1. Design a zener regulator to meet these specifications: Load voltage is 6.8 V, source voltage is 20 V, and load current is 30 mA.
2. A TIL312 is a seven-segment indicator. Each segment has a voltage drop between 1.5 and 2 V at 20 mA. The supply voltage is +5 V. Design a seven-segment display circuit controlled by on-off switches that has a maximum current drain of 140 mA.