PERFORMANCE STANDARDS

• Tools are used according to task undertaken.

• All safety procedures in using tools are observed at all times.

• Malfunctions, unplanned or unusual events are reported to the supervisor.

What Do You Already Know?

Let us determine how much you already know about checking conditions of tools and equipment. Take this test.

What Do You Need To Know?

Read Information Sheet 2.1 very well. Then find out how much you can remember and how much you learned by doing Self-check.

Information Sheet 2.1

USING TOOLS BASED ON THEIR FUNCTIONS AND OPERATION

Whenever you perform a task in the workshop you must use personal protective clothing and equipment (PPE) that are appropriate for the task and which conforms with your local safety regulations and policies.

Your skill in using tools and equipment will make your work less difficult and ensure that tasks are performed properly and safely.

Hand Tools

o screwdrivers, needle-nose pliers

Diagnostic Tools

o Analog or digital Volt-Ohm-Milliammeter, power supply

Safety check

• Do not use flammable cleaners or water on electrical equipment.

• Make sure designated walkways are kept clear of any obstructions.

• Always wear protective clothing and use the appropriate safety equipment.

• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks.

• Precautions should always be observed when using hand and power tools.

• Hand and power tools should always be stored when not in use.

• Always use hand and power tools properly.

• Test equipment is used when assembling a circuit to ensure it is working properly.

• When working in the workshop, everyone is responsible for safety.

• Safe practices should be observed when using hand and power tools.

• Safe practices should be observed when working on any electronic circuit or equipment.

Proper Use of Hand Tools

When using hand tools, always observe the following precautions:

1. Always use the proper tool for the job. Use the right type and size tool for each application.

2. When carrying tools, always keep the cutting edge down.

3. Keep hands clean when using tools. Avoid grease, dirt, or oil on hands when using any tool.

4. Clamp small pieces when using a hacksaw, screwdriver, or soldering iron.

5. Avoid using chisels and punches with mushroomed heads.

6. Never use a file without a handle.

7. Never use plastic-handled tools near an open flame.

8. Keep metal rules clear of electrical circuits.

9. Disconnect all electrical devices by pulling directly on the plug, never the cord.

10. When cutting wire, always cut one wire at a time to avoid damaging the cutting tool.

11. Do not over tighten screws because the threads may become stripped.

Proper Use of Power tools

When handling the power tools, always observe the following precautions:

1. Ensure all power tools have grounded three-prong plugs or an insulated housing approved by UL (Underwriters Laboratories).

2. Make all adjustments to the machine before turning it on.

3. Double-check any special setups before applying power.

4. Keep all safety guards in proper position at all times.

5. Clean the work area before using a power tool and keep it clean.

6. Keep power tools clean, and put away them when they are not in use.

7. Avoid treating power tools roughly, dropping them, or hitting them against things.

8. Keep all power tools in good condition with regular maintenance.

9. When finished using a power tool in the workshop, find a safe place to set it down when working.

Proper Use of Soldering Iron

When soldering, always observe the following precautions:

1. Always assume the soldering iron is hot. Never touch the tip to see if it is hot.

2. Always place the soldering iron in its holder when idling.

3. Never shake excess solder off the tip; wipe it on a damp sponge or approved tip cleaner.

4. Never pass a soldering iron to another person; place it in the holder and let the other person take it from there.

5. Never solder on a circuit that has power applied to it.

6. Always use a grounded-tip soldering iron.

In many types of work, hand tools are used every day. They make work easier and allow people to be more efficient. However, majority of students often fail to see the hazards these tools can introduce. In this module "Hand Tool Safety" shows workers how accidents can be significantly reduced by reviewing the various hazards that are associated with specific types of tools.

Operation Sheet 2.1

Instruction:

1. Do the following Operation Sheets:

a. Procedure in using a soldering iron

b. Mounting and soldering of components on PCB

c. Disassembly and assembly of the circuit

Procedure in using a soldering iron

The Ten Soldering Commandments

In truth, the Ten Soldering Commandments are more like guidelines than commandments. But if you heed them, things go well with your solder joints, your children’s solder joints and your children’s children’s solder joints. So let it be written; so let it be done:

I. Thou shalt wear eye protection whenever thou solderest, lest thy get molten solder in thine eye.

II. Thou shalt not touch the heated end of thy soldering iron, lest thy burn thyself.

III. Thou shalt not fashion molten solder into false globs.

IV. Thou shalt wash thy hands after thou solderest, to remove vile contamination from upon thy hands before thou eatest.

V. Thou shalt provide bright illumination upon thine objects which thou solderest, that thou might see clearly the way unto which the solder may be applied.

VI. Thou shalt not spill thy excess solder upon thy neighbour’s pad lest thy create unintended pathways through which current may flow.

VII. Thou shalt not leave thine hot soldering iron unattended.

VIII. Thou shalt not covet thy neighbour’s professional-grade temperature-controlled soldering station.

IX. Thou shalt not apply solder directly upon thine soldering iron, but shalt instead apply solder to the objects which thou solderest, that their heat may melteth thy solder.

X. Thou shalt always place thine hot soldering iron in a suitable holder.

1. Preparing the soldering iron

a. Place the soldering iron on the stand before plugging it.

b. Wait a few minutes for the soldering iron to attain its operating temperature of about 4000C.

c. Wipe the tip of the soldering iron on the wet damp sponge

d. Melt a little solder (soldering lead – 60/40) on the tip of the iron.

e. Wipe again the tip of the soldering iron on the wet damp sponge.

2. Soldering technique

a. Hold the soldering iron like a pen, near the base of the handle.

b. Touch the soldering iron onto the joint to be soldered.

c. Apply a small amount of solder onto the joint.

d. Remove the solder, then the soldering iron, while keeping the joint in still position.

e. Inspect the joint closely. It should look shiny and with a volcano shape.

Operation Sheet 2.2

Basic Soldering Lessons

The most common form of soldering when creating electronic projects is soldering component leads to copper pads on the back of a printed circuit board (PCB), If you can carry out that task, you’ll have no trouble with other types of soldering, such as soldering two wires together or soldering a wire to a switch terminal.

The following steps outline the procedure for soldering a component lead to a PCB:

1. Pass the component leads through the correct holes. Check the circuit diagram carefully to be sure that you have installed the component in the correct location. If the component is polarised (such as a diode, electrolytic capacitor or integrated circuit) verify that the component is oriented correctly. You don’t want to solder it in backward.

2. Secure the component to the PCB. If the component is near the edge of the board, the easiest way to secure it is with a crocodile clip. You can also secure the component with a bit of tape.

3. Clamp the PCB in place with your vice. Turn the board so that the copper-plated side is up. If you’re using a magnifying glass, position the board under the glass.

4. Make sure that you have adequate light. If you have a desktop lamp, adjust it now so that it shines directly on the connection to be soldered.

5. Touch the tip of the soldering iron to the pad and the lead at the same time. You have to touch the tip of the soldering iron to the copper pad and the wire lead. The idea is to heat them both so that solder flows and adheres to both. The easiest way to achieve the correct contact is to use the tip of thesoldering iron to press the lead against the edge of the hole.

6. Let the lead and the pad heat up for a moment. They take only a few seconds to heat up sufficiently.

7. Apply the solder to the lead on the opposite side of the tip of the soldering iron, just above the copper pad. The solder begins to melt almost immediately. Don’t touch the solder directly to the soldering iron. If you do, the solder melts immediately, and you can end up with an unstable connection, often called a cold joint, where the solder doesn’t properly fuse itself to the copper pad or the wire lead.

8. Feed just enough solder to cover the pad when the solder begins to melt. As the solder melts, it flows down the lead and then spreads out onto the pad. You want just enough solder to cover the pad completely, but not enough to create a big glob on top of the pad. Be stingy when applying solder: too much solder is a more common problem than too little. Adding a little more solder later if you don’t get quite enough coverage is a lot easier than removing too much solder.

9. Remove the solder and soldering iron and let the solder cool. Be patient – the solder takes a few seconds to cool. Don’t move anything while the joint is cooling. If you inadvertently move the lead, you create an unstable cold joint that you have to resolder.

10. Trim the excess lead by snipping it with wire cutters right above the top of the solder joint. Use a small pair of wire cutters so that you can trim it close to the joint.

Click this link to learn more about Intro to Soldering

Disassembly and assembly of the circuit

Desoldering

At some stage, you will probably need to desolder a joint to remove or reposition a wire or component. The easiest and most common way is the use of desoldering pump. Shown below is the proper way of removing electronic components from the circuit using a desoldering tool.

Removing components in PCB using a desoldering pump (solder sucker)

1. Set the pump by pushing the spring-loaded plunger down until it locks.

2. Apply both the pump nozzle and the tip of your soldering iron to the joint.

3. Wait a second or two for the solder to melt.

4. Then press the button on the pump to release the plunger and suck the molten solder into the tool.

5. Repeat if necessary to remove as much solder as possible.

6. The pump will need emptying occasionally by unscrewing the nozzle.