2. Switch on the supply. 3. Set the MT1, MT2 voltage by varying the RPS.Next voltage applied to Gate. 4. The TRIAC is ON .Note down the breakdown voltage. 5. Increase the MT1, MT2 voltage and corresponding current is noted. 6. The above steps are repeated for different values of VBO
RIT EE6611 – Power Electronics and Drives Laboratory 24
25 EE6611 – Power Electronics and Drives Laboratory RIT RESULT INFERENCE REVIEW 1. Expand TRIAC and mention its features. 2. Is TRIAC a bidirectional device-Justify 3. What is the role of gate terminal in operation of TRIAC? 4. What are the advantages and disadvantages of TRIAC? 5. What do you understand by sensitivity of gate? 6. Why TRIAC is less sensitive with negative gate current in first quadrantand positive gate current in third quadrant?
1. Depletion-type MOSFET 2. Enhancement-type MOSFET It has very high input impedance. The gate draws a very small leakage current, in the order of nanoamperes. The current gain, which is the ratio of drain current, I D ,to input gate current, I G , is typically on the order of 10 9 . However, the currentgain is not an important parameter. The transconductance, which is the ratio of drain current to gate voltage, defines the transfers characteristics and is a very important parameter. There are three regions of operation: 1. Cutoff region 2. Pinch-off region or saturation region 3. Linear region Due to the high drain current and low drain voltage, the power MOSFETs are operated in the linear region for switching actions. In the saturated region, the drain current remains almost constant for any increase in the value of V DS and the transistors are used in this region for voltage amplification. CHARACTERISTICS OF MOSFET 4 Exp. No. : Date :
RIT EE6611 – Power Electronics and Drives Laboratory 28 TABULAR COLUMN TRANSFER CHARACTERISTICS S.No V GS =….(V) V GS =….(V) V DS (mV) I D (mA) V DS (mV) I D (mA) DRAIN CHARACTERISTICS S.No V DS =….(V) V GS (mV) I D (mA) MODEL GRAPH TRANSFER CHARACTERISTICS DRAIN CHARACTERISTICS
RIT EE6611 – Power Electronics and Drives Laboratory 29 EQUIPMENT REQUIRED S.No. Name Range Type Quantity 1 MOSFET IRF840 1 2 Regulated Power Supply (0-30) V 1 3 Voltmeter (0-30) V MC 1 4 Voltmeter (0-30) V MC 1 5 Ammeter (0-50)mA MC 1 6 Resistor 1 kΩ 1 PROCEDURE 1. Make the connections as per the circuit diagram.
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- Summer '19
- Alternating Current, power supply, Switched-mode power supply, RIT, –Power Electronics, Drives Laboratory