Assignment No. 2 1. The circuit shown below is used for controlling furnace temperature. If the pedestal voltage (i.e. voltage from Vp to ground in the figure), is zero, calculate the firing angle, θ and the rms load voltage. If the pedestal voltage is equal to 3 V, what is the new firing delay angle, θ? 2. Design the the circuit shown such that UJT will fire at 45° firing delay angle at the given values of RT & CT . Based on your design, determine the voltage at the load for a firing delay angle of 45°. Assume; UJT stand-off ratio is 0.63 and the AC line is 220 V, 50 Hz.
