Electricity and Electronic

Rocker switch and Slide switch

2012-05-24T21:01:00.002+07:00

Rocker switchRocker switch works the same way as a toggle switch, where there is a lever that can be pressed up and down. Lever of the rocker switches are usually called to rocker lever, shaped like an electric bell button.Generally there are two numbers on the rocker lever, numbers 1 and 0. When the lever is pressed on number 1, indicating that the switch in the On position, and when the lever

Rotary switch

2012-05-23T23:53:00.004+07:00

Rotary switch is a switch type which is operated by way of played. These switches are used to connect one line to one other line, among several lines that already exist. Often, several pieces of rotary switch is used in the same unit.Examples of common use rotary switch is serves to select a range of measurements on an AVO meter or a multimeter, or to choose a power supply voltage. This type of

Press switch, PTM switch and PTB switch

2012-05-22T23:37:00.002+07:00

Press switch is a type of switch that is operated by pressing a button. There are two types of press switch, ie push to make (PTM) switch and push to break (PTB) switch.Most of the press switch is a kind of the PTM switch. By pressing a button PTM switch, the contacts will be depressed until the switch is closed and touch each other. While by pressing a button switch type of PTB switch, the

Toggle switch, SPST switch and SPDT switch

2012-05-21T21:40:00.002+07:00

Toggle switch is the simplest form of switch, operated by a toggle lever that can be pressed up and down. According to the convention, position of the lever downwards to indicate OFF conditions or switch contacts is disconnected, and position of the lever upwards to indicate ON conditions or switch contacts are connected.Toggle switch have two terminal tag, which indicates that switch have a

The Switch, On condition and Off condition

2012-05-11T20:44:00.004+07:00

The switch is a device used to control the flow of electrical current into the circuit. In the previous discussion about electric current, the electrical current will only flow in a closed circuit. So as to create a current to flow or not, we can use the switch.Current flows when the switch contacts touch each other. In this state, the switch is said to be closed or made contact.Current can not

Reflections, Diffusion and Refraction

2012-04-22T10:17:00.002+07:00

ReflectionWhenever light falls onto surface, some of it is absorbed and the remainder is either reflected or transmitted. If the surface is opaque and smoothly polished, the specularly reflected light leaves the surface at the same angle as is arrived (as a billiard ball striking a cushion), and by suitably shaping the surface it is possible to redirect the light in any desired direction (e.g.

Lighting and common terms used in lighting design

2012-04-16T21:21:00.001+07:00

Virtually all buildings have electric lighting which serves two purpose. It help us to recognise objects quickly and in sufficient detail to learn all we need to know about them, and it contributes to making buildings safe and pleasant place in which to work or take part in other activities.There must always be enough light to make object visible but other factors are no less important. The

Application for Thyristor: Excitation of synchronous motor

2012-04-14T21:22:00.005+07:00

In the past the overload torque requirement has been met by using a large frame size than necessary to meet full load torque requirements, the torque being proportional to the product of the AC supply voltage and the DC field produced by the excitation current.With thyristor control of excitation current it is possible to use a smaller frame size for a given horse power rating and arrange to

Passive components and active components

2012-04-13T21:36:00.002+07:00

Electronic components are divided into two types, namely passive components and active components. Passive component is a component that can not lead to increase in the electric power circuit, examples of passive components are resistors, capacitors, and inductors.While the active component is a component that can lead to increase in the electric power circuit, examples of active component is

Gain transistor

2012-04-10T23:23:00.003+07:00

Gain transistor or the acquisition of the current generated by the transistor, commonly referred to as the small signal current gain, while the magnitude of the gain is written with symbols HFE. This gain value is determined when the transistor is made, and with a very diverse range. For example, type BC548 NPN transistor has a range between 110 and 800.Under conditions of saturation, the gain is

Cut off condition and saturated condition of transistors

2012-04-02T21:03:00.005+07:00

In the switch circuit, transistor sometimes be in the inactive state, where there is no any current flows through it. These conditions is called transistor's cut off condition.Figure A shows the state of the transistor in a cut off conditionAt other times when the transistor is in the fully active state, where there are only a relatively small potential difference between the emitter and

Thyristors or SCR (Silicon Controlled Rectifier)

2012-03-29T23:53:00.009+07:00

The Thyristors is a semiconductor switch either of the pnpn or npnp type, whose bi-stable action depends on regenerative internal feedback. Figure at the left is symbol of thyristor, where A is anoda terminal, C is cathode terminal and G is gate terminal.The four layer device is usually silicon although germanium has been used. Devices with the two endmost layers only connected to external

Photo Electric Devices

2012-03-27T20:35:00.002+07:00

There's a lot of photo electric devices, such as photo-cell relays, photoelectric switch units, silicon photo-electric cells and silicon blue cell.Photo-cell relays. Basic component of photo-cell relay is an integral light activated switch. It combines a silicon planar photo diode with integrated circuit on a single substrate to provide a highly sensitive photo electric device. Operation is such

Resistivity of any material

2012-03-24T10:09:00.007+07:00

The resistivity of any material is the resistance of a piece of material having unit lenght and unit sectional area. The symbol is ρ and the unit is the Ohm meter. The resistivity of a material is not usually constant but depends on the temperature.Table below shows the resistivity (with its reciprocal, conductivity) of the more usual metals and alloysTable Resistivity of any material at 20 °C

Power supply circuit with variable voltage

2012-03-02T21:32:00.002+07:00

By using a transformer without ct, a bridge rectifier circuit system, and rotary switch, we can create a power supply for electronic equipment with voltage range from 3 V, 4.5 V, 6 V, 7.5 V, 9 V, to 12 V.Add component such a rocker switch or a slide switch as the main switch, and put one LED as an indicator tool.Power supply circuit with variable voltage as shown belowClick to enlargeComponents

Diode bridge rectifier circuit

2012-02-25T21:31:00.003+07:00

Diode bridge rectifier's circuit is a full-wave rectifier circuit that uses four diodes, and connected as a bridge. Unlike the full-wave rectifier discussion in previous article, where the circuit uses two diodes, this time is full-wave rectifier circuit with four diodes.Beside different from amounts of diodes, other difference lies in use of a transformer, which transformer used in the bridge

Transistor as a switch

2012-02-23T20:20:00.004+07:00

One function of transistor most commonly used in the electronics world is as a switch. To find out how transistor as a switch, we do experiments on the following circuit.Switch (S1) condition in Off state or open, there is no voltage source attached to the base terminal of transistor, so that there will be no current flowing in the circuit, in other words, the lamp will not light.Switch (S1)

How transistors work

2012-02-20T20:31:00.003+07:00

If there is no external voltage is connected to transistor, then there is no current flowing in a circuit, in other words all the electrical current equal to zero. So to use a transistor, we need to link in such a way, to obtain a current flow that we want.Circuit below is an example of how the NPN transistors workwhere:Emitter terminal is a negative polarityCollector terminal has a few volts

Determine terminals and type of transistor using analog multimeter

2012-02-15T23:45:00.005+07:00

Almost all of analogue multimeter or AVO meter (Ampere, Volt and Ohm meter, as shown in the figure below), can use to determine terminals (base, emitter, and collector) and type of transistor (PNP or NPN). On this configuration, turn the knob multimeter's position on Ohm meter test or at symbol Ω.We take an example to be measured is transistor BJT type FCS9015, which is quite widely use. We

How to determine terminals and type of transistor using digital multimeter?

2012-02-14T21:31:00.004+07:00

Requirement to determine terminals (base, emitter, and collector) and type (PNP or NPN) transistor using an AVO meter or multimeter or digital multitester, is multitester must have a diode test feature. Diode test feature is usually denoted by symbol of a diode, as shown in multitester's picture below.We take an example to be measured is transistor type C945, which is quite widely use. We learned

Transistor, bipolar and unipolar

2012-02-01T21:25:00.001+07:00

Transistor is an electronic component semiconductor, has ability to control the effective resistance by controlling the main signal (voltage and amperage) from a distance.There are two types of transistors, namely a bipolar junction transistor or abbreviated by BJT, such as PNP and NPN, and unipolar transistor junction transistor or abbreviated by UJT, such as FET and MOSFET.Transistors made from

Produce a pure wave DC from rectifier circuit

2012-01-30T23:50:00.004+07:00

DC output generated by a rectifier circuit, not a wave of pure DC, but the waveform up and down or pulsing. These waves can not be used to distribute electronic circuits.Process of flattening the pulsing waves of rectifier circuit, it can be done by connecting in parallel a large value of filter capacitor to output DC, as in the circuit belowThe capacitor used is usually electrolytic capacitors (

Full-wave rectifier circuit

2012-01-29T12:42:00.003+07:00

Current output generated by half-wave rectifier circuit, is only worth half input cycle. This means that half of the input power is wasted.Rectifier would be better, when using two diodes in series. Consider the circuit belowOn positive cycle and negative cycle of the AC waveform, given a forward bias diode. Current flows through two diodes to the load and returned to the transformer through the

Half-wave rectifier circuit

2011-11-05T21:54:00.003+07:00

One of most important use of diodes based on the ability of diode to conduct current in only one direction. When the diode is mounted on an alternating current or AC current, then the sine wave is converted into unidirectional wave or DC current.Watch what happens to the circuit belowElectrical current is supplied to the circuit is an alternating current generated by a transformer. During the

AC (Alternating Current) and DC (Direct Current)

2011-11-05T21:24:00.002+07:00

Voltage at the positive terminal of a battery will last a constantly, until the cells ran out of charge. If we plot a graph illustrating voltage changes with time, the graph for a new battery as follows:Tangible graphs above is horizontal straight line. The graph shows that battery voltage will stay constant at a value of 6 V.If we connect battery to a lamp, we can use a multimeter to measure the