Chapter 7 THE PRICIPLE AND SYMBOL OF RELAY

The Relay consists of coil and contact. Coil wire windings is who gets an electric current, medium contact is a type of switch that movement depending on the weather or not there is an electric current in the coil. There are 2 types of Contact: Normally Open (the initial conditions before enabled open) and Normally Closed (the initial conditions before being activated close). Simply put the following working principles of the relay: when Coil get electrical energy (energized), the electromagnetic force will arise which will attract the armature that is berpegas, and the contact will close. 

In addition to functioning as an electronic component, the relay also functions as a system controller. So that the relay has two kinds of symbols used on:

• circuit (hardware),

• Program (software).

The following symbols are used:

In the data sheet, coil and contact information for separate. This causes each have a different specification difference as well. Note the following table.

Chapter 6 COMMUTATOR SYSTEM

Commutator serves as switch, namely to connect coil anchor briefly. Commutator form of a ring fitted on end coil anchor.If coil anchor rotatory; then ring sides to revolve.Because coil be in magnetic field, shall arise voltage commuting between sinusoidal.If coil has rotating half round, brush will close the aperture of a ring so that voltage be zero.Because ring spinning. , Then gap will open again and arising voltage again.If period voltage same with a period gyrations ring, voltage arises voltage direct current wave full.

 

The commutator serves as a rectifier mechanical, with sawn-off form a cooperation called comutation. Rectifier that produces better, then the commutator used there are many.Therefore every segment / hemisphere commutator no longer is partly, cylindrical form but it was shaped lempeng-lempeng.Among segments each plate / commutator guiler an insulating material.An insulator used determine class of machinery based on capability of temperature that arise in the machine.So beside as an insulator against electric insulators used to be able to heat.

Chapter 5 MULTIMETER

 

Multimeter is a measuring instrument used to measure voltage electricity, an electric current, and prisoner resistance. 

It is understanding multimeter in general, while in its development multimeter can still used to some function as measures temperature, inductance, frequency, and so on.There is also one who calls multimeter as avo meters, maybe it means a ( ampères ), v ( volt ), and o ( ohm ).

• Analog Multimeter is more widely used for everyday purposes, such as servicing the builders TV or computer using mostly analog type. Advantage is easy reading with a more simple look. While the drawback is low, so its accuracy for measurements requiring high-precision digital multimeter should use.

• Digital Multimeter features high accuracy, and usability is more when compared to analog multimeter. I.e. have an extra-additional units more thoroughly, and also a lot more measurement option, not limited to ampere, volt, ohm and only. Digital Multimeter is commonly used in research or work-work measure requiring high accuracy, but now it's a lot as well as workshops and service center computer that uses a digital multimeter. The drawback is difficult to monitor the unstable voltage. So when you perform a voltage measurement bobbing, preferably using an analog multimeter.

 

How To Measure DC Current (VDC) Use A Multimeter

How to measure DC Currents using a Multimeter is as follows:

• Set the Selector in the position of DCA.

• Select a scale measuring limit based on an estimate of the flow to be in check, for example: the flow in check around 100 Ma then position the scale at the boundary measure 250mA or 500 Ma.

• Note correctly limits the maximum current which is able to be measured by a multimeter because if it exceeds the limits of the fuse (fuse) on the multimeter will disconnect and the multimeter while it could not be used and fuse (fuse) should be replaced first.

• The installation of the probe multimeter is not equal to the voltage measurements DC and AC current measurement, because it means we cut off one of the connections the power supply to the load that will be checked arusnya, and then make the multimeter as conduit.

• Connect multimeter probes on the output voltage red () and power supply (-) probe on the input voltage () from the load/circuit to be checked using arusnya.

• Read the results of measurement on the multimeter.

How To Measure AC Voltage (VAC).

Using a Multimeter as it has in the DC voltage measurement, expect the voltage to be measured, place the term on a higher scale. In General only a multimeter can measure the frequency of the sine voltage between 30 Hz-30 KHz. measurement results is the effective voltage (Veff).

Here's how you do a measurement of AC voltage using multimeter:

• Set the Selector in the position of ACV.

•  Select a scale measuring limits based on estimates of the voltage to be in check, if the voltage in check about 12Volt then position the scale at the boundary measure 50V.

• To measure the unknown voltage magnitude then set limits measure at the highest position so that a multimeter is not damaged.

• Connect or attach probe multimeter voltage to the point to be checked. The installation probe multimeter could be reversed.

• Read the results of measurement on the multimeter.