(d) The circuit shown in FIGURE 3 is part of the interface of a relay output module. Ib is 1 mA and Vcc is 9 V. The relay requires a minimum of 50 mA to energise.
Complete the values of the assumptions listed below in order to calculate:
• Voltage across R1 • value of Ri • voltage across the relay coil • voltage across R2 • value of R2 • collector of current
Logic '1' = V Logic '0' = V
Transistor forward current gain h_i_e = LED current = 10 mA
LED voltage drop at 10 mA = V Base/emitter voltage = V Collector emitter voltage when transistor is on = 1 V
This posting contains the solution to the given problems.