Written on February 25, 2011 at 5:34 pm by Power Tool Team

Pin End Scroll

Filed under Power Tools no comments

Pin End Scroll
We have found the best prices for you! See below for more!

12 Hobby Scroll Saw Blades 3 inch for Dremel Moto Shop
Paypal

US $12.50

12 Scroll Saw Blades 5 inch 132mm pin pinned for Dremel Ryobi
Paypal

US $12.50

12 Scroll Saw Blades 3 inch 76mm for Dremel Moto Shop Emco Lux Hobby 450
Paypal

US $12.50

Intelligent Lighting

History

There are many patents dating back from 1906 when Edmund Sohlberg of Kansas City. The lantern used a carbon-arc bulb and was operated not by motors or any form of electronics, but by cords that were operated manually to control pan, tilt and zoom.

1925 saw the first use of electrical motors being used to move the fixture, and with it the beam position, by Herbet F.King. Patent number: 1,680,685. In 1936 patent number 2,054,224 was granted to a similar device, but where the pan and tilt were controlled by means of joystick as opposed to switches. From this point on until 1969, various other inventors made similar lights and improved on the technology, but with no major breakthroughs. During this period, Centuary Lighting (now Strand) started retailing such units specially made to order, retro fitted onto any of their existing lanterns up to 750 watts to control pan and tilt.

George Izenour made the next breakthrough in 1969 with the first ever fixture to use a mirror on the end of a ellipsoidal to redirect the beam of light remotely. In 1969 Jules Fisher, from Casa Manana area theatre in Texas saw the invention and use of 12 PAR 64 lanterns with 120watt, 12volts lamps fitted, 360 degrees of pan and 270 degrees of tilt, a standard that lasted util the 1990s. This lamp was also known as the 'Mac-Spot'

In Bristol, 1968 progress was also being made, mainly for use in live music. Peter Wynne Wilson refers to the use of 1kw profiles, with slides onto which gobos printed, inserted from a reel just like on a slide projector. The fixtures also had an iris, a multiple coloured gel wheel. These lights were also fitted with mirrors and made for a impressive light show for a Pink Floyd Gig in London. Another fixture known as the 'Cycklops' was also used for music in the USA, although it was very limited in terms of capabilities with only pan and tilt functions and at 1.2meters long and weighing in at 97kg including the ballest, they were heavy and cumbersome.

In 1980 after the invention of Dichronic colour filters by Jim Bornhurst in early 1980 the dawn of the VariLite moving head became reality, starting with the VL0, demonstrated to Genisis in the summer. It also used one of the first lighting desks with a digital core and this enabled lighting states to be programed in. The demo to Genusis compromised of the VL0 hung in the centre of an old barn. Changing colour and moving from one corner of the room to another, the four executed steps were simple, but impressive to anyone who had not seen the technology before.

Genisis was later to order 55 VLO1's to use in their next chain of gigs across the UK. The lights were supplied with a VL series 100 console which had 32 channels , five 1802 processors and a dramatic improvement of the first console which was very simple, had an external processing unit. The VL1 also demonstrated the first ever use of a XLR cable in a lighting-control application, though DMX was never sent through it.

In 1985 the first ever moving head was produced by Summa Technologies to use the DMX protocoll, which at the time was rare and was among many other formatts including DIN8, AMX, D54 and the protocols other companies such as Tasco, VariLite, High End and Coemar were producing. It also looked recognisable, a fixture that wouldn't look out of place in a theatre. The Summa HTI had a 150watt HTI bulb, 2 colour wheels, a Gobo wheel, a mechanical dimmer and zoom functions. For the time, they had packed more features into it than anybody else before.

In 1987 ClayPacky began producing the first recognisable scanner, the Golden Scan. It utilised stepper motors instead of servos and used a HMI 575 lamp, bright and with a far more uniform beam brightness. Tbis was followed by the Intellabeam in 1989, also realsed by High End, who, at the time were the Distributors for Clay Paky and Belliveau.

In the 1990s the future came closer with Martin, a Danish Company producing Fog Machines. They manufactured a line of scanners known as the Roboscans, with a variety of different specs for different users. Their range started with the 218, for the small venue and went up in brightness and features through 518, 812, 918 and 1200Pro units. Martin also invented a whole new range of Moving Heads including the Mac250, the Mac250+, Mac300, Mac500, Mac600, Mac700, Mac1200 and more recently the Mac2000 and MacIII. Martin Mac's are popular in most rental situations and are also a great compromise between the cheaper manufactured products and the top end luminaires such as a High End DL2.

The future promises many great things as the concept of digital lighting, a bright LCD or DLP projector mounted in a yoke or moving head type fixture with an integrated media server will allow for millions of colour choices, endless libraries of gobos, image and video projections to take place. The DL1 and DL2 by High End Systems (Barco) and Publitec Beamover.

Features

Several intelligent lights in use at a concert. Note the white beams they produce

An automated light, properly called a luminaire, fixture (or sometimes moving head), is a versatile and multi-function instrument designed to replace multiple conventional, non-moving lights. Depending on the venue and application, automated luminaires can be a versatile and economical addition to a stock of traditional lights because, with proper programming, they can swiftly alter many aspects of their optics, changing the ersonality of the light very quickly. Lighting is typically pre-programmed and played back using only simple commands, although moving heads can be controlled ive if the operator is sufficiently experienced.

Most moving heads have all or some of the features, each feature is set to a channel number, such as this:

Pan

Tilt

Fine Pan

Fine Tilt

Dimmer

Shutter

Gobo1 Select

Gobo1 Rotation

Gobo2 Select

Gobo2 Rotation

Gobo3 Select

Colour1

Cyan

Magenta

Yellow

Prism 3,5,9facet

Prism Rotation

Effects Wheel

Gobo Animation Wheel

Iris

Lamp Shut off, fixture reset

Remote patching channel

Control

Moving lights are controlled in many ways. Usually the fixtures are connected to a Lighting control console, which outputs a control signal. This control signal sends data to the fixture usually in one of three ways: Analogue (which has largely been phased out), DMX (which is the industry standard control protocol), or Ethernet Control (which is still in development). The fixture then takes this signal and translates it into internal signals which are sent to the many stepper motors located inside.

XLR connectors, the most common method of controlling moving heads. Note that these are 3-pin XLR connectors, which are used by some manufacturers, rather than the 5-pin, which specified by the USITT DMX-512 Standard.

The vast majority of moving heads are controlled using the DMX protocol, usually using dedicated twisted pair, shielded cable with 5-pin XLR connectors at the ends. Each fixture is assigned a block of DMX channels in one of the venue's DMX universes (a self-contained set of cables and fixtures which can operate a maximum of 512 individual channels). The central lighting desk transmits data on these channels which the intelligent fixture interprets as value settings for each of its many variables, including color, pattern, focus, prism, pan (horizontal swing), tilt (vertical swing), rotation speed, and animation.

Since moving heads did not attain prominence until DMX's predecessor, analogue, had passed the zenith of its popularity, very few moving heads use analogue control (this is also due to crippling restrictions on bandwidth, data transfer speeds and potential inaccuracy). Some of the most modern intelligent fixtures use RJ-45 or Ethernet cabling for data transfer, due to the increased bandwidth available to control increasingly complicated effects. Using the new Ethernet technology, control surfaces are now able to control a much larger array of automated fixtures. Because many devices can be connected to a single RJ-45 network, these devices have the ability to not only listen to a control signal from a lighting control board, but have the ability to transmit information back to the control board and other entities on the network. Now, it is possible for a fixture to self-diagnose any problems, announce itself on a network, or accept setting changes from any place on the network, making obsolete older versions of the system that only had one central brain, the lighting control board. Because RJ-45 (and equivalent technologies) use bidirectional digital communication, bit-checking abilities allow for lighting control networks to safely operate devices that can interfere with human saftey (pyrotechnic devices, rigging mechanisms, etc.).

Moving lights are programmed using a fixture box in ETC light boards

Moving lights are much more difficult to program than their analogue cousins because they have more attributes per fixture that must be controlled. A simple conventional lighting fixture uses only one channel of control per unit: intensity. Everything else that the light must do is preset by human hands (color, position, focus, etc.) An automated lighting fixture can have as many as 30 of these control channels. A slew of products are available on the market to allow operators and programmers to easily control all of these channels on multiple fixtures. Lighting boards are still the most common control mechanism, but many programmers use computer software to do the job. Software is now available that provides a rendered preview of the output produced by the rig once fixtures are connected to the program or console. This allows programmers to work on their show before ever entering the theater and know what to expect when the lights are connected to their controller. These products usually feature some method of converting a computer's USB output to a DMX output.

The latest generation of moving heads are integrating digital projection capabilities, creating a real convergence between lighting and video projection. These new generation of heads do not only require intensity, position and focus control, but will require video content control as well.

Construction

Intelligent fixtures usually employ compact arc lamps as light sources. They use servo motors or, more commonly, stepper motors connected to mechanical and optical internal devices to manipulate the light before it emerges from the fixture's front lens. Examples of such internal devices are:

Mechanical dimming shutters used to vary the intensity of the light output. Mechanical dimmers are usually a specially designed disk or a mechanical shutter. Shutters with high speed stepper motors can be used to create strobe effects.

Color wheels with dichroic color filters used to change the color of the beam.

Variable, incremental Cyan, Magenta and Yellow color-mixing filters to vary beam color via subtractive color mixing. Using this method, a much wider range of colors can be created than is possible using single color filters.

Automated lens trains used to zoom and focus the beam; irises are used to change the size of the beam. Some fixtures have as many as 10 independently controlled prisms and lenses to focus and shape the beam .

Pattern wheels with gobos and gate shutters to change the shape of the beam or project images. Some fixtures have motors to rotate the gobo in its housing to create spinning effects, or use their complicated lens systems to achieve the same effect.

Automated framing shutters to further shape the beam and control unwanted spill.

These fixtures also use motors to enable physical movement of the light beam by either:

Pivoting an automated mirror which reflects the beam along X & Y axes, or

Attaching the entire fixture lens train to a yoke with motorized pan & tilt

Note that fixtures which use the former method are not technically oving heads, since the light source itself does not move. However, the term oving head is used interchangeably throughout this article.

Usage

5 Moving Yokes Lighting up a Mirror Ball

Intelligent lights (now commonly referred to as automated), can be used wherever there is a need for powerful lighting which must be capable of rapid and extreme changes of mood and effects. Moving heads would, therefore, be inappropriate in a setting which does not require strong lighting (such as a home) or where the uality of the light required does not vary excessively (although it may need to be very strong for a venue like a stadium). Naturally, there are exceptions to this rule, most notably the use of large numbers of moving heads for international sporting events, such as the Commonwealth Games or Olympic Games, where many thousands of separate automated fixtures are often used to light the opening and closing ceremonies. The 2008 Summer Olympics, in Beijing, had a rig of around 2,300 intelligent fixtures which is "the largest single automated lighting system ever assembled for a single event"

Usually, however, the use of intelligent lights is confined to theatre, concerts and nightclubs, where the versatility of these fixtures can be utilised to its best extent. In these applications, the uses of fixtures can be informally grouped into two categories: active and passive (although these are not standardised terms).

Passive use of automated lighting involves utilizing their versatility to perform tasks which would otherwise require many conventional lights to accomplish. For example, six to eight moving heads can create a textured blue ight effect on the stage floor while applying amber light to the actors during one scene - this can create a sensation of dusk or night. At the flick of a switch, the fixture can change to an animated red ire effect for the next scene. Attempting this transition with traditional lighting fixtures could require as many as thirty instruments. In this circumstance, the automated fixtures are not doing anything that could not be achieved using conventional fixtures, but they dramatically reduce the number of lights needed in a rig. Other features of automated fixtures, such as rotating gobos, are also possible with conventional fixtures, but are much easier to produce with intelligent fixtures.

A martin mac 250 entour (profile - top) and mac 250 wash) wash - bottom).

Active use of automated lights, suggests that the luminaire is used to perform tasks which would otherwise require human involvement, or be simply impossible with conventional fixtures. For instance, a number of moving heads producing tightly-focused, pure white beams straight down onto the stage will produce a fantastic effect reminiscent of searchlights from a helicopter (especially if a smoke machine or hazer is used to make the beams visible). To recreate such an effect without intelligent lights would require at least one human operator seated directly above the stage with a followspot, which would generally be considered to be too expensive for such a small effect.

Moving head fixtures are often divided into spot and wash lights. They vary in use and functions but many companies offer profile and wash variants of the same model of light. Profile lights generally contain features like gobos and prisms, whereas wash lights have simpler optics and a wider beam aperture resulting in wider beam angle, which may be altered by internal lenses or rost effects. Wash lights are more likely to have CMY colour mixing although it is common for high-end spot lights to have such features too. Spot units are generally used for their beam effect (usually through smoke or haze) and the ability to project texture, whereas wash lights tend to be used for providing a stage wash.

A martin mac 250 entour (profile - top) and mac 250 wash) wash - bottom). Notice the difference in beam characteristics caused by the gobo of the entour and the wider beam angle of the wash.

Debate

Not all the light fixtures that have movement can be defined as intelligent. Basic club lighting is not controllable other than basic on and off. This lack of features makes them just a small step above a conventional Stage lighting instrument.

Moving mirrors are faster than moving head fixtures. However moving heads are visually more interesting, and have a far larger range of movement. The movement from mirror lights tends to be rectilinear, because the centre of movement for both axis is usually in the same place, while one axis of a moving head luminaire describes a circle (usually called "pan") and the other (the "tilt") changes the diameter of the circular movement. In early luminaires a pseudo rotating gobo effect could be achieved by moving the tilt in line with the other axis and then moving the pan from end stop to end stop.

References

^ http://www.mts.net/~william5/history/hol.htm - scroll down to "Early Automated Lighting" ~1970

^ DMX512 Control Protocol Information - Connectors and Cables

^ Cadena, Richard (2006). Automated Lighting. Focal Press. pp. 5658. ISBN 978-0-240-80703-4.

^ LeMaitre FireCtrl Device,An example pyrotechnic control device that can accept RJ-45 control.

^ Barco | Barco digital moving luminaire tears down boundaries between projection and lighting

^ Cadena, Richard (2006). Automated Lighting. Focal Press. pp. 253254. ISBN 978-0-240-80703-4.

^ Product - MAC 2000 Profile

^ Casestory - XVIII Commonwealth Games, Melbourne, Australia

^ MA Lighting On Beijing Olympics 2008

^ Martin Lights Beijing Summer Olympic Games

See also

Stage lighting instrument

External links

Moving-lights - repository of technical info

v d e

Stagecraft

Theatrical scenery

(Scene shop)

Fields

Set construction Scenic painting Scenic design Technical direction

Hardware

Flats Platforms Curtains Fly system

Stage lighting

Fields

Lighting design Lighting technician Master electrician

Hardware

Gobo Color gel Batten Barn doors Color scroller Cyclorama Stage pin connector Top hat Theatrical fog

Instruments

Ellipsoidal reflector spotlight Intelligent lighting Fresnel lantern Beam projector Scoop Striplight Parabolic aluminized reflector light

Other Fields

Sound design Theatrical property Costume design Video design

Categories: Stage lighting
About the Author

I am a professional writer from China Chemicals Products, which contains a great deal of information about lr1130 button cell , multi purpose charger, welcome to visit!

A horizontal force (magnitude P) is applied. If P = 75 lb, what is the tension in the cable?

A uniform 100-lb beam is held in a vertical position by a pin at its lower end and a cable at its upper end. A horizontal force (magnitude P) acts as shown in the figure**. If P = 75 lb, what is the tension in the cable?

The answer is 54 lb. How was this derived?
** Here is the link to the figure:

http://www.scribd.com/doc/18103178/Serway-Physic-Chapter-12

It is problem number 4 (scroll down), and it is on the left hand side.

When an object has no rotational acceleration, the net torque on it is zero. That means (in this problem) the clockwise torque exactly cancels the counter-clockwise torque.

You can measure the torque around any axis; but in this problem it's convenient to measure it about the pin on the bottom.

Clockwise torque:
P * 5 ft

Counter-clockwise torque:
T * 8 ft * sin(60)

(The "sin(60)" arises from the fact that you have to account for the direction that the tension is acting. In general, you multiply by the sine of the angle between the radius vector and the force vector.)

Clockwise torque = Counter-clockwise torque:
P * 5 ft = T * 8 ft * sin(60)

Solve for "T" and you get 54 lbs.

[Note: kuiperbelt2003's answer is also correct; it's just another way of looking at it. Note that "cos(30)" is the same as "sin(60)" ]

Rotary Attachment