Homework 1 - Solution

Document Content and Description Below

roblem 1 (15 points): Design a circuit with one input voltage, ??? , such that,  a red LED lights up when ??? exceeds +3 V  a green LED lights up when ??? exceeds +8 V The LEDs each have a fo... rward voltage drop of 1.5 V and maximum current limit of 25 mA. You can only use one voltage source with ?? = 10 V. You can use any number of resistors and op amps. Clearly draw the circuit and show the component values. Solution: There are multiple ways of designing this; below is one solution. For each op amp: use +10 V and 0 V (i.e. ground of the source) as supply voltages, ??? and ???, respectively. L2 is red LED, L1 is green. Choose, Vcc = 10 V. R1, R2, R3 will have the ratio 2:5:3. R6 and R7 are each 10−1.5 0.025 = 340 Ohms or more. [Show More]

Last updated: 1 year ago

Preview 1 out of 7 pages