CONST 150 LAB 1 SOLDERING

SOLDERING SAFETY TIPS

• Wear eye protection.• Work in a well-ventilated area.• Do not put wires or solder in your mouth.• Wash your hands when you are finished.

BASIC REQUIREMENTS• Clean metal surfaces• Clean, tinned soldering iron• Correct solder and flux• Correct temperature and time

The actual methods used depend on the toolsand materials at hand, the physical nature of theparts and boards, and the skill of the worker.

Electronic hand soldering is typically accomplished by quickly heating the metal parts to be joined, and then applying flux and solder to the mating surfaces. The flux is often supplied automatically by using wire shaped solder with a hollow core. The flux is usually rosin and is contained within the core. A finished solder joint is a metallurgical bond. Soldering forms an electrical connection between the parts and a mechanical joint. Heat is supplied with a soldering iron or other means. The flux is a chemical cleaner which prepares the hot surfaces for the molten solder by dissolving any oxide films on the metal parts. Also, and perhaps more importantly, the flux coats and prevents the heated base metals from oxidizing. The solder is a low melting point alloy of non ferrous metals. The melting point of most electronic solder is approximately 370 °F and the iron tip temperature is around 650 °F or more.

When an alloy, such as solder, is heated it typically goes thorough three phases. It goes from a solid phase to a plastic phase (halfway between a liquid and a solid) and then to a liquid phase. Eutectic solder is an alloy with no plastic phase. The eutectic alloy is made up of 63% tin and 37% lead. The plastic phase is not desirable because additional heat is required to reach the liquid phase and the additional heat can damage parts and circuit boards. Eutectic tin/lead solder has the lowest possible melting temperature (361 °F).Eutectic solder changes to a liquid just above the melting point and, as it cools, it will transform directly into a solid. This makes it possible to quickly form superior solder joints. A 60% tin and 40% lead alloy can also be used. This alloy shows an almost eutectic change from solid to a liquid and has a melting range of 361 °F to 374 °F.Another alloy is available that uses 62% tin, 36% lead and 2% silver. It has a melting range of 354 °F to 372 °F. It is preferred for surface mount chip components because it prevents silver from leeching from the components into the solder joints.

Common mistakes:1. The metal parts are not clean.2. The solder or the flux is not the correct type.3. The soldering tip is too small for the joint.4. The iron was not up to temperature or its wattage rating is too small.

Some additional troubleshooting tips follow.1. The solder won't wet (take) because grease, corrosion or is dirt present,clean up the parts, pads, wires and terminals.2. The solder won’t wet because the material is not suitable for soldering, a special solder and/or flux might be required.3. The joint is dull or grainy looking because a part or a wire moved before freezing, physically stabilize the assembly in a holder or by other means.4. The joint is dull or grainy looking because the joint was improperly heated or flux islacking.5. The solder joint has a spike because it was overheated and all the flux burned off.

SOLDER TROUBLESHOOTING

30 WATT SOLDERING IRON 80 WATT SOLDERING STATION

300 WATT SOLDERING IRON

Tinning the iron

Cleaning with wire brush

Cleaning by wiping tipon a damp sponge

A diameter of 0.025inches is common formost electronic work.

Eutectic alloy(lowest melting point)

63% tin, 37% lead

62% tin, 36% lead, 2% silver is preferred for some work

Solder

Tools and materials

WIRES STRIPPED

WIRES TWISTED TOGETHER

TINNING IRON

HEATING WIRE PRIOR TO SOLDERING

SOLDERING TWISTED PAIR WIRE

Temperature controlled iron with grounded tip.

A magnifier ishelpful forinspection.

Solder bridge

Circuit board holder

Desoldering braid Vacuum pump

Desoldering methods

Vacuum desolderingstation

Using desoldering braid

Click the center of the photo to start the video.

Using a vacuum pump


Using a vacuum desoldering station


Clean the pads with desoldering braid

After device removal

Apply the iron, then the solder. Remove thesolder, then the iron. (About 3 seconds per lead)

Soldering


Removing a solder bridge with braid

Spray with flux cleaner and then brush to remove flux residue.

Clean the area


REMOVING EXCESS SOLDER

SHRINKING HEATSHRINK TUBING

PLACE COMPOENTS

APPLY HEAT

APPLY SOLDER

COMPLETED SOLDER JOINTS

COLD SOLDER JOINTS

©2008 The McGraw-Hill Companies, Inc. All rights reserved.

BBasic asic SSkills in kills in EElectricity and lectricity and EElectronicslectronics

Seventh EditionSeventh Edition

Soldering and DesolderingIncluding SMT Rework

Charles A. Schuler

©2008 The McGraw-Hill Companies, Inc. All rights reserved.

VIEW SOLDER FILES ON FOWLER CD

LAB#2 SIMPLE SERIES CIRCUITS

IN THIS LAB WE WILL START WITH A SIMPLE CIRCUIT AND GRADUALY MADE IT MORECOMPLEX. CONSTRUCT THE CIRCUIT SHOWN BELOW ON THE PLYWOOD PROTOTYPE BOARD.

12VDC FROM POWER SUPPLY

Sw R 200Ω

V

VOLTMETER

LED, ANY COLOR

http://www.youtube.com/watch?v=HrG98HJ3Z6wCollin's Lab: The REAL Breadboard

http://www.youtube.com/watch?v=HrG98HJ3Z6w

12VDC

Sw R 200Ω

V

LED

LED’S ARE POLARITY SENSITIVE (MORE ABOUT THIS LATER) MAKE SURE THEY ARE CONNECTED THE WAY I SHOWED YOU.

12VDC

Sw R 200Ω

V

LED

MEASURE THE VOLTAGE USING YOUR MULTIMETER AT THE POWER SUPPLY, ACROSS THE RESISTOR AND THE LED.

VARY THE VOLTAGE FROM THE POWER SUPPLY. WHAT HAPPENS TO THE LED.

12VDC

Sw R 200Ω

V

LED

I

MEASURE THE CURRENT IN THIS CIRCUIT WITH AN AMMETER. AMMETER’SMUST BE PLACED IN THE CURRENT PATH, NOT ACROSS IT.

MOVE THE AMMETER AROUND THE CIRCUIT IS THEIR ANY DIFFERENCE IN THE CURRENT MEASURED?

12VDC

Sw R 200Ω

V

LED

MAKE AN OPEN CIRCUIT BY DISCONNECTING THE LED. WHAT HAPPENS TO THE VOLTAGE AND CURRENT.

I

PLACE A JUMPER WIRE FROM THE RESISTOR ACROSS THE LED. WHAT HAPPENS TO THE VOLTAGE AND CURRENT READINGS.

12VDC

Sw R 200Ω

V

LED

I

PLACE A FUSE HOLDER( WITH FUSE) BETWEEN THE POWER SUPPLYAND THE ON/OFF SWITCH. TRY TO FIGURE OUT A APPROPRIATE AMPERERATING FOR THE FUSE.

12VDC

Sw 200Ω

V

LED

F

NOW REPLACE THE LED WITH A DIFFERENT LOAD, A COMPUTER COILING FAN.CHECK THE VOLTAGE AND CURRENT READINGS WITH THE FAN. ANY DIFFERENCE.WHY?

12VDC

Sw200Ω

V

FAN

F

I

NOW REPLACE THE SWITCH WITH A POTENTIOMETER. THIS WILL ALLOW YOU TO VARY THE VOLTAGE ACROSS THE LOAD, BRIGHTEN OR DIM THE LED, CHANGE THE FAN SPEED

12VDC

Sw 200Ω

V

FAN

F

I

LED

VR

SINCE ALL UTILITY POWER SUPPLIED IS ALTERNATING CURRENT( A/C)AND ALL ELECTRONIC CIRCUITS RUN ON DC WE NEED A MEANS OF CONVERTINGAC TO DC THIS IS DONE WITH THE USE OF A TRANSFORMER. IN OUR CASE WE ARE USING A STEP DOWN TRANSFORMER. TAKING A HIGHER VOLTAGE A/C AND DROPING IT TO A LOWER VOLTAGE A/C. WE THEN CONVERT THIS LOW VOLTAGE AC TO DC WITH A DIODE (OUR FIRST LOOK AT A SIMPLE RECTIFIER).

12V AC

Sw 200Ω

V

FAN

F

I

D1120V AC

VR

D2

IN4001

Wall clocks, mp3 players, electronic sensors, and special devices use 1.5V battery (cell) as power source. We sometimes forgot to buy or replace the battery but no worries because we can design circuits that can convert higher DC voltages to useable 1.5V.The following electronic circuits are possible schematic of 1.5V power sources or regulators.

Simple 1.5V power supplyAround 20mA maximum output current, good in low power application like wall clocks.

Part List:R- 220 ohms 1/4WD - 1N4001 or similar diodeLED - 3mm or 5mm red LEDC - 4.7uF electrolytic capacitorDC - 4V to 6V DC source

LAB#3 BUILD A CONTINUITY CHECKER

HERE WE WILL BUILT A CONTINUITY CHECKER SIMILAR TO THE ONE ONYOUR MULTIMETER. THE LED ( D2) IS THE INDICATOR OF CONTINUITY. RESISTORR1 IS USED TO LIMIT THE CURRENT TO THE LED TO A SAFE LEVEL. D1 PROTECTSTHE LED IF A REVERSE POLARITY VOLTAGE IS ACCIDENTLLY APPLIED. A 9 VOLTPOWER SUPPLY IS USED.

D2 D1

S 180Ω

9V

+

-R1

LAB#4 SERIES/PARALLEL CIRCUITS

CONSTRUCT THE FOLLOWING 3 CIRCUITS, FIND VT, IT, RT, R1, R2, R3, R4, VI TO V4, I1 TO I4, ALSO CALCULATE THESE VALUES AND SEE HOW CLOSELY THEY MATCH YOUR MEASURED RESULTS.

10V

100Ω 100Ω

100Ω100Ω

R1

R3 R4

R2

SERIES CIRCUIT

PARALLEL CIRCUIT FIND RT ,IT, V1,V2, I1,I2

10V100Ω 100Ω

R1 R2

SERIES/ PARALLEL CIRCUIT FIND IT,RT, V1-V6, I1-I6

10V

100Ω 100Ω

100Ω

100Ω

R1

R6

R2

R4

100ΩR3

100ΩR5

LAB#5 SERIES/PARALLEL CIRCUITS: TROUBLE SHOOTING FOR OPEN/ SHORT CIRCUITS

VT

R1 R3

R2

100Ω

2KΩ

1KΩ

WHAT HAPPENS TO THE VOLTAGE/CURRENT VALUES WHEN THE SWITCH IS OPENED IN THIS SERIES/PARALLEL CIRCUIT.

CLOSED Sw10V

WHEN THE SWITCH IS OPEN THIS CIRCUIT IS EQUIVLIENT TO,

VT

R1 R3

R2

100Ω

2KΩ

1KΩ

OPEN Sw

VT

R1

R2

100Ω

2KΩ

FIGURE A

FIGURE B

VT10V

R1 R3

R2

100Ω

2KΩ

1KΩ

OPEN SwIT

WHEN THE SWITCH IS OPEN IN FIGURE A, R3 IS NO LONGER PART OF THE CIRCUIT

mAVRVI

KRRR

T

TT

T

76.4210010

1.221

NOW WE ARE LEFT WITH A SERIES CIRCUIT.

VVVVVVmARIV

VmARIVVmARIV

III

T

T

T

T

1052.9476.010000

52.9200076.4476.10076.4

21

333

22

11

21

IF THE SWITCH IS CLOSED, A DIRECT SHORT IS CREATED WHICH TAKES R2AND R3 OUT OF THE CIRCUIT.

VT10V

R1 R3

R2

100Ω

2KΩ

1KΩ

CLOSED Sw

V1=10VV3=0V

V2=0V

VKARIVVKARIV

VVV

mAAVRVI

T

TI

010020

10

1001.010010

333

222

1

1

VT10V

R1 R3

R2

100Ω

2KΩ

1KΩ

CLOSED Sw

LOOP1 LOOP2

76610666.100103102100

2000100020001000100

21

33

6

32

321 RR

RRRR

LOOPLOOPOFRESISTANCERRFIND

T

T

T

VARIVVFIND

mAAVRVI

IFIND

T

T

TT

T

3.110013.0,

13013.076610

111

FIND V2, FROM KIRCHOFF’S VOLTAGE LAW FOR LOOP1

mAAVRVI

VVVVVVVVV

T

T

35.41035.420007.8

7.83.110

3

2

22

12

21

FIND V3, ONE WAY IS TO FIND I3 FIRST FROM KIRCOHOFF CURRENT LAW.

VRIVNOWmAAAIII

CNODEATIII

T

T

65.8100000865.065.800435.0013.0

333

23

32

V2 AND V3 SHOULD BE THE SAME SINCE THEY ARE IN PARALLEL

V2=8.7V V3=8.65V SO WHERE’S OFF 0.05V,WHO CARE’S!

120VAC 12VAC

1N4001

RL12KΩ

A B

C

LAB#6 RECTIFICATION PART 1

HALF WAVE RECTIFIER

MEASURE AND DRAW WAVEFORMS FROM AN OSCOPE AT POINTS A TO C ANDB TO C. ALSO MEASURE CURRENT AT POINTS A,B,C. MEASURE VOLTAGES WITH AND WITHOUT THE LOAD RESISTOR.


120VAC 12VAC560Ω

560Ω

D1

D2

RL12KΩ

A

B

C

D

FULL WAVE RECTIFIER

AGAIN MEASURE AND DRAW WAVEFORMS FROM PTS. A TO B AND C TO D. WHAT IS THEDIFFERENCE THIS TIME? TRY DIODES WITH DIFFERENT VOLTAGE RATINGS. WHAT HAPPENS?

120VAC


FULL WAVE RECTIFIER WITH CENTER TAPPED TRANSFORMER

12VAC

D1

D2

RL12KΩ

A

B

C

D

24VAC

AGAIN MEASURE AND DRAW WAVEFORMS FROM PTS. A TO B AND C TO D.

120VAC12VAC

D1 D2

RL12KΩ

A

B

C

D

D3 D4


FULL WAVE BRIDGE RECTIFIER

MEASURE AND DRAW WAVEFORMS FROM PTS. A TO B AND C TO D, THEM MEASUREVOLTAGE WITH VOM AT A TO B AND C TO D.

707.2 RMSPP VVREMEMBER HINT: OSCOPE MEASURES VPP, VOM MEASURES RMS

RECTIFICATION AND FILTERS PART 5

120VAC12VAC

D1 D2

RL12KΩ

A

B

C

D

D3 D4

ADD ONE CAPACITOR WITH A VALUE OF 47uF. MEASURE VOLTAGE, WAVEFORMACROSS C TO D, WHAT,S THE DIFFERENCE, HAS THE RIPPLE IMPROVED?

47uF

120VAC12VAC

D1 D2

RL12KΩ

A

B

C

D

D3 D447uF 10uF


ADD SECOND CAPACITOR OF ABOUT 10uF REPEAT RESULTS FROM PART 5


120VAC 12VAC

D1 D2

RL12KΩ

A

B

C

D

D3D4

47uF 47uF

L

NOW ADD AN INDUCTOR, CAN BE FROM 1 TO 8 H. REPEAT RESULTS FROM PART 6.CALCULATE fr RESONANCE FREQ. FOR THIS CIRCUIT. THIS IS THE f WHERE THE MAX.TRANSFER OF POWER OCCURS BETWEEN THE LINE AND THE LOAD.

LCfR 2/1

LAB#7 TRANSISTOR OPERATION

http://www.youtube.com/watch?v=3N3ApzmyjzECircuit Skills: Perfboard Prototyping

http://www.youtube.com/watch?v=4YE8rGuLCtUCollin's Lab: DIY iPad Stylus

http://www.youtube.com/watch?v=3N3ApzmyjzE

http://www.youtube.com/watch?v=4YE8rGuLCtU

LAB #8

Filament Light Dimmer Circuit

Filament Light Dimmer CircuitThis simple triac dimmer can be used to control incandescent filament lamps up to 200W. The circuit operates on the phase-control principle.

PARTS LIST

R1 10kΩ 0.5W

R2 100Ω 0.5W

VR1 500kΩ Potentiometer

C1 330n (0.33µF)

C2 100n (0.1µF)

D1 DB3 Diac

Q1 BT136 Triac

L1 Filament Light

The main control is provided by VR1. This determines the rate at which C1 charges and hence the point along the AC waveform at which the voltage on C2 reaches the breakdown voltage of the diac (D1), which is when the triac is triggered.

Website for this imagehackedgadget.tistory.com

http://hackedgadget.tistory.com/entry/A-Simple-and-Cheap-Dark-Detecting-LED-Circuit

A Simple and Cheap Dark-Detecting LED Circuit

LTR-4206E phototransistor

Resistance Measurement Analog LED Meter This is a LED Analog Meter, This can be used as a Resistance Meter and Low Impedance Voltmeter for Battery Levels. To measure battery voltage, the R5-R12-R17 etc. part of the Reference Resistor Divider Network can be modified to suit. Shown here is for 4 LEDs, Use Three LM324 for 12 or More LEDs and Cascade

In the Knight Rider circuit, the 555 is wired as an oscillator. It can be adjusted to give the desired speed for the display. The output of the 555 is directly connected to the input of a Johnson Counter (CD 4017). The input of the counter is called the CLOCK line. The 10 outputs Q0 to Q9 become active, one at a time, on the rising edge of the waveform from the 555. Each output can deliver about 20mA but a LED should not be connected to the output without a current-limiting resistor (330R in the circuit above). The first 6 outputs of the chip are connected directly to the 6 LEDs and these "move" across the display. The next 4 outputs move the effect in the opposite direction and the cycle repeats. The animation above shows how the effect appears on the display. Using six 3mm LEDs, the display can be placed in the front of a model car to give a very realistic effect. The same outputs can be taken to driver transistors to produce a larger version of the display

http://www.technologystudent.com/elec1/count1.htm

THE 4017B DECADE COUNTER

http://www.technologystudent.com/elec1/count1.htm

LED Traffic LightsThe LED traffic Light circuit controls 6 LEDs (red, yellow and green) for both north/south directions and east/west directions. The timing sequence is generated using a CMOS 4017 decade counter and a 555 timer. Counter outputs 1 through 4 are wire ORed using 4 diodes so that the (Red - North/South) and (Green - East/West) LEDs will be on during the first four counts. The fifth count (pin 10) illuminates (Yellow - East/West) and (Red - North/South). Counts 6 through 9 are also wire ORed using diodes to control (Red - East/West) and (Green - North/South). Count 10 (pin 11) controls (Red - East/West) and (Yellow - North/South). The time period for the red and green lamps will be 4 times longer than for the yellow and the complete cycle time can be adjusted with the 47K resistor. The eight 1N914 diodes could be substituted with a dual 4 input OR gate (CD4072).

This 40W fluorescent inverter project is powered by 555 timer IC and used to drive fluorescent tubes, compact fluorescent lamp (CFL) and even defective fluorescent tube.

From a 12V supply voltage, timer IC generates square wave voltage of about 4.8kHz. The primary winding (16 turns of #22 AWG) will generate current pulses of about 4A, and in return will induce a high voltage at the secondary winding (450 turns of #30 AWG) of the inverter. This voltage is enough to strike the fluorescent tube even if the filament is not heated thus very suitable to tubes with broken filaments ( burnt out filaments).

This inverter project is very suitable in lighting defective fluorescent tubes, thus helps in minimizing tubes disposal problems. The inverter also can light two 40W tubes in series.

LAB #8

Smoke detectors are generally used in advanced alarm systems. Most of this professional devices use gas-detectors, ionization rooms or radioactive elements as sensors. In this circuit we are not using any of this complicated components. Instead of these, we are using two LDRs and one LED. LM1801 special-purpose IC ,which is designed especially for smoke detectors, this helps us build this circuit by using the minimum number of components. It includes one internal zener supply, two reference voltage outputs, one voltage comparator, fixing diodes and one 500mA output transistor.

BUILD YOUR OWN SMOKE DETECTOR

This 40W fluorescent inverter project is powered by 555 timer IC and used to drive fluorescent tubes, compact fluorescent lamp (CFL) and even defective fluorescent tube.

From a 12V supply voltage, timer IC generates square wave voltage of about 4.8kHz. The primary winding (16 turns of #22 AWG) will generate current pulses of about 4A, and in return will induce a high voltage at the secondary winding (450 turns of #30 AWG) of the inverter. This voltage is enough to strike the fluorescent tube even if the filament is not heated thus very suitable to tubes with broken filaments ( burnt out filaments).

This inverter project is very suitable in lighting defective fluorescent tubes, thus helps in minimizing tubes disposal problems. The inverter also can light two 40W tubes in series.

CONST 150 LAB 1 SOLDERING

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