Construction Techniques

Revision

• Be able to recognise resistors, capacitors (including fixed, variable and electrolytic types), inductors, transformers, diodes, transistors, integrated circuits, crystals, microphones and loudspeakers.

• Can you identify the following and fill in the blanks

Components name	Component picture	Circuit diagram
		None required
		None required

• Know that soldering is a method of joining metal wires and components using a hot soldering iron to melt the solder.

• Know that many solders contain a flux to help the solder to flow and to remove the layer of oxide on the surfaces to be joined.

• Know that some metals are easy to solder and some are difficult.

• Know that the tip of the soldering iron has to be cleaned and 'tinned' before use to remove traces of oxide and to improve the conduction of heat to the joint.

• Know that it is necessary to make joints reasonably quickly to avoid damage to components, and that most construction faults stem from poor (dry) joints.

• Know the resistor colour code, colours 0 to 9 with gold as multiplier. Recall silver (10%) and gold (5%) as tolerance bands.

• Know how to read the value of a resistor between 1 ohm and 9 M ohms from the E12 series.

Here are a few questions

• A resistor has bands Orange, Orange, Black and Gold. What is value according to the three main rings ? What is its maximum and minimum values according to the tolerance ring ?

• A resistor has bands Brown, Grey, Orange and Gold. What is value according to the three main rings ? What is its maximum and minimum values according to the tolerance ring ?

• A resistor has bands Yellow, Violet, Red and Silver. What is value according to the three main rings ? What is its maximum and minimum values according to the tolerance ring ?

• What bands would a 22kohm 10 % resistor have?

• What bands would a 150kohm 10 % resistor have?

• What bands would a 5k6 5 % resistor have?

• What bands would a 82ohm 5 % resistor have?