Monthly Archives: September 2014

Special Note

Your display will vary over time, starting out as a wide, undefined glow with purplish and orange disks and eventually forming a defined purple tornado-like vortex extending to the length of the container. This change is due to the pressure increasing and is a func­tion of leakage and internal impurities. The system, properly processed, should be active for up to months before repumping is required.

This chapter shows how to construct a novelty product that provides a bizarre special-effect light display. It is fashioned after the Star Wars lightsaber (see Figure 21-1) and uses a recently patented phe­nomenon involving’ traveling plasma” (our patent #5,089,745). Total control of this display effect is accomplished by simple grip contract on the saber’s handle. No switch is used in any way. Energized plasma (an electrically ignited gas giving off visible light) travels up the saber, illuminating its length as it moves. The effect is greatly enhanced in darkness and is quite dramatic when properly controlled by the user. This gives the effect of a controllable length of visible light appearing to emanate from the handle of the device and continues out into space. A striking visual display now results when operated at low light levels.

Expect to spend $25 to $35 for this awesome, attention-getting display project. Instructions are detailed with all the specialized parts, the printed cir­cuit board (PCB), and the actual plasma tube avail­able from www. amazingLcom. Tlie parts list is included in Table 21-1 at the end of the chapter.

Assembly Instructions

This project will require a properly working Tesla driver, as described in Chapter 17.

Obtain a 1-gallon pickle jar or the equivalent with a brass – or tin-plated metal cap for the display con­tainer, as shown in Figures 20-2 and 20-3. The display container must have a provision for depressurizing and then being permanently sealed. Again, this metal cover of a pickle jar makes an excellent choice because a piece of copper capillary can be directly soldered to it. forming a good, vacuum-tight seal and allowing pinching off for sealing. Should the display container require repumping, the pinched capillary may be easily reopened for reconnection to the vac­uum system.

The display container may be mounted on a suit­able stand that houses the generator beneath, resem­bling a water cooler. Refer to the figures for final assembly and pump down instructions.

Assembly Instructions

Note that the penny stiffens up the thin metal cover to provide a sturdy mounting point for the capillary tubing.

Automotive Cover preparation:

vacuum hose 1. Drill a 125" hole in the center of a copper penny and in the jar cover.

2. Throughly clean the penny and cover to a bare shiny surface.

3 Obtain a propene torch and solder the tube to the penny and to the jar cover as shown. Try not to bum the jar seal. Verify that the solder completely seals this point as any leaks will prevent operation.

4. Throughly clean the jar and let it dry. Put in microwave and "nuke’1 for 30 seconds.

5. Apply vacuum grease to the jar seal and tightly screw on the cap.

6. Unit is ready to pump down.

Assembly Instructions

as this point must support the high voltage and high-frequency energy for this setup.

3. Slide copper capillary into appropriate section of vacuum hose.

4. Allow to pump down to limit of system-should be below tOO millitorrs.

5. Bleed off to.5 Ton and apply power, noting rarefied air glowing a purplish pnk.

6. Disconnect from vacuum system and pinch off section of rubber hose as shown.

7. Connect power supply output now to copper tube on cap and reapply power, noting a well-defined tornado – shaped discharge extending the full length of jar Display is visible under normal lighting but should be quite spectacular in the dark See note below

NOTE – Display may vary with temperature, proximity to other objects, grounding, and, of course, pressure of air inside. Many display variations are possible and experimentation is suggested.

Figure 20-2 Assembly and pump dam

Connection is made to copper tube by a slip fit to vacuum hose

Assembly Instructions

Jar is sealed via a small washer pinching the folded rubber hose. This method provides an excellent temporary seal that is easily removed for repumping etc.

Caution: Jar is under a high vacuum and should be placed in a meshed bag to contain flying shards of glass rf used in public.

Output from power supply can cause a moderately peinful shock or bum. It is not injurious or life threatening due to low current and high frequency.

DANGER: Jar is under a high vacuum and will implode violently if broken.

Assembly Instructions

Insulating plate-use glass or plastic. Dry wood will wor4 but might leech off energy. You may also support it on a glass mixing bowl.

Use a metal plate by grounding, ungrounding, or attaching various lengths of wire etc. for best results.

Operation

t. Place an approx. 6 x 6" piece of metal on a larger piece of glass or other insulating material.

2. Place jar as shown on metal plate. Do not ground for now

3. Verify proper operation of power supply as shown on instructions.

4. Connect up green grounding ieed to a positive earth ground. Failure to do this will result in improper operation

5. Connect output lead to copper capillary tube exiting the jar cover.

6. Rotate power control full CCW and turn on power switch.

7. Rotate power control until you get desired effect that should be a pink column of energized plasma resembling a tornado

Bnng hand near jar and note attraction of display.

This demonstrates the capacitive effect produced by proximily of two conductive objects. The high – frequency current now wants to flow between these points that form a capacitive reactance.

Hold a fluorescent lamp near the jar and note it lighting! This demonstrates the radiative effects of the energized plasma and provides an interesting science project.

If you are fortunate enough to have access to a vacuum pump, experiments with different pressures can yield some real interesting results.

Adjust power control knob for maximum display. Note a peak in adjustment.

Do not leave on for extended periods of time until you check for heating of supply and jar.

Fi g и re 20-3 Plasma tornado jar setup

Application and Operation

The display is inside a glass enclosure and resembles a tornado shape of glowing and swirling plasma. It dances and jumps to anything brought near it and is highly visible, even in normal, fluorescent lighting. This sensitivity to any external capacity creates many bizarre and seemingly striking effects. The plasma also can light up a fluorescent lamp when brought near the glass enclosure without any wires or connec­tions of any kind. This feature demonstrates the highly radiative properties of the plasma field and serves as an excellent science fair project or a unique conversation piece.

Theory of Operation

An evacuated glass comainer is sealed and pumped to.5 to 2 Torrs of pressure. A metal cap seals the con-

tainer and serves as an electrode for charging the remaining thin gas mixture. The voltage applied to the cap is at a potential of 10 to 20 thousand volts and is at a high frequency of approximately 25 kHz. The capacitive effect of the thin gas causes a current to flow, creating the plasma discharges. One may visual­ize the device in the following manner: A capacitor is formed by the conductive gas inside the container forming one plate, the glass envelope being the insu­lating dielectric and the outer air serving as the other plate. Any conducting object brought near the con­tainer now only enhances this effect and appears to draw the plasma arc to the point of contact.

The vacuum will vary along with the physical parameters of the container and can be adjusted to enhance the type of discharge desired. A pressure where the plasma discharges are most defined may be critical. Increases will create a broken, wispy effect, whereas a further decrease will broaden the discharge and eventually form striations as a series of weird, orange disks. Any weird effects are possible from changing pressure, power frequencies, and voltage.

The effect of where the conduction of a gas peaks at a certain pressure is known as the Townsend effect and becomes an important factor in the design of vacuum systems where medium – to high-voltages are encountered. The device as described does not use any gas other than the existing atmosphere rarefied by evacuation. Other colors and effects are limitless when the builder chooses to charge the unit with other gases or combinations of pressures.

Project Description

The described device is intended for display pur­poses, novelty decorations, and special effects, as well as an educational science fair project demonstrating plasma that is controlled electrically and magneti­cally. Special materials treated by a controlled plasma beam can also be realized.

Plasma is often considered lo be the fourth state of matter. It consists of atoms that are ionized and

demonstrates peculiar effects unlike the other three forms of matter.

Columns of pinkish and purplish plasma are attracted to external influences such as fingers and other objects when placed on or near the display con­tainer. These columns of plasma light span the entire length of the display container, dancing and writhing with a tornado-like effect. Balls of plasma and fingers are created and controlled by simply touching the container. This effect cannot be effectively or justifi­ably described in words and can only be appreciated when actually observed.

The device is low powered, high frequency, and high voltage, producing the necessary parameters for obtaining the described plasma effect. This generator utilizes conventional electrified circuitry, consisting of a transistor switching the ferrite core of a high-volt­age resonant transformer (similar to a TV flyback). Power for the transistors is obtained from a simple step-down transformer and rectifier combination.

Testing the Circuit

To test the circuit, follow these steps (see Figure 19-2):

1. Set the bottom of the ladder elements to no more than 4a of an inch separation and tem­porarily short circuit the ladder elements with a clip lead. Preset the trimpots R4 and RIO to midrange (12 o’clock).

2. Connect an oscilliscope to TP1 and TP2. If you do not have a scope and your assembly is correct, you may assume the circuit is cor­rectly functioning if the following measure­ments are read.

3. Obtain a 40-watt lightbulb used as a ballast and an isolated source of 115 volts-alternating

current (VAC), preferably with a adjustable voltage transformer (variac) and a current- reading meter. A suggested circuit is described in Chapter 8 (see Figure 8-3).

Rotate R19 full clockwise (CW) and quickly adjust R4 to read a period of 40 microseconds (usee) (25 kHz). Turn R9 back full counter­clockwise (CCW).

4. Turn off the power and remove the short across the ladder elements, as directed in step

l. Turn on the power and advance R19 in a CW direction, noting an arc that forms and attempts to rise up the ladder. Switch out the ballast, noting the full action of the plasma arc rising and breaking at around 3 inches and repeating. Check that the fan is fully on and measure 12 volts-direci current (VDC) across the leads,

5. Observe the line current, noting that it rises to around 1 to 2 amps as the arc rises and breaks at the ladder top.

6. Firmly grab a metal object and contact one of the ladder elements. The unit should quickly

Testing the Circuit

Figure 19-3 Wiring diagram

shut down. Note that R4 may be adjusted CW 7. Even though the circuit is intended for contin – to increase shutdown sensitivity or to full uous use, the project as described should not

CCW to disable. The normal setting is at be left on unattended,

midrange.

Testing the Circuit

Allow access to FAULT and ADJ trimpots.

Figure 19-4 Bottom view of parts lavout

Testing the Circuit

Figure 19-Б Top view of parts layout

Table 19-1 Jacob’s ladder parts

Ref. # Rl

R2,3

R4

R5.ll

R6,7

R8

RIO

R30

R9

R19/SW1

Rx

C2

C3

C4

C8

CIO, И

C12

СЗО

Dl,2,3,4

D5

D6

D30

Qty. Description

100-ohm, ‘/4-watt resistor (br-blk-br)

2 18K, 3-watt metal oxide (mox) resistor

2K vertical trimpot

2 IK, ‘A-watt resistor (br-blk-red)

2 15-ohms, ‘/4-watt resistor (br-grn-blk)

Ю-ohm, 3-watt mox resistor

10K vertical trimpot

30-ohm, 3-watt mox resistor

lOOK, l/4-watt resistor (br-blk-yel)

IOK potentiometer and 115 VAC switch

In-rush current limiter #CL1V0

10 mfd/25-volt vertical electrolytic capacitor

.01 mfd/100-volt plastic capacitor

.1 mfd/600-volt metalized polypropylene capacitor

2 1.5 mfd/250-volt metalized polypropylene

capacitor

.0015 mfd/600-volt metalized polypropylene capacitor

.47 mfd/50-volt plastic capacitor

2 220 to 330 mfd/200-volt vertical

electrolytic capacitor

.01 mfd/1 Kv disc capacitor

100 mfd/25-vo! t vertical electrolytic capacitor

4 1N5408 1 Kv, 3-amp rectifier

1N4937 1 Kv fast-switching diode

1N914 silicon general purpose diode

1N40011-amp rectifier diode

Ref. #

IC1

Ql,2 2

SCR

Zl,2 2

PCI

THERMOl 2 SWNYLON 2

Qty.

COl

Tl

WR24

WR20

WR20KV 5 feet BASE

LADDERS 2

BLOCKS 2 FEET 4

TYE12

SCRW6 8

WASH6 2 SCRW4X1 2

SCRW8X.5 4

Description

IR2153 dual in-line package driver

IRF450 metal-oxiile-semiconductor field effect transistors (MOSFETs)

Sensitive gate silicon-controlled rectifier #EC103D

6-volt 1-watt zener diodes #IN4735

PCB and wire as shown in Figure 19-3 #PCLINE

Insulating thermo pads for Ql and Q2

6-32 X ‘/2-inch nylon screws and metal nuts

Panel-mount fuse holder and 3-amp slow-blow fuse

Three-wire #18 power cord

High-voltage ferrite switching transformer, #JACKT1

#24 red and black pieces of hookup wire

#20 red and black pieces of hookup wire

20 Kv silicon high-voltage wire

6 x 9 x ‘/4 finished plywood or Lexan, fabricated as required

18 x ‘/г x.05 stainless steel, fabricated as shown

I ‘/4 x 1 x 3/4 PVC or Teflon blocks

I X 2 wooden dowels or plastic

12-inch tie wrap tor securing Tl

#6 X 3Ai-inch blunt sheet metal screws

#6 X V2-inch washers

#4-44 X ‘/2-inch screw and nuts for attaching the assembly board

#8 X ‘/2-inch wood screws for attaching feet pieces

#6 solder lugs

This project provides a simple yet quite spectacular display of various lorms of electrical plasma (see Fig­ure 20-1). The medium used is safe, ordinary, rarefied air pumped down to a rough vacuum of approxi­mately Ч2 millimeters (which is measured in Torr, which is a measure of pressure equal to 1 millimeter of mercury). The plasma display takes on various forms from a well-defined, multivortcx swirling tor­nado to a column of orange saucer-shaped disks. Hand proximity to the container produces an interac­tive mechanism where the tornado can be controlled both in position, movement, and intensity.

Testing the Circuit

Testing the Circuit

Figure 20-1 Plasma tornado enclosure jar

The low-cost construction includes the use of a 1- gallon glass pickle jar as the plasma display vessel. A wide-mouthed jar is preferred with a brass cap that will allow the soldering of the necessary fittings. The electrical input is supplied by the high-frequency, high-voltage Tesla project described in Chapter 17. ^‘Solid-State Tesla Coil.” You will need access to a vacuum pump usually found in most high school sci­ence labs that will pump down the air. A pumped – down jar—one that is processed with a vacuum—is available from ama7ingl. c0m. Properly processed, the display will last up to a year.

Tr£veling-Plasma Jacob’s Ladder

This popular electrical display saw great fame in ihe old Frankenstein horror movies of the 1930s. A con­tinuous traveling arc of electrical plasma climbs a metal ladder, expanding and eventually evaporating into space (see Figure 19-1). At thal moment, the arc reinitiates at the bottom of the ladder and now con­tinually repeats the cycle. It must be noted that these older displays required dangerous and lethal amounts of electricity to obtain the desired results. This property often discouraged their use in public places.

This project generates a plasma arc over 3 inches long that travels a ladder height of nearly 24 inches. It rapidly recycles and contains an arc power adjust­ment

Not only is this a rewarding and energetic display, any shock hazard is greatly reduced by the use of our patented safety shutdown circuitry. Any contact to the ladder elements results in immediate circuit shut­down, avoiding any shock. Even if the shutdown were disabled, contact would only cause a minor burn as the output energy is at a high frequency.

Most parts are readily available and are listed in Table 19-1 at the end of the chapter. Those that are specialized, including a printed circuit board (PCB), may be obtained through www. amazingl. com.

Expect to spend $50 to $75 to complete the project as shown.

Origin

The Bible tells the story of Jacob’s dream about a ladder that extended from Earth to heaven. Jacob, the son of Isaac, was the father of the founders of the 12 tribes of Israel. Among sailors, however, a Jacob’s ladder is a long rope ladder that is hung over the side of a ship so the harbor pilot can climb aboard.

Basic Description

The power supply for this project forms electric arcs across two diverging stainless steel strips (LAD­DER). The 16-inch-long strips are mounted on insu­lating blocks to eliminate possible leakage. The stainless steel strips are separated by about a quarter – inch at their bases and diverge to a distance of about 3 to 4 inches at their upper ends.

The strips form a gap across the secondary wind­ing of the output transformer. After power is turned on, the air dielectric breaks down due to the almost short-circuit state across the lower end of the gap, and an electric arc is formed. As the arc heats up, thermal convection causes the arc to rise up the V – shaped ladder. As the plasma arc ascends the ladder,

its length increases, thereby increasing the arc’s dynamic resistance and thus increasing power con­sumption and heat. This causes the arc to stretch as it rises, and it extinguishes when it reaches the top of the ladder. When this happens, the transformer out­put momentarily exists in an open circuit state until the breakdown of the air dielectric produces another arc at the base of the ladder and the sequence repeats.

Tr£veling-Plasma Jacob's Ladder

Figure 19-1 Jacobs ladder plasma machine

Circuit Descriptions

We suggest you refer to the circuit description sec­tions in Chapter 8, “Handheld Burning C02 Gas Laser,” as this project is very similiar, with the excep­tion of the added safety shutdown circuit shown in Figure 19-2. This circuit detects any abnormal ground currents that would be produced by accidental con­tact to one of the ladder elements. Current now flows through the resistor divider (R5 and R9) and biases diode (D6) into conduction. A rectified voltage is now developed across capacitor (C8) and trimpoi (R4). The trimpot sets the trip point of the silicon – controlled crowbar switch, shorting out the supply voltage to IC1 and turning off the power circuit.

Rssembly Steps

To begin the project, follow these steps:

1. Study Figures 19-3 and 19-4 showing the power board. Assemble as shown, adding the safety shutdown components shown in Figure 19-2.The added parts are Rl, R4, R5. R9, C8, C12, D6, and SCR and are included on the parts list in this chapter.

2. Assemble the heat sink bracket as shown in Figure 8-8 (Chapter 8).

3. Assemble the main power board shown in Figure 19-3.

4. Finally, assemble everything as shown in Fig­ures 19-4 and 19-5, and read all special notes and options.

Tr£veling-Plasma Jacob's Ladder

5. Verify all the wiring for the solder shorts, the correct components, the polarity of parts where noted, and the general overall quality of the assembly.