The variable resistor increases the amount resistance
Question 1
a)
2 - Pulse
4 - Ground
1) Unlike a transformer that provides only AC coupling, the Opto-isolator allows DC coupling and can provide any desired degree of electrical isolation and protection from serious overvoltage conditions in one circuit affecting the other.
2) Another advantage is that power supplies for the input and output sides can be different and completely isolated from each other. This reduces the contamination of certain kinds of electrical noises eg. It reduces the chance of creating a ground loop.
d. 0010 1001
Question 3:
b)
After the current passes through the variable resistor, it charges the firing capacitor. When the capacitor builds up a certain amount of charge, it reaches the voltage level required to conduct current in the triac. The firing capacitor then discharges, making the triac conductive. As discussed, turning the dimmer switch knob controls the contact arm on the variable resistor. When the knob is set to dim, the variable resistor increases the amount of resistance. Therefore, less current reaches the capacitor to charge. This in turn, increases the amount of time before the triac will be able to conduct. By the time the capacitor is charged enough to make the triac conductive, the AC current is at the desired point in the cycle. If you set the knob to bright light, the variable resistor provides less resistance and the capacitor reaches the required voltage quicker in the AC cycle.
As soon as the AC current reaches the next zero voltage point, there is nothing driving current through the triac, so the electrons stop moving. The depletion regions reform, and the triac no longer conducts until the voltage builds up on the gate again.
Fig 5: output voltage = 0.5*6000/1000 = 3Volts.
Fig 6: output voltage = input voltage = 0.5 volts
ASCII is a way for a computer to convert letters and characters to and from. So that they can be stored inside the computer and manipulated by the computer. A set of codes, known as "ASCII" (American Standard Code for Information Interchange) are used.
BCD
(C)
Below is 3 phase full wave bridge rectifier circuit with 3 phase AC input
Regulated Power Suppliers
Motor Controls
