Circuit Electronics

When electric current is flowing in a circuit, if the voltage applied to the circuit is increased,
A. the resistance will increase.
B. the current will increase.
C. the resistance will decrease.
D. the current will decrease.

2. Which of the following information sources will not be directly affected by the Telecommunications Act of 1996?
A. Telephone services
B. The Internet
C. Newspaper publishing
D. Cable television

3. Porcelain, paper, glass, and rubber are all examples of electrical
A. conductors.
B. batteries.
C. insulators.
D. grounds.

4. A testing instrument that an electronics technician will connect to selected points inside a piece of electronic equipment and measure electrical values such as ohms, volts, and amperes is called
A. a signal generator.
B. a power supply.
C. an oscilloscope.
D. a multimeter.

FIGURE A-1—Use this illustration to answer Question 5.

5. Look at the four schematic symbols shown in Figure A-1. Each of the symbols is labeled with a number. Which of the following statements about these symbols is correct?
A. Symbol 1 represents a diode, symbol 2 represents a resistor, symbol 3 represents an LED, and symbol 4 represents a transistor.
B. Symbol 1 represents a diode, symbol 2 represents an LED, symbol 3 represents a transistor, and symbol 4 represents a resistor.
C. Symbol 1 represents a transistor, symbol 2 represents a resistor, symbol 3 represents an LED, and symbol 4 represents a diode.
D. Symbol 1 represents a transistor, symbol 2 represents a diode, symbol 3 represents a resistor, and symbol 4 represents an LED.

6. Which of the following is a correct definition of the term rectification?
A. Rectification is the opposition to current flow in a circuit.
B. Rectification involves sensing an electrical quantity and converting it to a signal.
C. Rectification is the conversion of AC current to DC current.
D. Rectification refers to the connection of components into a circuit.

FIGURE A-2—Use this illustration to answer
Questions 7–10.

7. Look at the simple circuit illustrated in Figure A-2. What will happen when only switch S1 is closed?
A. The light bulb will light up.
B. Current will flow in the circuit.
C. The resistance of the circuit will increase.
D. Nothing will happen—the light bulb won’t light up.

8. In the circuit shown in Figure A-2, what will happen when switches S1 and S3 are both closed?
A. The light bulb will light up.
B. Current will flow in the circuit.
C. The resistance of the circuit will increase.
D. Nothing will happen—the light bulb won’t light up.

9. In the circuit shown in Figure A-2, what will happen when switches S2 and S3 are both closed?
A. The light bulb will light up.
B. Current will flow in the circuit.
C. The resistance of the circuit will increase.
D. Nothing will happen—the light bulb won’t light up.

10. In the circuit shown in Figure A-2, which switches must be closed in order for the light bulb to light up?
A. Only switch S1 needs to be closed in order for the light bulb to light up.
B. Only switches S1 and S2 need to be closed in order for the light bulb to light up.
C. Only switches S1 and S3 need to be closed in order for the light bulb to light up.
D. Only switches S2 and S3 need to be closed in order for the light bulb to light up.

11. At a job interview, the most effective way to prove your proficiency to a prospective employer is to show that you have
A. membership in several professional organizations.
B. certification as an electronics technician.
C. experience with on-line research.
D. your own test equipment.

12. Which one of the following letters is used as an abbreviation when representing a unit of electric current?
A. E
B. R
C. C
D. A

FIGURE A-3—Use this illustration to answer Question 13.

13. Safety is a concern around electronic equipment of all types. When you see the sign and the symbol shown in Figure A-3, what particular safety hazard may exist?
A. High voltage
B. Laser light
C. Delicate equipment
D. Radioactivity

14. Which of the following statements about light-emitting diodes is correct?
A. Light-emitting diodes conduct current in either direction in circuits.
B. Light-emitting diodes are used as indicators in circuits.
C. Light-emitting diodes have very short life-spans in circuits.
D. Light-emitting diodes are used as rectifiers in circuits.

15. On a printed circuit board, electronic components will be mounted
A. from the substrate side of the board.
B. from the side of the board that contains the conducting paths.

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XXX-XXX-XXXX
Education Penn Foster
Scranton, PA 18515-0001
Electrician program in progress

Seneca College of Applied Arts and Technology
Scarborough, Ontario
Major: Industrial Maintenance Mechanic Electricity and Electronic

College of Arts Science and Technology
Kingston, Jamaica
Major: Mechanical Engineer Technician

Related Work 1998-2010
Prestige Window Fashions
195 Raritan Center Parkway, Edison, New Jersey
Worked as an Industrial Maintenance Mechanic. I performed electrical installation and repaired on the building and machineries. Trouble shooting and repairs blind making machines such as, Sani, Faber, Turnils, and Hunter Douglas high speed strapping machines, sewing machine, automation machines and drill presses. Dismantled, rebuilt and installed high speed production machines, electric motors, compressors, pumps, pneumatic and hydraulic presses and compacters. Designed and built replacements parts for specialty tools and machines. Conducted milling, lathing, boring, welding (gas, arc, mig, tig) and soldering. Set up maintenance program to minimizing production down time. Performed wiring and installation of electrical circuits and panels, receptacles, switches, boxes, conducts, cable assemblies and lighting fixtures. Repair and performed preventatives Maintenance on machines and equipments. Work from blueprints schematics and work drawings. Ensure that machines removed for repairs work are done to specifications and within time and budget. Make request for purchases of parts for repairs and services of machines as needed.

1994-1998
Otema Interior Fixtures
Markham, Ontario
Employed as an Industrial Maintenance Mechanic. Trouble shoot and repair faulty electrical and mechanical equipment. Rebuilt pneumatic and hydraulic equipment compressors, pumps, motors. Operate milling, boring and lathe machines. Perform welding (gas, arc, mig and tig) and soldering. Repair glass cutting machine , table saws ,drill presses, dust collectors, and bending machines. Work from working, drawing, blueprint, schematics. Perform layout and fabrication of metal doors, rails and metal furniture’s. Order parts for machine repairs as needed.

Honor Seneca College Honor graduate

Achievement Prestige Window Fashion Employee of the Year

References References are available on request.

Have you read the latest… it seems that there is a small possibility that Cosmic rays from outer space that penetrate through the Earth’s atmosphere, may be a contributing factor to the unintended acceleration problem in Toyota cars. Even though they are called rays, they are actually single particles travelling close to the speed of light, and strike the earth’s surface rarely but in a random fashion. Harmless to humans in low quantities, but cause problems in microprocessors and memory chips. How likely is it that cosmic rays are the problem? Could this phenomenon be connected to the brake problem also, or was this purely code?

How about some of these other possible reasons for random electronic problems that I’ve thought of__:

–> The introduction of RoHS (Removal of Hazardous Substances) has brought about lead-free solder. What if the absence of lead has meant electronic systems are now more susceptible to certain forms of interference?

–> Maybe the automotive Hardware and Software engineers "can’t see the wood for the trees". i.e. they are all so focused on certain elements of design, that there is nobody to stand back and look at the big picture. What if the solution to Toyota’s problems turns out to be something known and practiced 20 years ago…

–> Coming back to the Cosmic Ray theory… Maybe, (just maybe!), there are stray particles coming from the numerous Particle Accelerator Experiments around the globe. Maybe some are not buried deep enough underground, and during the collisions the scientists are creating particles that escape, particles that we can’t even understand or detect yet!! The physicists even admit themselves that they do not know what to expect in the quest to uncover Higgs.

–> Cars are fast becoming computers on wheels… A few weeks ago, when turning on my mobile phone, the crossover burst of RF from the phone unlocked the remote control central locking in my Japanese manufactured car. Security is one thing, but safety is another. Is it possible that modern-day electronic gadgets (Quad band Blackberry phones, a faulty pacemaker, Bluetooth car kits…) are playing a part in the issue, and Toyota have stumbled across it first as they are more advanced with their electronic Engine Management Systems?

–> Rogue fragments of metal sliding around the PCB. Circuit boards are cleaned after the components are mounted, but what if minute metal shards escape onto the board afterwards during ICT testing, in-house repair or final assembly (you may not see it, but even tightening a brass screw scrapes tiny bits of metal off the brittle surface, and with the BGA balls so close to each other these days….)

–> Is somebody playing around with a military spec electromagnetic pulse, or has electronics gone as far as it can reliably go for now? ICs have become so compact, that maybe the circuits need to have a protective mini-bubble around them!

How many other manufacturers will follow Toyota, and have similar issues?

Until they know what’s going on, and as a temporary proactive safety solution, maybe all new cars should be fitted with a big red ‘panic’ button on the dash. This old fashioned mechanical switch would instantly kill the drive-by-wire electronics and/or the fuel, but leave the brakes still operating. At the moment, it looks like people are panicking and forgetting the safety procedure during the power surge.

Any ideas, can NASA save the day?!?

Hi all. I am trying to repair an old Casio keyboard. I have found the problem component on the power circuit marked A934 QH. I believe it to be a voltage regulator, however I am unable to find any information as to its electrical characteristics. Does anyone have any information as to its specifications or know of a compatible replacement? Thanks in advance for any help on this issue.

***********************************
420*******************************, Alexandria, Egypt, +(20)-03
Tel: ****************** Mobile: ********************
Email: *******************@yahoo.com
Education
Electrical engineering-communications session
Faculty of engineering 2006
GPA fair (60.9 %(
Graduation project topic: Ultrasound and Microwave hyperthermia
Participation:
Ultrasound transducer theoretical issues:
Piezoelectricity
Ultrasound transducers
Characteristics of transducers
Resonance
Pulse echo methods
Practical part:
Implementation of an US transceiver circuit.
It was an alarm system in miniature, based upon transmitting and receiving of ultrasound rays.
Personal contributions:
Voluntarily handled some of my colleagues’ problems helping them to avoid side quarrels. Shared my own ideas with others trying not to be selfish.
Grade very good

Work Experience: an unpaid intern who was keen to add as much practical experience as possible
#SPECIALISED MEDICAL TEST EQUIPMENT
for troubleshooting with American Instructor –
- Understanding medical repairing
* Electronics Troubleshooting
** X-ray machine, Ultrasound, ECG – Lasers machine
1 – Troubleshooting medical equipments & electronic PCBs in Maintenance Center
2- practical Training with American Instructor
3 – Practical Training with professional engineers – repairing medical equipments
- practical training in medical centers & big medical companies in Cairo
#Electronics Troubleshooting,Problem Identification & Repair
Testing all Electronic Components in board & out board Practical
- Understand The Secrets Of Electronic Components
- Understand it using the datasheet
- Understand the Advanced Technique in Troubleshooting & Repairing
- understand the common errors in electronic components
- SMD Components troubleshooting
- Appreciate the safety precautions when troubleshooting electronic equipment.
- How to get a replacement for semiconductor
- Understand semiconductor codes
- Components that break down under full load
- Comprehend semiconductor substitution manual book.
- Build 5 Electronic Testers
- Build your electronic testers & save money NEW
- Understand TTL , CMOS & DTL Families
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- understand the secrets of ICs
- Using the programmer in Electronic Troubleshooting & Repairing
Using our electronic Testers & Equipments
Oscilloscope & Function Generator Tutorial
• Appreciate the safety precautions when troubleshooting electronic equipment.
• Understanding all electronic components & testing it
• Understand SMD Components & Testing it
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• Utilize a multimeter analoge & digital
• Utilize a Blue esr meter , Blue ring tester , peak equipments , semiconductor analyzer & identification, IC tester, Semiconductor Identifier, Logic Probe,Osilloscope,…………….
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- Understanding SMD book ( pdf format ) CD
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Cross reference ( SMD )- Transistor – JFET – Mosfet – Diode ( pdf format ) CD

Programming Embedded PIC Microcontrollers
Course content
1-What is the microcontroller?
2-Features of BASIC language and its FUNCTIONS
3-I/Oput and shifting operations with several examples.
4-interfacing with display devises (lcd –seven segments) with examples.
5-Debounce troubleshooting.
6-Timers(timer 0 ,timer 1), portB change interrupt and hardware interrupt with examples.
7-Analog to digital conversion and digital to analog conversion with examples.
8-PWM (pulse width modulation) and the Keypad with examples.
9-Universal synchronous asynchronous serial communication (RS232) .
10- EEPROM memory with examples.
11- I2C protocol and interfacing with the external memory with examples .
12-Sound with PIC with examples
13-Flying to program with C language using MikroC .
- Basics of C language .
- LCD Interfacing .
- Serial communications with examples .
- Keypad and 7 Segment Interfacing with examples.
- ADC with examples.
- Interrupts(timer0 and timer1) .
- Mixing assembly and C languages.
14- EXCITING PROJECTS WITH PIC :
DO IT YOURSELF
-Security system based on the keypad .
-DC MOTOR CONTROL.
-Sony remote control decoding and controlling .
-STEPPER MOTOR CONTROL

I have to cut a hanger loop (about three eights of an inch oval shaped, with a thickness like a #8 guage wire) open and attach it to another bauble. The whole mess is worth about 0. With no knowledge of jewelry repairs, including what supplies I need, would it be wiser to take it to a jeweler, or can I buy what I need, and do the job myself with less expense?

I went to radio shack and purchased all the components I need for a circuit. Except a 4.7pF capacitor. It doesn’t have to be exactly 4.7, it said around 4.7pF. I don’t really want to buy 1 dollars worth of something online. Does anyone know what kind of electronic device I could find one in? And how to read the value, or a link to read the value. Also where could i find a small trimmer capacitor, or variable capacitor? What devices, Thanks, Tim

1. If the current through a heater coil is 5 amp and the supply voltage is 120 volts, the coil resistance is
A. 0.04 ohm.
B. 24 ohms.
C. 110 ohms.
D. 575 ohms.

2. The amount of current flowing in a circuit can be measured by
A. an ammeter.
B. a voltmeter.
C. a neon test lamp.
D. an ohmmeter.

3. Which one of the following letters is used in formulas as the symbol for voltage?
A. P
B. W
C. I
D. E

4. The conductors in electrical devices are commonly made of
A. iron.
B. nickel.
C. copper.
D. lead.

5. The energy used by an appliance which operates at 240 volts at 15 amp for 4 hr. is
A. 0.92 kwhr.
B. 3.45 kwhr.
C. 14.4 kwhr.
D. 60.0 kwhr.

6. What is the voltage in a circuit with a resistance of 12 ohms and a current of 20 amp?
A. 0.58 volt
B. 1.74 volts
C. 120 volts
D. 240 volts

7. If an appliance does NOT work at all when you plug it in and turn the switch on, the appliance circuit is
A. shorted.
B. overloaded.
C. leaking.
D. open.

8. To read the line voltage supplied to an appliance, you should connect the voltmeter
A. in series with the power supply.
B. between the grounded wire and the water pipe.
C. across the power supply.
D. between terminals of two adjacent circuit parts.

9. The best method for testing the continuity of each part of an appliance uses
A. a voltmeter.
B. an ammeter.
C. an ohmmeter.
D. a wattmeter.

10. A 2000-watt heater connected to a 120-volt circuit will draw a current of
A. 5.75 amp.
B. 15 amp.
C. 16.67 amp.
D. 23 amp.

11. What type of fault causes an appliance to blow a fuse when the appliance is turned on?
A. An open circuit
B. Too much resistance
C. A short circuit
D. Too high a voltage

12. Which one of the following conditions is unfavorable for the use of an ohmmeter?
A. Voltage is supplied to the appliance
B. The appliance is grounded
C. Moisture is in the insulation
D. The appliance circuit is shorted

13. A series circuit in an appliance consists of
A. several branches carrying independent currents.
B. more than one part connected across the same terminals.
C. several parts connected end to end.
D. more than one path carrying the current.

14. Which one of the following components is used to change an AC voltage to a lower or higher value?
A. Transistor
B. Transformer
C. Capacitor
D. Resistor

15. A full-wave bridge rectifier uses how many diodes?
A. One
B. Two
C. Three
D. Four

16. An NPN transistor is correctly biased and turned on if the
A. base is negative.
B. collector is negative.
C. collector is positive with respect to the emitter and negative with respect to the base.
D. collector is the most positive lead followed by the base.

17. When an SCR turns ON, it acts like a(n)
A. transistor.
B. resistor and capacitor in series.
C. electronic switch and rectifier.
D. bridge rectifier.

18. Which one of the following IC digital gates requires a high on both inputs to output a high?
A. AND
B. OR
C. NAND
D. NOR

19. Which one of the following IC gates will have a low output if either of the inputs are high?
A. Buffer
B. NAND
C. NOR
D. OR

20. A microprocessor runs an internal program called a(n)
A. operating system.
B. scratchpad memory.
C. instruction chain.
D. PAL.

21. A resistor with the color bands brown, red, red and silver will have a resistance of
A. 120 ohms.
B. 1,200 ohms.
C. 2,100 ohms.
D. 6,400 ohms.

22. What type of diagram chart in a service manual can be used to easily service an electronic circuit board with ICs?
A. Exploded
B. Flowchart
C. Assembly
D. Pictorial

23. An LED display device uses how many segments to create the number 8?
A. Three
B. Four
C. Seven
D. Eight

24. When testing transistors, how much minimum voltage difference should be seen across the base-emitter junction?
A. 0.1 VDC
B. 0.4 VDC
C. 0.6 VDC
D. 0.9 VDC

25. When you are forward-bias testing a diode with a digital VOM, the red test lead should be placed on which lead of the diode?
A. Anode
B. Cathode
C. Emitter
D. Drain

I need a special type of circuit, which will give me 200-300 voltage impulses DC, which last 1 or 2 second, with 1-2 second of delay between the impulses… I dont have a signal generator I think i will be able to build one impulse generator with that frequency… I can use a capacitor too, but I’m to lazy to plug out it every time I will need it to discharge it… is there a circuit that will do it automatically???

TV’s radios and power supply circuits are repaired by technicians who hold not degrees in EEE, I feel I am the one who should have the knowledge to do so but unfortunately college does not tech us useful stuff. What is the best approach to gain such knowledge and what resources are available on the internet?