Practical Activity #1

Practical Activity #1 Diode and LED Testing

▲+V_s = 6.30 V

▲-V_s = - 6.30 V

Figure 1

1. Select the standard values of the resistors R₁ and R₂ to provide the current flowing through 10-15 mA.

▲Standard resistors R₁ = 455.9 Ω

▲Standard resistors R₂ = 451.8 Ω

V_s : logic ‘0’ (+V_s) LED : ‘D₁’ is on ‘0’

logic ‘1’ (-V_s) ‘D₂’ is on ‘1’

Conclusion :

- If V₂ ‹ V₁; The output is near the negative supply voltage (-V_s) and make the LED ‘D₂’ is on.

- If V₁ ‹ V₂; The output is near the positive supply voltage (+V_s) and make the LED ‘D₁’ is on.