Printer-friendly version
Glossary of terms you will come across during your Phase 2 training.


Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O
P | Q | R | S | T | U | V | W | X | Y | Z | ALL

Page:  1  2  3  4  5  6  (Next)
  ALL

H

:

H1 halogen lampThis is a halogen lamp. Because halogen lamps can operate at much higher temperatures, they are brighter (more powerful) than similar bulbs.

Take care when fitting these lamps, never handle the glass envelope directly. When supplied, the lamp is enclosed in packaging, designed to protect the glass envelope whilst it is being fitted.

:
H3 Halogen LampThis is a halogen lamp. Because halogen lamps can operate at much higher temperatures, they are brighter (more powerful) than similar bulbs.

Take care when fitting these lamps, never handle the glass envelope directly. When supplied, the lamp is enclosed in packaging, designed to protect the glass envelope whilst it is being fitted.

:
H4 HalogenThis is a halogen lamp. Because halogen lamps can operate at much higher temperatures, they are brighter (more powerful) than similar bulbs.

Take care when fitting these lamps, never handle the glass envelope directly. When supplied, the lamp is enclosed in packaging, designed to protect the glass envelope whilst it is being fitted.

:
H7 HalogenThis is a halogen lamp. Because halogen lamps can operate at much higher temperatures, they are brighter (more powerful) than similar bulbs.

Take care when fitting these lamps, never handle the glass envelope directly. When supplied, the lamp is enclosed in packaging, designed to protect the glass envelope whilst it is being fitted.

:

Hfe  refers to the gain of a transistor. As explained elsewhere on these pages, transistors are used mainly for switching and/or for amplification. The switching is the straight forward opening and closing of a circuit. Amplification refers to the action of a transistor whereby a small current flowing in the base/emitter (b/e) circuit causes a much larger current to flow in the collector emitter (c/e) circuit.

The ratio of times that the c/e current is larger than the b/e current is known as the gain. For example if the b/e current is 0.01mA and the c/e current is 1mA, then the gain is 100.

There are no units of measurement used when quoting gain, as it is a ratio. In this case the ratio is 100:1. In other words, the c/e current is 100 times greater than the b/e current.

You will find transistor gain listed in the datasheet of the transistor.

Keyword(s):
:

HacksawA saw used by cp fitters for cutting metal.

Keyword(s):
:

Plant vehicle electrical systems can only use direct current electricity (DC).

Electrical generators used on plant vehicles and machines produce alternating current (AC).

Before this AC can be used, it must first be rectified by using diodes to convert the AC to DC.

Depending on the number of diodes we use, and how we use them, we can get full wave rectification or half wave rectification.

Half wave rectification only makes use of the positive output of the generator. The negative output is not used.

Check out this course project which analyses full wave rectification and half wave rectification.


Contributor: Lorcan McGivney, CP Fitters, January to May, 2012.

Keyword(s):
:

HallThe Hall effect, named after the man who discovered it, describes the effect when a conductor carrying current is subjected to a magnetic field. Under these circumstances, a small voltage is generated at right angles to the direction of current flow. This is known as Hall voltage, Vh.

Keyword(s):
:

The Hall IC is an Integrated Circuit (IC) used in conjunction with Hall sensors. Hall voltages are very small, and ICs are used to amplify them before transmitting them on to an ECU.

Check here for more.

:

Ordinary lamps:

Typical headlamp bulbAn incandescent light bulb is a glass envelope filled with gas, with a wire filament inside it. When electricity is passed through the filament, it becomes  white hot. This is heat in the visible range. As the filament burns, byproducts evaporate off it and deposit on the inside of the glass tube. After a certain period in service, the filament either breaks or simply burns away completely, and the bulb burns out.

Halogen Lamps:

Typical halogen lampA halogen lamp is also an incandescent light, but the gas in the envelope is halogen and the filament is made of tungsten. Again, when the lamp is on, the filament gets white hot and begins to burn, but the halogen gas captures the evaporating tungsten and deposits it back on the filament. Thus a halogen light bulb will last quite a lot longer than the average incandescent bulb.

Advantages of Halogens:

  • They operate at much higher temperatures, so they burn brighter (they are more powerful).
  • They glow white hot in operation, at much higher temperatures than equivalent bulbs, so their light is much more natural looking. Conventional incandescent bulbs burn at much lower temperatures and give off more 'yellow' light.
  • Because the halogen gas deposits tungsten back on the filament as it burns, halogens last much longer than equivalent bulbs.


Page:  1  2  3  4  5  6  (Next)
  ALL