Materials And Equipment Needed  Safety Considerations

MATERIALS AND EQUIPMENT NEEDED

Provide each student team with the following:

• Safety goggles
• Solar cell recharging units
  
• 555 Timer
  
• Resistors, capacitors, potentiometer and switches
• LEDs
• Soldering irons and solders
• Miniature cutters and pliers

Additional materials and equipment specific for KSBs are listed in the corresponding KSBs.

SAFETY CONSIDERATIONS

In the module, safety goggles must be worn for some of the activities involving chemical and electrical wiring (wire cutting and soldering). Take time to explain the safe use of electronic instruments and laboratory tools. Check the policy in your district for students eating foods while involved in classroom activities.

Circuit Digram

A possible electric circuit for the safety light system is shown here for your reference.

Component List

IC1	NE555 Timer,
R1	100 Ώ,
R2	4.7KΏ,
R3	50 KΏ trim potentimeter,
R4	220 Ώ,
R5	220 Ώ,
C1	10 mF,
C2	0.01 mF,
D1,D2	Light emiting diode,
SW1,SW2	SPDT switch IC Socket