix display, like those used on progressive games, how many elements are used for each dot? What color are they? 155) On a board you find a device with an SOT-23 case and the lettering "1A". What type of device is it? 156) What transistor would more likely be used to drive a Diverter Solenoid? 2N2222 2N2907 1N4148 TIP122 157) What transistor would more likely be used to drive an LED connected to a high rail voltage? 2N2222 2N2907 1N4148 TIP122 158) What diode would more likely be used as a rectifier for a 120 Volt power supply rated at 1 Amp? 1N4148 1N270 1N4004 1N5401 159) What diode would more likely be used as a rectifier for a 10 Volt power supply rated at 3 Amps? 1N4148 1N270 1N4004 1N5401

160) What type of device is an H11AA1? 161) What type of device is an MOC3031? 162) What type of device is a 2N3906? 163) What type of device is a 2N3904? 164) What type of device is a 1N4148? 165) What type of device is a 1N5403? 166) What type of device is a 1N4004? 167) What type of device is a 1N5819? 168) What type of device is a 2N5060? 169) What type of device is an MCT-6? 170) What type of device is a TIP-31? 171) What type of device is a 2N2222? 172) What type of device is a 2N2907? 173) The NTE substitution guide crosses a 1N4002 to an NTE116. It also crosses a 1N4004 to an NTE116. Can I use a 1N4002 as a substitute as a 1N4004?

174) A zener diode rated at 12.0 Volts with 20 mA going through it will have what voltage across it with 5 mA going through it? 11.5 Volts 12.0 Volts 12.5 Volts 0 Volts Source Voltage 175) A zener diode rated at 12 Volts will have what voltage across it if only 6 Volts is applied? 12 Volts 6 Volts 0 Volts 5 Volts 176) An MCT-2 (Opto isolator, DC in, Phototransistor output) has 1.4 Volts across pins 1 and 2. The ballast resistor is a 180 Ohm resistor connected to 5 Volts and has 3.6 Volts across it. What should the voltage at the output of the MCT-2 be? 177) In a circuit you are troubleshooting you have an MCT-2 optoisolator. At pin 1 you measure +5 Volts. At pin 2 you measure 0 Volts. The output is High. What do you conclude? 178) On a 2N3906 transistor you measure +5 Volts at the Emitter, +4.9 Volts on the Base and 0 Volts on the Collector. Is the transistor good? 179) On a 2N3904 transistor you measure 0 Volts on the Emitter, +0.6 Volts on the Base and 0.2 Volts on the Collector. Is the transistor good? 180) On an N-Channel MOSFET transistor you measure you measure +5 Volts on the Gate, 0 Volts on the Source and 0.2 Volts on the Drain. Is the transistor good? 181) You are troubleshooting a microprocessor. You find VCC at +5 Volts. The oscillator has pulses on it at a high frequency. The Address and Data lines show no signals on them. The Reset* line reads 0.1 Volts. The NMI line reads 0.1 Volts. The INT* line reads +4 Volts. The WAIT* line is High. Is the microprocessor working right? Where would you start troubleshooting?

182) You are troubleshooting a microprocessor. You find VCC at +5 Volts. The oscillator has pulses on it at a high frequency. The Address and Data lines are hung at various legitimate High and Low levels. The Reset* line reads +4 Volts. The NMI line reads 0.1 Volts. The INT* line reads +4 Volts. The WAIT* line is Low. Is the microprocessor working right? Where would you start troubleshooting? 183) You are troubleshooting a circuit with a PIC12C509. One of the output lines is reading a flat line at 1.2 V DC on the oscilloscope. How would you proceed? 184) You are troubleshooting a circuit with a Z80180 microprocessor (which is on a socket) with an active Watchdog Timer circuit. The circuit runs in a repeating loop. The oscillator is running. You pull the Reset* line Low with a jumper and scope the pins around the chip. You find it referencing an address of 0x0800. Is this good? 185) You are troubleshooting a circuit with a ULN2803AN whose outputs are connected to a header that would normally go to player panel lamps, but that connector is not in place at this time. With the circuit powered up some of the inputs to the ULN2803AN are showing activity, but none of the outputs are moving. Is the ULN2803AN bad? 186) You are troubleshooting a circuit with an H11AA1 whose inputs connect to a 60 Hz AC signal. The output has an RC circuit on it. Resistor of 1.5K Ohms is tied to +5 Volts, and a 10 uF capacitor to ground. Also connected to the output is the Base of an NPN transistor. With power on the output of the H11AA1 is constantly Low. What does this circuit accomplish? Is it working correctly? 187) You are troubleshooting a 74LS00 (Quad 2-input NAND gate). The input to one side is pulsing. The other input is constantly Low. The output is constantly High. Is the gate working properly? 188) You are troubleshooting a 74HCT02 (Quad 2-input NOR gate). The input to one side is pulsing. The other input is constantly High. The output is constantly Low. Is the gate working properly?

189) You are troubleshooting a 74C74 (D-Type Flip Flop). The D-input is pulsing. The Clock input is pulsing. The Clear* input is Low. The Preset* input is Low. The Q output is Low. The Q-Not output is Low. Is the gate working properly? 190) You are troubleshooting a 74LS74 (D-Type Flip Flop). The D-input is pulsing. The Clock input is pulsing. The Clear* input is Low. The Preset* input is High. The Q output is High. The Q-Not output is Low. Is the gate working properly? 191) You are troubleshooting a J-K Type Flip Flop. The Clock input is pulsing. The J and K inputs are both High. The Q output is High. The Q-Not output is Low. Preset* and Clear* inputs are High. Is the gate working properly? 192) You are troubleshooting a 74LS32 (Quad 2-input OR gate). The input to one side is pulsing. The other input is constantly Low. The output is constantly High. Is the gate working properly? 193) You are troubleshooting a 74LS08 (Quad 2-input AND gate). The input to one side is pulsing. The other input is constantly High. The output is constantly Low. Is the gate working properly? 194) You are troubleshooting a 74LS373 (Octal Latch) The Clock input is High. The Output Enable* input is Low. The outputs are changing with the inputs. Is the 74LS373 bad? 195) You are troubleshooting a 74LS86 (Quad 2-input Exclusive-OR gate). The input to one side is pulsing. The other input is constantly High. The output is constantly Low. Is the gate working properly? 196) You are troubleshooting a 74S138 (3-bit Binary to 1-of-8 Decoder, active low outputs). The A, B and C inputs have 0, 1 and 1 on them, respectively. The EN* inputs are Low. The EN input is High. Which output should be Low?

197) You are troubleshooting a Decade counter. The outputs count as follows: DCBA 0000 0001 0011 0100 0101 1000 1001 1010 1011 1100 1101 0000 Is the counter counting correctly? 198) You are troubleshooting a 4-bit binary counter the Input is a square wave with a 1 microsecond time period. The "D" output stage has a square wave with a period of 0.016 milli-seconds. Is the counter working properly? 199) You are tracing out a circuit and find a 7414 (Schmitt Trigger Inverter) with a capacitor on the input to ground and a resistor feeding back from the output to the input of the same gate. What does this circuit do? 200) You are troubleshooting a CC-16 Coin Comparator and the output of the Null Detector Amplifier is Low all the time. You have a reference coin inserted, but no other "inserted" coin. Is this normal? If this is not normal how would you proceed in troubleshooting? 201) Ypu are troubleshooting a game that does not accept coins. You open the door. The Coin Comparator (CC-16) has an LED lit. It does not accept coins. Is this right or wrong? What should you do or check? 202) You are troubleshooting a Voltage Comparator. The Inverting input is at 0.7 Volts. The Non-Inverting input is 1.2 Volts. What should the out be?

203) You are troubleshooting an audio amplifier (LM358, Inverting Amplifier configuration). You have a signal on the input side of the input resistor (10 K Ohms) of 1 Volt Peak-to-Peak. Ground on the Inverting and Non-Inverting inputs. The Feedback Resistor is a 20K Ohms resistor. Does this indicate a problem? What should the output look like? 204) While troubleshooting a board you find a bad SOT-23 cased diode. The label indicates that the device is a BAS70-04 (Schottky diode). Pin 1 is not used. Your parts list indicates that you have BAS70-W, BAS70, BAS70-05 in stock. Which of these would you use? 205) What is a Glass Passivated diode? 206) You are troubleshooting a 12 V DC power supply with an LM7812T as the regulator. Your meter measures 13.5 Volts DC at the input of the regulator, but only about 10 Volts at the output of the Regulator. What might be the problem? 207) You are troubleshooting an output driver that uses an MPS-A12 (NPN Darlington, 20 V, 0.5 Amp max IC, gain of 5,000 at IC of 10 mA). It drives an Infrared LED from a CMOS circuit. The CMOS circuit is outputting a High (+5 Volts). The Base of the MPS-A12 (an NPN) reads 1.2 Volts. The Emitter is at ground. The LED connects to +5 Volts through a ballast resistor of 180 Ohms. Is this good? Should the LED be on if all things otherwise are well? 208) You are troubleshooting a circuit with a P-Channel MOSFET transistor. The Gate is close to ground. The Drain is connected to +12 Volts. The Source is connected to ground through a resistor and is the output. What should the output voltage be? 209) Which transistor case is larger, TO-92 or TO-220? 210) Which transistor case is larger, TO-92 or SOT-23? 211) Which transistor case is larger, SOT-23 or SOT-223? 212) Which transistor case is larger, TO-92 or TO-5?

213) Which transistor case is larger, SOT-23 or SC-70? 214) Which IC case is larger, DIP-8 or SOIC-16? 215) Which IC case is larger, SOIC-8 or SOT-23-6? 216) Which LED case is 5 mm in diameter? 217) Pins on a DIP IC are how far apart? 218) Pins on a TO-92 case transistor are how far apart? 219) Across a crystal in an oscillator circuit you read 5 V DC and 0 V AC. Is the circuit working properly? 220) You are troubleshooting a circuit with a BS170 (N-Channel MOSFET transistor). On the Gate you find 0 V. On the Source you find 0 Volts. On the Drain you find VCC. Is the transistor good? 221) Which protects a circuit better against spikes on the voltage line, MOVs or Zener Diodes? 222) How wide and long is an 0805 surface mount resistor? 223) What is a likely wattage rating of an 0805 5% SMD resistor? 224) What is a likely wattage rating of a 1206 5% SMD resistor? 225) What is the next larger 5% resistor than a 68 Ohm? 226) When making a substitute for an Electrolytic Capacitor what should you take into consideration? Capacitance, Tolerance on capacitance, Breakdown Voltage, Temperature Range, Case style and size, lead spacing, ESR (in some cases). 227) In 10% values, what is the next larger value to 220? 228) What is an advantage of Polypropylene, Mylar or Film capacitors over Ceramic Capacitors? 229) For general noise filtering what type of ceramic capacitor is cheap but acceptable? C0G, NPO or Z5U

230) A counter is said to have an Asynchronous Clear, what does this mean? 231) A counter is described as being a Synchronous Counter, as opposed to being a Ripple Counter. What does this mean? 232) A power transformer has secondaries of 25 Volts at 4 Amps, 15 Volts at 10 Amps and 125 Volts at 2 Amps. With a 125-Volt primary what is the maximum current you should expect to find in the primary? 233) At what temperature does solder start to melt? 234) At what temperature does Heat Shrink Tubing start to shrink? 235) At what temperature does paper burn? 236) At what temperature does skin burn? 237) At what temperature does water boil? 238) How hot is a hot air gun? 239) How hot is a soldering iron? 240) At what temperature does wire insulation melt? 241) What is considered to be room temperature? 242) What is the freezing point of water? 243) A signal that takes up 4.2 cm vertically at 2 Volts per Division indicates how much voltage? 244) A signal that takes up 5 cm horizontally at 5 µs per division has what frequency?

245) While troubleshooting a circuit you come across a monostable multivibrator with the "Q" output constantly high. Is this an indication of an error? If so, what would you consider the cause? 246) An oscillator is an example of what kind of circuit? Monostable Multivibrator Astable Multivibrator Bi-Stable Multivibrator 247) A J-K Flip Flop is an example of what kind of circuit? Monostable Multivibrator Astable Multivibrator Bi-Stable Multivibrator 248) An single shot is an example of what kind of circuit? Monostable Multivibrator Astable Multivibrator Bi-Stable Multivibrator 249) A Voltage Controlled oscillator is an example of what kind of circuit? Monostable Multivibrator Astable Multivibrator Bi-Stable Multivibrator 250) A D-Type Flip Flop is an example of what kind of circuit? Monostable Multivibrator Astable Multivibrator Bi-Stable Multivibrator 251) On a D-Type Flip Flop with a positive edge triggered clock, if the D and Clock inputs go high at the same time will the Flip Flop Set? 252) On a 74LS74 (D-Type Flip Flop) if the Reset* line is held Low while a High is applied to the D-Input, followed by a Clock pulse, will the Flip Flop end up Set or Clear? 253) On a D-Type Flip Flop are the Data and Clock inputs Synchronous or Asynchronous?

254) On a D-Type Flip Flop are the Preset and Clear inputs Synchronous or Asynchronous? 255) What signals out of the CPU indicate what type of cycle is being done? 256) What signals out of a CPU select the device to wrote to or read from? 257) What signals out of a CPU contain the information being Read or Wrote? 258) If we refer to the CPU as an 8-bit or 16-bit machine, what aspect are we talking about? 259) If we refer to the microprocessor as being a 32 MHz machine, what aspect are we talking about? 260) What is the difference between a RISC CPU and a CISC CPU? 261) What might be an example of a processor with a Harvard Architecture? 262) What might be an example of a processor with a von Neumann Architecture? 263) What processors used in the gaming industry have Memory Mapped I/O? 264) Describe a Memory Write on a Synchronous Bus. 265) Describe a Memory Read on a Synchronous Bus.

266) Describe a Memory Write on an Asynchronous Bus. 267) Describe a Memory Read on an Asynchronous Bus. 268) What is the difference between a microprocessor and a microcontroller? 269) What advantages are there for using a Voltage Reference IC instead of a zener diode?

Identify the following Devices. (Possible answers are available on a following page. Some answers may be used more than once. Some answers may not be used at all.) 270) What is a 74LS00? 271) What is a 74HCT02? 272) What is a 74S04? 273) What is a 7406? 274) What is a 7407? 275) What is a 7408? 276) What is a 7410? 277) What is a 74LS14? 278) What is a 7416? 279) What is a 7417? 280) What is a 7420? 281) What is a 7432? 282) What is a 7447? 283) What is a 74L74? 284) What is a 74LS76? 285) What is a 7483? 286) What is a 7485? 287) What is a 74LS86? 288) What is a 7490? 289) What is a 7492? 290) What is a 7493? 291) What is a 74106?

292) What is a 74107? 293) What is a 74121? 294) What is a 74122? 295) What is a 74123? 296) What is a 74132? 297) What is a 74138? 298) What is a 74139? 299) What is a 74160? 300) What is a 74161? 301) What is a 74162? 302) What is a 74163? 303) What is a 74190? 304) What is a 74191? 305) What is a 74192? 306) What is a 74193? 307) What is a 74221? 308) What is a 74240? 309) What is a 74244? 310) What is a 74245? 311) What is a 74247? 312) What is a 74259? 313) What is a 74266? 314) What is a 74273?

315) What is a 74279? 316) What is a 74373? 317) What is a 74540? 318) What is a 74573? 319) What is a 4001? 320) What is a 4011? 321) What is a 4021? 322) What is a 4094? 323) What is a LM358? 324) What is a MAX232? 325) What is a TDA1175? 326) What is a ULN2003? 327) What is a ULN2803? 328) What is a L298? 329) What is a LM555 330) What is a UC3842? 331) What is a LM324? 332) What is a LF347? 333) What is a LF351? 334) What is a LF353? 335) What is a LM2902? 336) What is a LM2904? 337) What is a LM339?

338) What is a LM319? 339) What is a LM393? 340) What is a LM2901? 341) What is a LM2903? 342) What is a LM7805T? 343) What is a LM7912T? 344) What is a LM3900? 345) What is a TL081? 346) What is a TL082? 347) What is a TL084? 348) What is a LM3302? 349) What is a LM334? 350) What is a LM335? 351) What is a TL431? 352) What is a LM723? 353) What is a LM317? 354) What is a LM337? 355) What is a LM2931? 356) What is a 2N2222? 357) What is a 2N2907? 358) What is a 2N3904? 359) What is a 2N3906? 360) What is a 2N4401?

361) What is a 2N4403? 362) What is a TIP31? 363) What is a TIP102? 364) What is a TIP107? 365) What is a TIP122? 366) What is a TIP120? 367) What is a 1N4001? 368) What is a 1N4002? 369) What is a 1N4003? 370) What is a 1N4004? 371) What is a 1N4005? 372) What is a 1N4006? 373) What is a 1N4007? 374) What is a 1N4148? 375) What is a 1N914? 376) What is a 1N5817? 377) What is a 1N5818? 378) What is a 1N5819? 379) What is a 1N5820? 380) What is a 1N5821? 381) What is a 1N5822? 382) What is a 1N4734? 383) What is a 1N5401?

389) What is a 1N5402? 390) What is a 1N5403? 391) What is a 1N5404? 392) What is a 2N5060? 393) What is a BAS21? 394) What is a BAS70? 395) What is a BZX85C5V6? 396) What is a FR301? 397) What is a HER301? 398) What is a BS170? 399) What is a RXE050? 400) What is a MAX690? 401) What is a TL7705A? 402) What is a ADC0804? 403) What is a LM1408? 404) What is a 2N6427?

Answers for "What is a..." questions. Some answers may not be used. Some answers may be used more than once, but they all should be here. Synchronous Binary Counter with Asynchronous Clear Hex Inverter Synchronous Decade Up / Down Counter Hex buffer, open collector BCD to 7-segment decoder / driver Hex Inverter, Schmitt Trigger Dual D-Type Flip Flop 4-bit Adder Quad 2-input Exclusive-OR Bi-Quinary Counter Quad 2-input AND gate Divide-by-12 Counter 4-bit Binary Counter Dual J-K Flip Flop Triple 3-input NAND gate Dual 4-input NAND gate Hex inverter, open collector Quad 2-input OR gate Retriggerable Monostable Multivibrator Vertical and Horizontal Sync Processor Quad 2-input NAND Schmitt Trigger 3-bit Binary to 1-of-8 Decoder Dual 2-bit Binary to 1-of-4 Decoder Quad 2-input NAND gate Synchronous Decade Counter with Asynchronous Clear Quad 2-input NOR gate Octal Latch, Tri-State Dual J-K Flip Flop Synchronous Binary Up / Down Counter 4-bit Magnitude Comparator Dual Monostable Multivibrator Octal Bi-Directional Buffer BCD to 7-segment Decoder / Driver Octal Programmable Latch Quad 2-input Exclusive-NOR gate Octal Latch Quad S-R Latch Octal Transparent Latch, Tri-State Output Dual Retriggerable Monostable Multivibrator Octal Buffer, Tri-State Quad 2-input NAND gate, CMOS 8-input static shift register 8-output shift and store register

Dual Op Amp Dual RS232 Transceiver, +5 Volt powered Synchronous Decade Up / Down Counter 7-stage Darlington Driver Synchronous Binary Up / Down Counter Quad 2-input NOR gate, CMOS Hex Buffer 8-stage Darlington Driver Half Bridge Motor Driver Timer / Oscillator Switch mode, PWM Regulator Quad Op Amp Quad FET input Op Amp FET input Op Amp Dual FET input Op Amp Quad Op Amp, Low Power Microprocessor Reset / Watchdog / Battery Controller Dual Op Amp, Low Power Quad Voltage Comparator 8-bit Analog to Digital Converter Dual Voltage Comparator Quad Voltage Comparator Voltage Regulator, +5 Volt, 1 Amp Octal Latch, Tri-State Voltage Regulator, -12 V, 1 Amp Quad Norton Amplifier Synchronous Binary Counter with Synchronous Clear Quad FET input Op Amp Adjustable Current Source Temperature Sensor Voltage Reference Adjustable Voltage Regulator Voltage Regulator, +V, adjustable Voltage Regulator, -V, adjustable Low Drop Out Voltage Regulator Transistor, NPN, low power Transistor, PNP, low power Transistor, Power, NPN Transistor, Power, PNP Rectifier, Silicon, 1 A, 50 V Rectifier, Silicon, 1 A, 100 V Rectifier, Silicon, 1 A, 200 V Rectifier, Silicon, 1 A, 400 V Synchronous Decade Counter with Synchronous Clear Rectifier, Silicon, 1 A, 600 V Rectifier, Silicon, 1 A, 800 V

Rectifier, Silicon, 1 A, 1000 V Signal Diode, Silicon Rectifier, Schottky, 20 V, 1 A Rectifier, Schottky, 30 V, 1 A 8-bit Digital to Analog Converter Rectifier, Schottky, 40 V, 1 A Rectifier, Schottky, 20 V, 3 A Microprocessor Reset Supervisor Rectifier, Schottky, 30 V, 3 A Rectifier, Schottky, 40 V, 3 A Zener Diode, 5.6 V, 1 W Rectifier, Silicon, 50 V, 3 Amp Transistor, NPN, TO-92, Darlington Rectifier, Silicon, 100 V, 3 Amp Rectifier, Silicon, 200 V, 3 Amp Rectifier, Silicon, 400 V, 3 Amp SCR, TO-92, 25 V, 0.8 A Signal Diode, SOT-23 Schottky Diode, SOT-23 Zener Diode, 5.6 V, 1 W Fast Recovery Rectifier High Efficiency Rectifier Transistor, N-MOSFET, TO-92 Poly Fuse, 0.50 A Bench Tech test questions Some questions have more than one correct answer. You get one point for each correct answer. No points are taken off for incorrect answers. Some answers require discussion. No points are taken off for spelling or grammer. Points are given for correctness and completeness. 1 You have a power supply that puts out + 5 Volts at 10 Amps, +12 Volts at 5 Amps and -12 Volts at 1 Amp. The circuit driven will be logic circuits. Which fuse should the power supply use? A. 1 Amp, Fast Blow B. 1 Amp Slow Blow C. 2 Amp Fast Blow D. 2 Amp Slow Blow 2. Are switching regulators more prone to failure when AC line voltage sags, or surges? A. Sags

B. Surges C. Both D. Neither 3. Are linear regulators more prone to failure when AC line voltage sags, or surges? A. Sags B. Surges C. Both D. Neither 4. What advantage do MOVs have over Zeners in overvoltage protection? A. Will handle a higher voltage surge B. Will handle faster voltage surges C. Will handle higher currents D. Cheaper 5. What advantage do Zeners have over MOVs in overvoltage protection? A. Will handle a higher voltage surge B. Will handle faster voltage surges C. Will handle higher currents D. Cheaper 6. What is the purpose of an AC Line Filter? A. Keep noise on the AC line from getting into the power supply. B. Keep noise the power supply makes from getting onto the AC line. C. Prevent line voltage sags. D. Prevent line voltage surges. 7. Why is there usually an opto isolator in the feedback circuitry of a switching regulator? A. The voltages on the primary are too high for the circuits on the secondary to handle. B. The voltages on the secondary are too high for the primary to handle.

C. The ground in the secondary is not on the same level as the ground in the primary. The optoisolator provides a feedback signal with no electrical contact. 8. Why is the Hot side of the AC line always the one that is fused? 9. Why is the power switch usually placed closer to the AC Line In than the Fuse? 10. Isolation transformers are used when working on switching power supplies to prevent you from getting shocked. (True / False, Discuss Why) 11. How does drawing more current from the secondary of the transformer cause more current to flow in the primary? 12. Why are fast recovery rectifiers used in switching power supplies? 13. Why would we want to check the outputs of a power supply with no load as well as with a load?

14. What types of voltage checks should be made to test the out of a power supply? A. DC voltage, no load. B. DC voltage, with a load. C. AC voltage, no load. D. AC voltage, with a load. 15. What causes the chirping sound in a malfunctioning power supply? 16. What qualities are important when making a substitution on a transistor? 17. What qualities are important when making a substitution of an electrolytic capacitor? 78. What qualities are important when making a substitution of a rectifier? 19. What is the advantage of using a Voltage Level Monitoring circuit instead of just an LED when monitoring the output of a power supply? 20. What type of IC is used in a Voltage Level Monitor? 21. Grounding straps should always be worn when working on electrical equipment. (True / False, Discuss why)

22. What is Power Factor Correction in a power supply? 23. If the output of a transformer is rated at 12 volts at 300 mA, what will the output voltage be at 100 mA? A. 12 Volts. B. Less than 12 Volts. C. More than 12 Volts. D. None. It won't work at less than 300 mA. 24. If the output of a transformer is 12 Volts AC (at 300 mA) how much voltage DC will we get out of it after rectification (full wave bridge) and filtering, under a 10 mA load? A. Close to 12 Volts DC. B. Around 18 Volts DC. C. Around 15 Volts DC. D. None. It won't work at less than 300 mA. 25. If the output of a transformer is 12 Volts AC (at 300 mA) how much voltage DC will we get out of it after rectification (full wave bridge) and filtering, under a 300 mA load? A. Close to 12 Volts DC. B. Around 18 Volts DC. C. Around 15 Volts DC. D. Close to 10 Volts due to loss across the bridge rectifier. 26. A rectifier design with only one diode is which kind? A. Half Wave. B. Full Wave. C. Bridge. D. Won't work. 27. A rectifier design with two diodes and a center-tapped secondary is which kind? A. Half Wave. B. Full Wave.

C. Bridge. D. Won't work. 28. A rectifier design with four diodes in a square is which kind? A. Half Wave. B. Full Wave. C. Bridge. D. Won't work. 29. A zener diode is uaually used in what kind of circuit? A. Half Wave Rectifier. B. Full Wave rectifier. C. Bridge Rectifier. D. Voltage Regulator. 30. How much load current can you regulate with a 5.1 Volt, 250 mW zener diode? A. 250 mw / 5.1 Volts = about 50 mA. B 5.1 Volts / 250 mW = 20 mA C. About 10 mA (one fifth of answer A.) D. About 2 mA (one tenth of answer B.) 31. What would the typical Emitter to Base voltage be on a Darlington transistor? 32. What is the typical DC Gain on a Darlington transistor? 33. What is the distinction between Enhancement Mode and Depletion Mode MOSFET transistors? 34. Which of the following are standard 5% values? A. 22 B. 33 C. 47 D. 56

35. How should Clamp-on Amp meters be connected when testing AC current on an AC line? A. Around the Hot Lead B. Around the Neutral Lead C. Around both the Hot and Neutral Leads D. In series with the load. 36. Ceramic capacitors with temperature characteristics of 5% or less are likely to be what rating? A. COG B. NPO C. X7R D. Z5U 37. Referring to capacitors what does MLC stand for? 38. What does a ferrite bead accomplish? 39. What would be the normal DC resistance of an inductor? 40. Which wire is thicker, 22 AWG or 24 AWG? 41. Which standard is more likely to be used for communication over a long distance? RS-232 or RS-485? 42. A switch with 3 leads is likely to be what kind of switch? A. SPST B. DPST C. SPDT D. DPDT

43. A light bulb that runs on 28 Volts and draws 80 mA should have a resistance you should measure with a meter of 350 Ohms (28 V / 80 mA). (True / False, Why) 44. An AC Line Noise Filter should have what DC resistance between the Hot Line In and the Hot Line Out? 45. An AC Line Noise Filter should have what DC resistance between the Hot Line In and Ground? 46. An AC Line Noise Filter should have what DC resistance between the Hot Line In and the Neutral Line In? 47. What factors should you consider when selecting a filter capacitor for a power supply? 48. A power supply supplies 1 Amp, running from rectified 60 Hz AC. What should the filter capacitor be like? 49. LEDs in Player Panels have what advantages over incandescent lamps? 50. Which of the following op amp input designs has the highest resistance? A. Bipolar Junction Transistors B. Junction FETs C. MOSFETs 51. Is high input resistance of an op amp a desirable thing?

52. You measure an MOV with a resistance of 10 Ohms. Is it good or bad? 53. You are working on a board that has been designed to Lead-Free standards. Do you need to raise or lower the temperature of your soldering iron? A. Raise B. Lower C. No! same temperature 54. You find a part on a board that looks like a ceramic capacitor and has the part number "RXE050". What resistance should it have? 55. Which is a physically larger fuse? "3AG" or "5 mm x 20 mm"? 56. A Fast Blow fuse rated at 1 Amp will hold a current of 2 Ampds for about how long? 57. What is the advantage of metal film resistors over carbon film? 58. What is the difference between an BAS70, BAS70-04 and BAS70-05 diodes? 59. The end of the diode with a band on it is which lead? 60. What is the difference between a 1N4001 and a 1N4004? 61. On an N-Channel Junction FET as the voltage on the gate goes more positive (with reference to the Source) what happens to the resistance between the Source and Drain?

62. If a transistor has a DC Gain (hFE) of 50 at a Collector current of 10 mA what will the gain likely be at 250 mA? 63. On an SCR as the Gate voltage goes positive with respect to the Cathode the Cathode to Anode resistance drops. What happens when the Gate voltage returns to Ground (Cathode voltage)? 64. Which of the following is not a lead on a MOSFET transistor? A. Emitter B. Gate C. Cathode D. Drain 65. Which of the following is not a lead on an NPN transistor? A. Emitter B. Gate C. Cathode D. Drain 66. Which of the following is not a characteristic of an op amp? A. Open Loop Gain B. Current Transfer Ratio C. Input Offset Voltage D. Common Mode Rejection Ratio 67. Which of the following are characteristics of an optoisolator? A. Open Loop Gain B. Current Transfer Ratio C. Power Supply rejection Ratio D. Common Mode Rejection Ratio 68. Which of the following are characteristics of an op amp? A. Open Loop Gain B. Input Offset Voltage C. Power Supply rejection Ratio

D. Common Mode Rejection Ratio 70. What is the characteristic of an op amp to not respond to ground referenced noise? A. PSRR B. CMRR C. CTR D. RRIO 71. What is the characteristic of an op amp not to respond to changes in supply voltage? A. PSRR B. CMRR C. CTR D. RRIO 72. What things should you consider when looking for a substitute for an electrolytic capacitor? 73. What things should you consider when selecting a filter capacitor for a power supply (following a rectifier)? 74. How much voltage and current can you get from an LM7805? 75. How much voltage and current can you get from an LM7912? 76. How much voltage and current can you get from an LM78L15? 77. An LED is rated at 1.6 Volts at 30 mA. What resistor do you need to run it from 12 Volts?

78. In a bipolar junction transistor as base current increases what happens to the Emitter - Collector resistance? 79. In an N-Channel Enhancement Mode MOSFET transistor as Gate voltage increases what happens to the resistance of the channel? 80. As current through a forward biased diode increases what happens to the diodes resistance? 81. A power supply puts out 12 Volts and is rated at 6 Amps. What load resistor would you use if you wanted to test it under full load? 82. On a Voltage Comparator the Inverting input has 1.2 Volts applied to it and the Non-Inverting input has 1.4 Volts applied to it. What should the output be? 83. Which case is smaller, SOT-23 or SC-70? 84. Which case is smaller, TO-92 or TO-220? 85. Which of the following is not a lead on an SCR? A. Emitter B. Gate C. Cathode D. Drain (050504)