Ammeter | Definition | Symbol | Formula | Type | Advantages | Uses

What is ammeter?


The meter uses for measuring the current is known as the instrument ammeter. The current is the flow of electrons whose unit is ampere. Hence the instrument which measures the flow of current in ampere is known as ampere meter or ammeter.

The ideal ammeter has zero internal resistance. But practically the ammeter has small internal resistance. The measuring range of the ammeter depends on the value of what resistance we have to set.

Symbolic representation:




Types of ammeter:


Following the type of ammeter regarding to construction:

  1. Permanent moving coil ammeter
  2. Moving iron ammeter
  3. Electro dynamometer ammeter
  4. Rectifier type ammeter 

1. Permanent moving coil ammeter


It is also called the PMMC instrument the conductors are placed between the pole of the percent magnet. When the current flows through the coil, it starts defecting. The deflection of the coil depends on the magnitude of current flows through it. This ammeter used only for the measurement of the direct current. 

2.  Moving coil ammeter

It is also called as the MI type of matter. The MI ammeter measure both the alternating and direct current. In this type of ammeter, the coil freely moves between the poles of a permanent magnet. When the current passes through the coil, it starts deflecting at a certain angle. The deflection of the coil is proportional to the current passes through the coil. 

3. Electro dynamometer ammeter


It is used for the measurement of both AC and DC. The accuracy of the instrument is high as compared to the permanent moving coil (PMMC) and Mvoinf coil (MI) instrument. The calibration of the instrument is the same both for AC and DC. If DC calibrations the instrument then without recalibration, it is used for AC 
measurement. 

4. Rectifier ammeter


It is used for measuring the alternating current. The instrument using the rectifying instrument which converts the direction of current and passes it to the PMMC instrument. Such a type of instrument is used for measuring the current in the communication circuit.

Application of ammeter:

  • The application of this device will range from school, colleges or to industry.
  • These are used to measure the current flow in the building to ensure that the flow is not too low or too high.
  • It is used with a thermocouple to check the temperature.
  • These current flowing through the coil produces the desire deflecting torque.
  • Electricians frequently use these devices to check the faults of the circuits in the building.
  • It is used in manufacturing and instrumentation companies to check the functionally of the devices.
  • This instrument is used to measure current in the circuit.
  • It is always connected series in the circuit and carries the current to be measure,
  • It is used with a thermocouple to check the temperature.
For detailed information>> Live use of an ammeter 


Advantages and disadvantages of ammeter

Advantages of ammeter:

  • It is strong, portable.
  • It does not dependent on the earth's magnetic field.
  • It could be made very accurate.
  • An ammeter is used to measure the magnitude of electric current in an electric circuit.

Disadvantages of ammeter:

  • It is heavy.
  • It needed multiple heavy meters to measure a different range of amperage.
  • It could not store data.

For detailed information>> Advantages and disadvantages of ammeter 

Difference between Step-up and Step-down transformer

The main key difference between step up and step down transformer is, step-up transformer raises the output voltage whereas the step-down transformer reduces the output current. Here this article gives information about the main key difference between step up and steps down transformer are listed below.

Definition of a step-down transformer:


A step-down transformer reduces the output voltage or in other words, converts high voltage, low current power into voltage, high current power. Our power circuit carries voltage from 230-110 v but the doorbell requires only 16v. Therefore the step-down transformer should be used to reduce the voltage from around 110v or the voltage from 220v to 16v. 

Definition of step-up transformer:


When the voltage is raised on the output side, That time the transformer is called the step-up transformer. In this transformer, the number of turns in the secondary winding is always greater than the turns in the primary winding because a high voltage is developed on the secondary side of a transformer. 

The main key difference between step up and step down transformer are listed below:


  • In Step-up transformer, the low voltage winding is the primary winding and high voltage winding is the secondary winding, while in step down transformer low voltage winding is the secondary winding.
  • When the output voltage is greater than its input voltage, it called a step-up transformer, while the step-down transformer output voltage is less. 
  • Step-up transformer extends the voltage from 220v-11kv or above, whereas step down transformer the voltage from 440-220v, 220-110v or 110-24v, 20v, 10v etc. 
  • In a step-up transformer, high voltage winding is the secondary winding, while the step-down transformer high voltage winding is primary winding.
  • In step-up current is low on the secondary winding, while in step down transformer current is high on the secondary winding. 
  • In step-up transformer mainly used in power plant, x-ray, machine, microwave, etc while in step down transformer mainly used in the doorbell, voltage converter, etc. 
  • In step-up transformer, the primary winding is made up of thick insulated copper wire and the secondary is made up of thin insulated copper wire while in step down transformer the output current is high so the thick insulated copper wire is used for making secondary winding. 
  • In a step-up transformer, the current and magnetic field is less developed in the secondary winding, and it is highly developed in the primary wiring. but in step down transformer voltage is low on secondary end thus the current and magnetic field high.
Explore more information:
  1. Difference between star delta connection
  2. Difference between a power transformer and distribution transformer 

Difference between switch and bridge

It is apparent that both bridges and switches in computer networks are of great importance. However, they differ from each other in a certain way. Here this article gives a information about the difference between switch and bridge to better understand this topic.

What is a bridge?


The bridge is known as the network bridge, it is a network interconnection device used to connect two or more local area networks. This bridge network is a responsible for network bridging, which is received and amplifies signals from a network cable and then sends them to the next table. It connects multiple networks of the network at the data link layer.

What is the switch?


A switch is a network device that is used for electrical or optical signal forwarding. It provides an exclusive signal path for any two network nodes and that access the switch. It has multiple ports, each with a bridge function that can be connected to a LAN or some high-performance server or uses workstations.

The main key difference between switch and bridge are listed below:

  • Switches have a higher no of ports while the bridge gave a lesser number of ports.
  • Packet forwarding in switches is performed using ASICS. Thus a switch is hardware-based, While the packet forwarding in the bridge is performed using the software. These bridges are software-based. Thus switch is hardware-based while the bridge is software-based.
  • The switch is generally used for connecting single topology while the bridge is generally used for connecting two different topologies. 
  • Switch segments a large LAN into many smaller segments, While the bridge segments a local area network into a couple of smaller segments.
  • Switch contains many ports for LAN connectivity, While the Bridge contains only a few ports for LAN connectivity. 
  • Switch contains many instances of spanning tree, Bridge contains only one instance of spanning tree. 
  • The switch has a buffer for each link connected to it which is missing in a buffer.
  • Methods
  •  of switching of a switch can be store and forward, cut through or fragment free, while the method of switching of a bridge is a store and forward. 
  • Switches are used to connect the work stations or computer systems. If there are 20 workstations connected to a switch then will be separate collision for each of the nodes while the bridges divide the collision domain into two parts. The bridge can create a collision domain but not the broadcast domain.
  • The switch performs error checking which is not done in the buffer, while the bridge does not perform for error checking.  
Explore more information:

Difference between batten and lead sheathed wiring

In batten wiring only used for serviceman etc. because of its high cost and heavy short circuit in case of leakage. while in lead sheathed wiring mainly used for workshop, public building, etc. Here this article give the information about the difference between batten wiring and lead sheathed wiring to batter understand this topic.

Definition of batten wiring:


This is when happening a single wire or some group of wire is laid over a wooden batten. These wires are held to the batten for using a brass clip and spaced at an interval of 10 cm for horizontal runs and 15 cm for vertical runs.


Definition of lead sheathed wiring:


The lead sheath is earthed at each and every junction to provide a path to ground for the leakage current. They are fixed means that of metal clips on wooden battens. The wiring system is very expensive. It is suitable for low voltage applications.

Difference between lead sheathed wiring and batten wiring:

  • Batten wiring is a low cost, while the lead sheathed wiring is costly.
  • Both have low voltage up to 250V.
  • Both have a long life.
  • In batten wiring protection against fire is fair, while the lead sheathed wiring the protection ain't fire is good.
  • Dampness protection is good for both wirings.
  • Appearance is good for batten wiring, while the lead sheathed wiring appearance is fair.
  • General reliability is good for batten wiring, while the lead sheathed wiring fairly good.
  • No point that can be wired per day by a wireman with a mate is 4, while in lead sheathed wiring is three.
  • Alteration or addition to the existing wiring to very difficult, while in lead sheathed wiring most difficult. 
  • Material required for batten wiring is teak wooden batten, lead, sheathed cable, round board, screw, clip, clipboard, wooden while in lead sheathed wiring material required for VIR or PVC cable, Huck, screw, IC boxes, IC bands, saddles or pipe hooks, IC socket, and screw, etc.  
  • In batten wiring only used for serviceman etc. because of its high cost and heavy short circuit in case of leakage. while in lead sheathed wiring mainly used for workshop, public building, etc. 

Advantages and disadvantages of repeater

A repeater is a network device that regenerates the incoming signal gives strengthen to transmit it to the next devices which are connected without losing any actual data or the information. To know more about repeater let us discuss the advantages and disadvantages of a repeater,


Advantages of the repeater:
  • Repeaters can extend a network's total distance.
  • A repeater is simple to connect.
  • Repeaters do not seriously affect network performance.
  • It is cost-effective.
  • Certain repeaters can connect networks using different physical media.
  • It has the ability to boost or strengthen the digital to retransmit.
  • Some reporters can connect networks using various physical media.

Disadvantages of the repeater:

  • Repeater are unable to reduce network traffic.
  • Limitation in the number of repeaters.
  • It cannot connect difference network architectures. 
  • It does not segment the network.
  • Repeaters do not separate the device in the collision domain.
  • Most of the repeaters on a network produce noise on the wire and increase the possibility of packet collisions.
  • A device that is separated only by a repeater is part of the same collision domain.

Category of ammeter

Application of ammeter

Meter is an instrument that can measure a particular quantity. As we know that the unit of current is ampere. An ammeter is ampere meter which measures ampere value. Ampere is the unit of the current so an ammeter is a meter or an instrument that measures current. Here this article gives information about the advantages and disadvantages of the ammeter to better understand this topic.

Uses of ammeter:

  • The application of this device will range from school to industry.
  • These are used to measure the current flow in the building to ensure that the flow is not too low or too high.
  • It is used with a thermocouple to check the temperature.
  • These current flowing through the coil produces the desire deflecting torque.
  • Electricians frequently use these devices to check the faults of the circuits in the building.
  • It is used in manufacturing and instrumentation companies to check the functionally of the devices.
  • This instrument is used to measure current in the circuit.
  • It is always connected series in the circuit and carries the current to be measure,
  • It is used with a thermocouple to check the temperature.
  • When PMMC is used as an ammeter, except for a very small current range, the moving coil is connected across a suitable low resistance in shunt, so that only a small part of the main current flow through the coil of the device.
  • The shunt consists of a number of thin plates made up of alloy metal, which is usually magnetic and has a low-temperature coefficient of resistance, fixed between two massive blocks of copper. A resistor of the same alloy is also placed in series with the coil which reduces due to temperature variation,