Single phase double wound copper transformer having primary 230VAC and secondary 115V AC with a rated capacity of 1KVA. The primary and secondary terminals are brought out for conducting laboratory experiment with legend printed for convenience. This is assembled in a powder coated MS metal box.
Specifications:
This is a variable auto transformer. This is also called as Dimmer-stat. This is used to vary the output voltage by rotating a knob placed above this instrument. The output voltage can be varied from 0 to 270V AC, when its input terminals are connected to 230V AC. It can deliver 6A of current at its peak rated voltage. The entire instrument is assembled in a sheet rolled powder coated MS metal box with separate screw terminal for earth connection.
Loading capacitor, is a capacitor bank with step variation. This is required when experimenting to determine the output characteristics of devices like a transformer etc. More particularly while experimenting to determine the power factor measurements in single-phase electrical circuits.
This is a loading capacitor, where by the capacitance in a load circuit can be varied in the range of 2uF to 16uF @ 230V AC, in 8 steps. The variation in capacitance can be obtained by suitable patch cord mechanism. This is suitably protected with necessary fuse arrangement. The terminals are suitably brought out on a 4mm Banana sockets for easy interconnections.
3 point DC starter is a unit intended to limit the starting current in a DC circuit. This starter is a must for any DC motor applications. This starter has three functions.
(a) To provide series resistance in a DC circuit when this starter is in START position. I.e. In STARTposition full resistance is included, and is reduced to zero ohms when the handle is moved to ON position, in discrete steps. The starter is held in ON position by an electromagnet. At this ON position the DC circuit gets its full current from the DC Rectifier unit. In the case of a DC motor, this isconnected in series with the armature circuit, to limit the starting current and eventually this resistance is CUTOUT, from the circuit. There by enabling the motor to run at it’s full armature current. Therefore this starter acts as a first order protection circuit, in between a DC rectifier unit and the DC circuit.
(b) No Volt Coil (NVC) – This is normally connected to Field circuit in a DC motor. In case of a failure in current in this circuit, for any reason, namely accidental tripping, or unintentional break in field circuit, this coil will provide a signal to the electromechanically held arm (handle) to release, and the starter is switched to OFF position, thereby providing safety to the system.
(c) Over Load (OL) release switch – This is connected in series with the armature circuit. In case of current beyond the rated current of this coil in the circuit, this automatically trips the electromagnet, which is holding the handle in ON position. Thereby tripping the starter from being over loaded
Varieties of meters are available for making suitable measurements of electrical parameters. These meters are available for use in single phase and three phase circuits. The meters are available in tabletop models and panel mounting arrangements. Normally these meters are used in Electrical engineering laboratories for various measurements. The meters available are
1. Volt meters- analog /digital 2. Ammeters – analog / digital 3. Watt-meters – analog / digital 4. Phase sequence indicators 5. Tacho meters – contact type and photo reflective type 6. Reed type frequency meters 7. Phase meters. 8. Power factor metes.
This DC motor is integral, internally mounted cooling fan on the shaft. When the motor is running at rated speed the, fan provides the necessary cooling to give the assigned rating. When motors are required to start from zero speed and smoothly accelerate to the rated speed, these motors can be selected. If motors are to run below rated speed for long duration, either they have to be de-rated or can be forced cooled. The DC Generators are normally continuously rated and have to run at rated speeds only.
This requires DC rectifier source for its operation. The DC source to this is provided through a 3-4 point DC starter unit. Using this, several experiments on DC motor can be conducted. Depending on the experiment, you need appropriate meters, rheostats, switchgear are required. These motors are screen protected, with IP21/IP22 enclosures.
This is a typical setup for conducting experiments on two identical machines, which are mechanically coupled. This requires DC rectifier source of 15 A, for its operation. The DC source to this is provided through a 3-4 point DC starter unit. The coupled DC machine to this DC motor is used as generator. This generator may be loaded by drawing sufficient current using an external Loading rheostat. There by loading the DC motor. It is possible to evaluate the performance of this identical machines setup in several ways, for varied parameters.
This is an AC 3 ? synchronous alternator with, square path, 4 poles, and rotor wound stator excited type. This is screen protected IP22, with drip proof enclosure.
