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238 Cards in this Set
- Front
- Back
- 3rd side (hint)
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How do you convert BCD to decimal? |
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How do you convert decimal to binary? |
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What can BCD be converted to? |
Only to decimal. |
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How do you convert binary to BCD? |
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If driven is larger than driver, what does that mean? |
Less speed, more torque. |
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If you only have one belt, should you use a pulley with two shivs? |
No. |
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What does a dashed line represent in a mechanical drawing? |
Indicate concealed edges |
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Dotted and dashed line represents what in a mechanical drawing? |
Used to indicate symmetry about an axis and center locations. |
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Dot dot dash lines in mechanical drawings? |
Used to indicate alternate position. |
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How do you calculate total inductance if there is mutual inductance involved? |
Lt=L1+L2+/- 2k√L1L2 |
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When inductors are in series, how do you find total inductance? |
Lt=L1+L2 |
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How do you find total inductance when adding in parallel? |
1/Lt = 1/L1 + 1/L2 + 1/L3 |
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What are these? What sort of cores do they have? |
Transformers. First has air core, second has ferrite core, third has iron core. |
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Label these |
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Label these |
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What's the equation for power dissipation? |
P=E^2/R |
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Look over these. |
Good job! |
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What unit is power in in the US? |
Horsepower |
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What unit is power in in standard? |
Kilowatts |
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What unit is torque in us? |
Ftlbs |
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What unit is torque in Standard? |
Newton meters. |
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What unit is speed in US? |
RPM |
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What unit is speed in Standard? |
RPM |
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How do you calculate horsepower? |
Power = (torque X speed)/5252 |
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How do you calculate kilowatts? |
Power = (torque X speed)/9549 |
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How do you convert HP to Kw? |
Multiply answer by .746 |
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How do you convert Kw to HP? |
Divide answer by . 746 |
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What do phase to ground measurements on a wye motor measure? |
Phase to phase voltage/1.73 |
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What sort of motor configuration is this? |
Wye. |
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1/frequency equals what? |
Time |
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What does RMS mean? |
Root mean squared |
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What is RMS value? |
. 707volts |
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What is AVG waveform value? |
.637volts |
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Fill in the blanks. |
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What does 0 represent in digital? |
Low. Zero volts. |
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What's a low in digital? |
0. 0volts. |
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What's a 1 in digital? |
High. 5v. |
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What's a high in digital? |
1. 5v. |
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What will a disconnected or floating input read? |
High. |
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What's fan out? |
The number of inputs that can be driven by one output. |
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What does LED stand for? |
Light emitting diode. |
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Does an LED have polarity? |
Yes. |
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What should you always place in front of an LED? |
A 330 ohm resistor. |
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What are pull up resistors used for? |
To verify the voltage is at 5v. |
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What resistance are the pull up resistors we use? |
10kohm |
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What's the symbol for an LED? |
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Should anode or cathode be more positive? |
Anode should be more positive. |
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Should anode or cathode be more negative? |
Cathode should be more negative. |
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Which side of the LED symbol is the cathode? |
The side with the line. |
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How do you tell which side of a physical LED is the anode or a cathode? |
The anode leg is longer. The cathode leg is shorter. The cathode side has a flat spot. |
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What's the fan out here? |
Three. |
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What's this? |
An and gate |
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What's this? |
An or gate |
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What's this? |
A not gate. |
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What's this? |
A nand gate |
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What's this? |
A nor gate |
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What's this? |
An XOR gate |
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What's this? |
An XNOR gate |
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What's this? |
And gate |
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What's this? |
Or gate |
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What's this? |
Not gate |
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What's this? |
Nand gate |
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What's this? |
A nor gate. |
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What's this? |
An xor gate |
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What's this? |
An XNOR gate |
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What's a positive pulse? |
A pulse that goes from one voltage level to a more positive level and then returns. |
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What's a negative pulse? |
A pulse that goes from one voltage level to a more negative level and then returns. |
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Does a pulse have to transition from zero volts? |
No. Can transition from 5v to -5v |
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What duty cycle does a symmetrical pulse have? |
50% |
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What sort of wave does a symmetrical pulse make? |
A perfect square wave. |
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What does a non-symmetrical pulse have? |
A duty cycle that isn't 50% |
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What's a periodic pulse? What else does it have? |
A signal which repeats is waveform after a fixed period of time. A specific frequency or period. |
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What's a non-periodic pulse? Does it have a specific frequency or period? What does it arrive at? |
Doesn't repeat its waveform in a fixed period of time. Doesn't have a specific frequency or period. Arrives at irregular intervals. |
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What is common for data and digital communications? |
Non-periodic pulses. |
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Label please |
A: Trailing edge B: Pulse interval C: Leading edge D: Pulse width E: Pulse repetition time
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What's a trailing edge? |
The portion of the pulse that returns to a normal value. Positive to less positive. |
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What's a pulse interval? |
The amount of time that the pulse is inactive. Time between trailing edge and leading edge. |
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What's the leading edge? |
Portion of a pulse that goes from one voltage level to a more positive level. |
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What's pulse width also known as? 2 |
Pulse time or pulse duration. |
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What's pulse width? |
Amount of time the pulse is active |
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What is pulse repetition also known as? |
PRT. |
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What is pulse repetition time? |
The period of the pulse. Time it takes for one cycle. |
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What's the equation for pulse repetition time? |
Pulse interval plus pulse width equals pulse repetition time. |
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What is pulse repetition rate? |
The frequency. |
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What is frequency in relation to pulse? |
Pulse repetition rate. Number of cycles per second. |
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What's the equation for duty cycle? |
Pulse width divided by pulse repetition time. |
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What is duty cycle expressed as? |
A percent. |
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What is duty cycle? |
The amount of time a signal is on. |
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Label |
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What is rise time? |
The amount of time it takes for a pulse to rise from 10% to 90% of its maximum value. |
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What is fall time? |
The amount of time it takes for a pulse to drop from 90% to 10% of its maximum value. |
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What's an edge trigger? |
The output only changes at the edge of a clock pulse. |
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What's an active high/active low? |
Either a high or a low must be present to enable/turn on the output. |
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What's a pulse trigger? |
High and low of a clock pulse is needed to change the Q outputs according to the SR condition. |
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On a 480v Delta motor, what's phase to phase voltage? |
480v |
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On a 480v Delta motor, what's the phase to ground voltage on all the legs except the wild leg? |
240v (half of source voltage) |
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On a 480v Delta motor, what's the phase to ground voltage on the wild leg? |
415v |
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What's the equation for inductive reactance on a Delta motor? |
(2) (pi) (f) (l) |
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What's the equation for capacitive reactance on a Delta motor? |
1/((2) (pi) (f) (l)) |
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How is a triac formed? |
With two SCRs are joined in parallel. |
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What does triac stand for? |
Triode AC switch |
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What is a Triac commonly used for? |
Simple, low power applications. (household dimmer switches, fans, small motors, General AC control) |
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What's the difference between a triac and an SCR? |
SCRs are more flexible to be used in high power control circuits because they can be controlled more easily. Triacs are for simple low power applications. |
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What's a triac symbol look like? |
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Does a triac have an anode and a cathode? |
No. |
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What does a triac equivalent circuit look like? |
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What does MT stand for in relation to triacs? |
Main terminal |
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Are MT1 and MT2 interchangeable in triacs? |
No. |
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Which main terminal should the gate receive its triggering current from on a triac? |
MT2 |
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What is an SCR? (in relation to current?) |
It's a unidirectional (one way) current device. |
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How much of the AC waveform does an SCR pass? |
180°. |
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What are triacs in relation to current? |
Bidirectional (two way) |
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How much of the AC waveform do triacs pass? |
360°. Full waveform. |
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Label |
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Is triac triggering symmetrical? |
No. |
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Because triac triggering isn't symmetrical, what has to happen with high power loads? |
Two individual SCRs are used to control high power loads. |
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Why are two SCRs used instead of triacs on high power loads? |
Because SCRs can control their gates individually, which provides more flexibility. |
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Can triacs control their gates individually? |
No |
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Can SCRs control their gates individually? |
Yes. |
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What's a diac? |
A diode that conducts current only after its breakover voltage has been reached momentarily. |
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What's a diac's breakover voltage? |
30v |
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What does DIAC stand for? |
Diode for alternating current. |
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Does a diac have a gate? |
No. |
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How is a diac used? In reference to a triac |
In series with the gate on a TRIAC to help it fire more symmetrically. |
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What's the symbol for a DIAC? |
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How do you use a meter to test a TRIAC? |
Set meter to diode test, use meter leads to test mt1, mt2, or gate to each other. |
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What should the meter read when testing a TRIAC? |
Pos Mt1 to neg mt2 should read a high resistance, neg mt1 to pos mt2 should read low resistance. |
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What logic gate can function as any other logic gate? |
NAND |
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What's this equivalent to? |
A NAND |
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What are the graphite connectors that ride against the motor commutator called? |
Brushes. |
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What are the two ways to connect coils in an armature? |
Lap windings and wave windings |
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Experimentally, the torque of a motor is measured directly by a device called what? |
Prony break |
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What starting torque do repulsion Motors have? |
High |
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Split phase motors have how many separate windings? |
2. |
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Induction Motors are classified by what? |
Motor size. |
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What isn't part of a resistance-start induction-run motor? |
Brushes |
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To reverse rotation on a single phase capacitor start motor, what do you do? |
Reverse the leads on the start winding. |
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The AC wave form is called a what? |
A sin wave |
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Eddy current and hysteresis losses are losses in what? |
Magnetic core. |
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What's this? |
A flow switch |
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What are robot controllers used as? |
Microprocessor controllers. |
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Is this timed to open or closed? |
Open |
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What does this diagram show? |
A DC shunt motor starter. |
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Sticking in a relay is caused by what? |
Residual magnetism or spring action. |
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Pick up value of a relay is what in relation to the drop out value? |
Higher than the drop out value |
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What type of DC motor will eventually destroy itself with high speed and no mechanical load? |
A series wound motor. |
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Conventional method of changing the direction of rotation in DC series wound motor is what? |
Reversing the armature winding |
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What's this? |
A differential synchro system |
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Why may an AC induction motor fail to start? |
Open armature winding |
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A split phase induction motor does what? |
Uses starting and running windings wound with different resistance and reactance. |
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Synchronous speed equation? |
(120 • f)/p |
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Which side of the LED symbol is negative? (not anode or cathode) |
The side with the line. |
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What doesn't affect voltage drop? |
Conductor current |
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What does SCR stand for? |
Silicon controlled rectifier. |
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What category does an SCR go in? |
Thyristor category. |
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What is an SCR? |
A semiconductor that allows control of current using a small current. |
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What operates sort if like a transistor? |
An SCR. |
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What sort of regions is an SCR made up of? |
N and P regions sandwiched on top of each other. |
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What is an SCR? |
A rectifier. |
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What dies a rectifier circuit do? |
Only conducts 180°. Not AC. |
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What does the SCR act like? (not transistor) |
A very fast switch. |
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How do you operate an SCR? |
Cathode to neg, Anode to load, Current from anode to gate. When current is applied to gate, current flows through SCR and load is on. Current is removed from gate, SCR still conducts. To stop current flow through SCR, current must be stopped on anode or cathode. |
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With SCRs, when is the load on? |
After power has been applied to the gate. |
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How do you turn off an SCR that has been turned on? |
Remove power to anode or cathode. |
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If current is removed from gate, will the SCR still conduct? |
Yes. |
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What's this? |
An SCR. |
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What is holding current? (SCR) |
The amount of current needed to keep the SCR latched on. |
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What does bi-stable device mean? |
Either on or off. |
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Is the SCR a bi-stable device? |
Yes. |
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Is an SCR easy to troubleshoot? |
Yes. |
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When troubleshooting an SCR, what might the problem be? |
Load or SCR |
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If the SCR fails to latch, could the problem be with the load? |
Yes. It needs a holding current. |
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What are internal resistors used for on SCRs? |
To prevent false triggering. |
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What are most applications of an SCR for? |
AC power control. Why? |
Because an SCR can handle large currents and can be triggered to turn on at different phase angles. |
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Can an SCR handle large currents? |
Yes |
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Can an SCR be triggered to turn on at different phase angles? |
Yes. |
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When will an SCR turn itself off in a circuit? AC |
When the AC power reverses polarity. |
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Will an SCR turn itself off in a DC circuit? |
No. |
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Will an SCR turn itself off in an AC circuit? |
Yes. |
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Look at this |
Good job! |
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Are transistors solid state devices? |
Yes. |
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What is a transistor? |
A semiconductor that can do two jobs. |
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What are the jobs that a transistor can do? |
Amplifier and switch. |
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As an amplifier, what does a transistor do? |
Amplifies current in proportion to input signal. |
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What's an example of a transistor acting as an amplifier? |
.1a on input switch gets 1a on output. |
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What are transistors used for when used as a switch? (3) |
Faster switching, No contact bounce, No voltage spike. |
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Transistor used as amplifier takes and produces what? |
Small current in one end and produces large current on other end. |
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Transistors as a switch allows what? |
Small current to conduct a larger current. |
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What is a transistor switch kind of like? |
Relay. |
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How many pins does a transistor have? |
Three. |
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What are the three pins on a transistor? |
Collecter, base (middle pin), and emitter (pin closest to tab). |
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What are the types of transistors? |
NPN and PNP. |
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How do you tell NPN and PNP transistors apart? |
PNP has arrow pointing in, NPN has arrow pointing out. (not pointing in) |
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What is the arrow always on on a transistor? |
On the emitter. |
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Does n type or p type material have more free electrons? What about holes? (positively charged electrons?) |
N has more negatively charged particles, P has more positively charged particles. |
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What type of material are transistors made of? |
N and P material stacked on top of each other. |
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Are the regions equal size on transistors? |
No. |
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What's the largest region on a transistor? |
The collector. |
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What is doping? |
Region having different amount of positive or negatively charged particles. |
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Are the emitter and the base of the transistor forward or reverse biased? |
Forward. |
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How does a phototransistor work? |
Like a normal transistor, except vase current is controlled by amount of visible infrared light. |
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How many pins does a phototransistor have? |
Two. |
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More light and less light means what for a phototransistor? |
More light means more current, less light means less current. |
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What's an optoisolators? |
A component that transfers electrical signal between two isolated circuits by using light. |
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Optoisolators prevent what? |
Prevent high voltages from affecting the system receiving the signal. |
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If collected and emitter of a phototransistor get switched around with no other change, what happens? |
Transistor blows. |
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What's a rectifier? |
An electrical circuit made up of diodes that convert AC to DC |
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What do diodes do? |
Only allow current to flow one way. |
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How does a diode affect AC? |
It only allows half the waveform through. |
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What are the types of rectifiers? |
Half wave, Full wave, And full wave bridge. |
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How many diodes does a half wave rectifier use? |
One. |
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How much of the AC waveform does a half wave rectifier pass? (pos/neg) |
Positive only. |
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Is half wave rectifier efficient? |
No. Wastes half waveform. |
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How many diodes does a full wave rectifier use? |
Two. |
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How many diodes does a full wave rectifier use at one time? |
One at a time. |
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What expensive thing does a full wave rectifier use? What don't you get? |
Transformer. You don't get full voltage. |
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How many diodes does a full wave bridge rectifier use? |
Four. |
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How many diodes conduct at a time in a full wave bridge rectifier? |
Two. |
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Does a full wave bridge rectifier use a center tapped transformer? |
No. |
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What's the output on a full wave bridge rectifier? |
Pulsating dc |
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What do filters do? |
Convert pulsating DC to unvarying DC voltage. |
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How do filters work? |
Using a capacitor. |
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What do capacitive filters do? |
Use a capacitor in parallel to the load resistor to suppress ripple currents while not affecting DC currents. |
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Larger capacitor in filter means what? |
Less ripple. |
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Look at these |
Good job |
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What's a diode? |
A semiconductor that only allows current in one direction. |
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Does a diode act like a conductor or an insulator? |
Both at different times. |
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What are diodes usually made from? |
Silicon. |
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How many terminals does a diode have? |
Two. |
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What are the three main purposes of diodes? |
Isolation, arc suppression, rectification. |
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What two types of material are diodes made of? |
N and P type. |
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Silicone diodes drop how much voltage while conducting? |
.7 to 1.1 volts. |
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How much voltage do LEDs drop? |
1-2.5 volts |
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On a diode, what does the stripe mark? |
The cathode. |
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What happens to like charges? |
The repel each other. |
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What can be used for arc suppression? |
Diodes. |
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How do you use a diode for arc suppression? |
Put it in parallel with the load. |
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What's the smallest region on a transistor? |
The base. |
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