In this project you will design a simple relay-activated circuit used to quickly switch an electrical load from a solar array to backup batteries when the array voltage drops too low. For example, if a cloud obscures a solar array temporarily, the output voltage will sag. To ensure continuous operation of the load, a relay circuit might be used to switch to battery backup until the voltage of the solar array returns to normal. Basically, your “design” will consist of figuring out the inductance necessary on the relay coil to meet the design specifications The relay/circuit you will use is shown in Figure 1. The design specifications: 1) The solar cell system normally operates at 24 V DC when fully illuminated. 2) The relay has a winding resistance of 60 Ω. But the inductance of the relay coil is to be determined by you. 3) The relay switches instantaneously when the coil current drops to 0.3 A or below. Your job: 1) Calculate the value of coil inductance, L, that will ensure that if the array voltage suddenly drops to 16 V, the relay will switch the load to battery backup within 0.25 s. 2) Using the value of L you calculated, determine how long it would take to switch to backup power if the array voltage abruptly changed to 0 V. 3) Find a standard relay that has the coil resistance and inductance that will meet these specs. If you can’t find anything close to your calculated value, then find a relay with different R and L that will still work in this application. Having a little trouble. Where should I start?