In the Class A commutation, the commutating components L and C are used to turn off the SCR. When the load resistance of very small value is used, the inductor L and capacitor C are connected in series with load. Similarly the load resistance of high value is used; the load resistance is connected across capacitor. The value of L and C are selected that the circuit becomes under damped. The current attains zero value at point A as shown in the figure B.
The power circuit diagram of static AC Circuit Breaker is shown in the Figure. The control circuit is not given in this Figure. The SCR is used for ON and OFF of the circuit.
The basic circuit for DC circuit breaker is shown in the figure A. The principal of DC circuit breaker is Class C commutation. The SCR 1 is main SCR. When it is necessary to break load current, the SCR 1 is turned off. There is no control circuit given in this figure for simplification.
The basic circuit for the AC Time delay circuit is shown in the figure A. Let us consider that the switch is in the reset position.
The
basic circuit of the Jones chopper is
shown in the figure A. The Class
D commutation circuit is used in the Jones chopper.
The SCR T1 is main SCR whereas SCR T2, diode D1, capacitor C and auto – transformer T makes commutating circuit for SCR T1. The inductor L1 and L2 are closely coupled and they provide sufficient energy to capacitor to turn off main SCR T1.
The type E chopper is a four quadrant chopper. The type E chopper is parallel combination of two type C chopper. The combination of chopper CH1, chopper CH2, diode D1 and diode D2 makes one type C chopper and other is made from chopper CH3, chopper CH4, diode D3 and diode D4. The DC supply is short circuited if chopper CH1 and CH4 or chopper CH2 and CH3 is simultaneously switched on.
The type D chopper is two quadrant chopper as it operates in the first and fourth quadrant. When the load voltage and current becomes positive, it operates in the first quadrant. Similarly, when load voltage becomes negative but load current is positive, it operates in the fourth quadrant. The two quadrant type B chopper or type D chopper is shown in the figure A.
The type C chopper is parallel combination of type A and type B chopper. Here, only power circuit is shown, control circuit is not given. The output voltage is always positive but output current either positive or negative in this type of chopper therefore it works in first as well as second quadrant.
The type B chopper works in second quadrant it means that the output voltage positive and output current negative. The power output is negative it means that the power flows from load side to supply side. The type B chopper is also called as step up chopper because the output voltage is greater than the input voltage. Here, only power circuit of type B chopper is shown.
The speed control of DC series motor by using chopper is shown in the figure A. This speed control is achieved through constant frequency control or variable frequency control.
The speed control of the Slip ring induction motor by chopper is shown in the figure A. The power circuit diagram of speed control of slip ring induction motor control is shown in the figure.
The power circuit diagram of the type A chopper / class A chopper is shown in the figure A. The commutation circuit is not shown in this figure A. Type A chopper operates in the first quadrant, it means that output voltage and output current both are positive. Type A chopper is called as single quadrant chopper. The power flows from supply to load side. Type A chopper and class A chopper both are same.
The firing of SCR is done by various method. Firing of SCR is done by UJT full wave is explained here. The firing of SCR is done by UJT half wave circuit is one of the methods.
The firing of SCR is done by various method. Firing of SCR is done by UJT half wave is explained here. The firing of SCR is done by UJT half wave circuit is one of the methods.
The power point of commutation methods of SCR is given here. The commutation of SCR is done by either forced commutation or natural commutation.
The firing angle control of SCR is done by RC phase shift control. The working of RL phase shift control is explained here.
The firing angle control of SCR is done by RL phase
shift control. The working of RL phase shift control is explained here.
The configuration of chopper is done according to
direction of output voltage and output current.
There are following types of DC chopper according to output voltage and output current with respect to standard input DC voltage. The configuration of chopper is done according to direction of output voltage and output current.
There are following methods for DC Chopper Voltage
Controls.
DC Chopper Voltage Control: Constant Frequency Control
The fan regulator circuit or light dimmer circuit is one which intensity of light or fan speed controlled by regulator. It is simply we called as fan regulator. The light intensity is controlled by fan regulator so it is also called as light dimmer.
The corridor
lighting is proper sequence of lighting point for control illumination at
forward steps. The corridor lighting is used in the passage.
Lamps, holder, two-way switches, wire, connector, cutter
The main function of the DC chopper
is to convert fixed DC voltage into variable DC voltage. It is similar to DC
transformer.
The function of the DC chopper is to convert fixed DC into variable DC. A DC chopper is connected between supply source and load.
The wiring diagram of twin tube light is shown in the Figure. The Twin tube light is generally used in the textile industry / diamond factory where high level of illumination required.
Here, the wiring diagram of three lamps are controlled by six switches are given. Each lamp is controlled by two switches. It is similar to stair case wiring with multiple circuit connected in parallel.
Here, we explain lamp control by remote location. Here the diagram of one single lamp controlled by three different switches at different location is given. Lamp controlled is done by any of the three switches.
Here, the schematic and wiring diagram of staircase wiring is shown in the Figure. There are 2 two-way switches used in this diagram and they are connected such that when one switched is change its position, lamp is ON or OFF.
The go down wiring is explained here by two diagram – schematic diagram and wiring diagram. The schematic diagram is single line diagram and wiring diagram is actual wiring connection diagram.
The working of automatic star delta starter is explained here. The control circuit of the automatic star delta starter consists of three contactors – main contactor, star contactor and delta contactor. It also required one timer for switching of motor from star to delta operation.
In this post, working of forward-reverse Starter Control circuit explained. The forward reverse starter is applicable where frequent forward and reverse of induction motor is necessary. The control circuit of forward-reverse starter consists of two contactors, one for forward direction and other for reverse direction. The complete working of Forward-Reverse Starter is explained in following steps.
In this post, the working of direct on line starter is given. It is simplest type of AC starter as it required only one contactor to control the starting current. It is also cheapest starter of all types of AC motor starter.
In this post, working of semi-automatic
star delta starter is given. It consists of 3 contactors – main contractor,
star contactor and delta contact.
Here the working of semi-automatic star
delta starter is explained in steps.
Push on button.
