88-108 MHz Voltage Controlled Oscilator for PLL Controller

This Circuit will explain the PLL unit and the VCO (Voltage Controlled Oscillator) which will create the FM modulated RF signal up to 400mW. the schematic to follow my function description. The main oscillator is based around the transistor Q1. This oscillator is called Colpitts oscillator and it is voltage controlled to achieve FM frequency modulation) and PLL control.

Q1 should be a HF transistor to work well, but in this case I have used a cheap and common BC817 transistor which works great. The oscillator needs a LC tank to oscillate properly. In this case the LC tank consist of L1 with the varicap D1 and the two capacitor (C4, C5) at the base-emitter of the transistor. The value of C1 will set the VCO range.

The large value of C1 the wider will the VCO range be. Since the capacitance of the varicap (D1) is dependent of the voltage over it, the capacitance will change with changed voltage. When the voltage change, so will the oscillating frequency. In this way you achieve a VCO function. You can use many different varicap diod to get it working. In my case I use a varicap (SMV1251) which has a wide range 3-55pF to secure the VCO range (88 to 108MHz).

Inside the dashed blue box you will find the audio modulation unit. This unit also include a second varicap (D2). This varicap is biased with a DC voltage about 3-4 volt DC. This varcap is also included in the LC tank by a capacitor (C2) of 3.3pF. The input audio will passes the capacitor (C15) and be added to the DC voltage. Since the input audio voltage change in amplitude, the total voltage over the varicap (D2) will also change. As an effect of this the capacitance will change and so will the LC tank frequency.

You have a Frequency Modulation of the carrier signal. The modulation depth is set by the input amplitude. The signal should be around 1Vpp. Just connect the audio to negative side of C15. Now you wonder why I don't use the first varicap (D1) to modulate the signal? I could do that if the frequency would be fixed, but in this project the frequency range is 88 to 108MHz.

If you look at the varicap curve to the left of the schematic. You can easily see that the relative capacitance change more at lower voltage than it does at higher voltage. Imagine I use an audio signal with constant amplitude. If I would modulated the (D1) varicap with this amplitude the modulation depth would differ depending on the voltage over the varicap (D1). Remember that the voltage over varicap (D1) is about 0V at 88MHz and +5V at 108MHz. By use two varicap (D1) and (D2) I get the same modulation depth from 88 to 108MHz.

Now, look at the right of the LMX2322 circuit and you find the reference frequency oscillator VCTCXO. This oscillator is based on a very accurate VCTCXO (Voltage Controlled Temperature controlled Crystal Oscillator) at 16.8MHz. Pin 1 is the calibration input. The voltage here should be 2.5 Volt. The performance of the VCTCXO crystal in this construction is so good that you do not need to make any reference tuning.

A small portion of the VCO energy is feed back to the PLL circuit through resistor (R4) and (C16). The PLL will then use the VCO frequency to regulate the tuning voltage. At pin 5 of LMX2322 you will find a PLL filter to form the (Vtune) which is the regulating voltage of the VCO. The PLL try to regulate the (Vtune) so the VCO oscillator frequency is locked to desired frequency. You will also find the TP (test Point) here.

The last part we haven't discussed is the RF power amplifier (Q2). Some energy from the VCO is taped by (C6) to the base of the (Q2). Q2 should be a RF transistor to obtain best RF amplification. To use a BC817 here will work, but not good.

The emitter resistor (R12 and R16) set the current through this transistor and with R12, R16 = 100 ohm and +9V power supply you will easy have 150mW of output power into 50 ohm load. You can lower the resistors (R12, R16) to get high power, but please don't overload this poor transistor, it will be hot and burn up… Current consumption of VCO unit = 60 mA @ 9V.

Printed Circuit Board (PCB.pdf)
This is how the real board should look when you are going to solder the components.
It is a board made for surface mounted components, so the cuppar is on the top layer.

Parts List
100 = R7, R12, R16
330 = R4
1k = R1, R2, R3, R10
3.3k = R11
10k = R5, R6, R14, R17
20k = R13
43k = R9
100k = R8, R15
3.3pF = C2, C16
15pF = C4, C6
22pF = C5
1nF = C1, C3, C8, C17, C22, C23
100nF = C7, C9, C11, C12, C13, C14, C19, C20
2.2uF = C15, C18
220uF = C10, C21
L1 = 3 turns diam 6.5mm (Everything from 6 to 7 mm will work good!)
L2, L3, L4 = 10uH
D1, D2 = SMV1251
Q1 = BC817-25
Q2 = BFG193
X1 = 16.800 MHz VCTCXO Reference oscillator
V1 = 78L05
IC1 = LMX2322

Source

Diode Data Sheet

Diode Data Sheet

– Provides maximum ratings, electrical characteristics, mechanical data, graphs of parameters, etc. for electrical device in use.

– Several parameters are seen in a data sheet for diodes:

Maximum ratings

i) V_RRM: (Peak repetitive reverse voltage).

– Maximum reverse peak voltage that can be applied repetitively across the diode.

ii) V_R: (DC blocking voltage)

– Maximum reverse dc voltage that can be applied across the diode.

iii) V_RSM: (Nonrepetitive peak reverse voltage)

– Maximum reverse peak value of nonrepetitive voltage that can be applied across diode.

iv) I_O: (Average rectified forward current)

– Maximum average value of a 60Hz rectified forward current.

v) I_FSM: (Nonrepetitive peak surge current)

– Maximum peak value of nonrepetitive (one cycle) forward surge current.

– A graph for different temperatures is generally available.

vi) T_A:

– Ambient temperature.

vii) T_J:

– Operating junction temperature range.

viii) T_stg:

– Storage junction temperature range.

Electrical Characteristics

i) v_F: Instantaneous voltage across the forward-biased diode when forward current is 1 A at 25^oC. Shown generally shown by a graph.

ii) V_F(avg): Maximum forward voltage drop averaged over a full cycle.

iii) I_R: Maximum current when diode is reverse-biased.

iv) I_R(avg): Maximum reverse current averaged over one cycle (when reverse-biased with an ac voltage).

Robust Engineering "Innovative Product design Ideas"

Plastic Egg Cartons "-: Reusable "crack free eggs" cartons

If we look at the market places, we would be able to find products like this already from Fall Harvest Products™ Plastic cartons.

But this product is disposable and is a vacuum formed blistering plastic product.

We think we can design better product than this existing product design, through improved design ideas.

1. We are aiming to reuse these plastic egg trays so that it would be an environmental friendly plastic product.

2. We are aiming to use clear engineering plastics and latest mould design techniques so that we can utilize our design skills to redesign differently and focus to protect the eggs from being damaged. (During loading, unloading and its transport)

3. We can manufacture this product from clear plastics so that we can have a close look from the outside so that the eggs can be seen without being opened.

4. We can additionally supply colourful products, which will differentiate the different egg manufacturers. It will help shoppers recognize their product so easily.

5. Finally we can design a new "Plastic egg crate" to carry bulky egg trays.

Plastic Mould design Principles 1. Mould cooling

A competent mould designer must have a through knowledge of the Engineering principles behind the mould designs.

First of all we will try to cover the Mould cooling

One fundamental principle of Plastic Injection moulding is that hot material enters the mould, where it cools rapidly to a temperature at which it solidifies sufficiently to retain the shape of the part. The temperature of the mould is therefore very important as it governs a portion of the overall moulding cycle. Also ttemperature control of moulds directly proposal to the properties of the thermoplastic injection moulded parts as well.

While the melt flows more freely in a hot mould, a greater cooling period is required before the solidified moulding can be ejected. Again if the melt solidifies too quickly in a cold mould it may not be able to reach the extremities of the cavity. So therefore a compromise between the two extremes must be accepted to obtain the optimum moulding cycle.

Today most of the people are willing to do their Plastic mould design/Manufacture in China. The reason behind this decision was the term "cheep" in other words when they do they can save huge money in $$$. Now I will show you what could be the dangers would come behind this cheep tooling process and what could be the subsequent long term problems will arise and would effect the quality of the Injection moulded plastic part and eventually the final risk involved to collapse the whole engineering systems.

Swimming Pool Solar Heat Control Circuit

This is a swimming pool solar heating panel pump control. The circuit in below is use an external thermistor that is attached to the solar panel in a manner that will allow it to sense heat generated by direct exposure to the sun. This circuit is controlled by IC TC621-C. This is the figure of the circuit.


A thermistor with a resistance of about 100 kΩ at 25°C should be selected. One such thermistor is the ACW-027 from Ketema, which can be clamped around a pipe in the solar panel. This circuit will energize the pump when the sun is heating the panels and turn off the pump when the sky is cloudy or the sun goes down. To prevent rapid cycling of the pump during partly cloudy conditions, the hysteresis is set for a relatively wide (20°F) span. Providing low thermal impedance between the thermistor assembly and the solar panel will also prevent rapid pump cycling by adding the solar panel’s thermal time constant to the hysteresis. To select the set point resistors, consult the thermistor data sheet for the thermistor’s value at the desired temperature. For example, assume that we want the pump to turn on (high set point) at 100°F and turn off (low set point) at 80°F. [Schematic diagram source: Microchip Technology, Inc].

Stepper Motor Controller

This is one kind of design control circuit. This a motor stepper controller circuit that is a simple, low cost, and accurate position controls. Stepper motor can be driven by circuit mounted close to the motor, and controlled by a remote control circuit through long cable. The interesting thing of this circuit is that the power for both motor and the driver circuit is carried over two wires, the same wires that carry the control signal. This is the figure of the circuit.


LMC555 CMOS timer integrated circuit (IC1) generates 200 microsecond pulses to step the motor and control its speed. The speed of the motor can be changed by changing the frequency of this pulse, R1 variable resistor is provided for this purpose. At the output of IC1 (pin 3), a negative going clock pulse drive the gate of IRL530N (Q1) power FET that momentarily turns OFF and disconnects the driver board from ground. This power interruption sends a signal to the motor driver to step the motor. The rotation direction is controlled by the polarity of the voltage applied to the driver circuit through interconnect lines L1 and L2. MPSA05 Bipolar NPN transistor Q2 and MPSA55 PNP transistors Q3 and Q4 invert the pulse from pin 3, pull the drain of Q1 UP when it is OFF. Toggle switch S1 sets its direction by switching polarity. Pushbutton S2 starts and stops the motor by turning the clock on and off.

Parts
C1 – .47 MFD 35 volt tantalum
C2 – 1000 MFD 35 volt electrolytic
C3 – .1 MFD 50 volt metalized film
C4 – .001 MFD 50 volt metalized film
C5 – 100 MFD 16 volt electrolytic
R1 – 5MEG potentiometer
R2, R8, R10 – 100K 1/8 watt 5%
R3 – .56K 1/8 watt 5%
R4, R5, R7 – 10K 1/8 watt 5%
R6 – 2K 1/8 watt 5%
R9 – 4.7K 1/8 watt 5%
Q1 – MPSA05 NPN transistor
Q2, Q3 – MPSA55 PNP transistor
Q4, Q5, Q6, Q7, Q8 – IRL530N Hexfet
D1, D2, D3 – 1N914 silicon diode
D4, D5 – 1N4752 zener diode
D6 – 1N4004 rectifier
BR1 - 2 AMP 400 volt bridge rectifier
IC1 – LMC555 CMOS timer
IC2, IC5 – 78L05 5 volt regulator
IC3 – CD4013 dual D flip flop
IC4 – CD4070 quad exclusive or
S1 – momentary N/O push button switch
S2 – double pole double throw toggle switch
T1 – DC or AC adapter transformer to match motor
IC socket – 1 eight pin
IC sockets – 2 fourteen pin
Terminal blocks – 2 two position
M1, M2 – two phase unipolar 24 volts

activate the application

AdaptivEnergy RLP energy-harvesting beam

Typical effect of decreasing temperature, which reduces the effective storage capacity of many lithium batteries
Efficient energy collection is vital to making energy harvesting a viable technology. To complement the high output of the RLP, AdaptivEnergy engineers have designed electronics to efficiently capture and store the energy produced. While the circuit design is proprietary, the efficiency of the design can be traced to the use of ultra-low-power components. The Joule-Thief offers several options for energy storage, including capacitors and lithium batteries. A version with the latest thin-film lithium-ion battery technology is being evaluated. The goal is to provide appropriate energy storage means for the customer's application.

Paradigm Shifts
It is hard to determine if it is the emergence of new technology or the evolution of application requirements that brings change. In both cases, end users often must alter the way they look at operating requirements and opportunities. For example, powering sensors with energy harvested from ambient sources requires a paradigm shift in how electronic devices are powered. If continuous operation of an electronic device is not necessary, then the average power output of an energy-harvesting device is not the metric of concern. AdaptivEnergy encourages customers to "think joules, not watts" because the important criterion is the amount of energy needed to perform the customer's task, not how much power can be generated. Once this is understood and the amount of energy collected by the device is known, it becomes a simple task to determine how much data can be collected and how often a transmission can be made.

The same technology that allows for power-autonomous sensing devices also ushers in new application opportunities. In this case, wireless sensors are being deployed with increasing frequency where the installation of wiring is not a viable option. A good example of this is the use of sensors to monitor the health of machinery. Wireless sensors allow more machinery parameters to be monitored simply because their installation and maintenance requirements are relatively palatable compared with their hard-wired cousins. In addition, they make it possible to avoid unscheduled downtime, to limit maintenance only to times when it is required, and to reduce operating and maintenance costs.

Another application of energy harvesting and wireless sensors is structural health monitoring, a hot topic after the collapse of the I-35W Mississippi River Bridge in Minneapolis, Minnesota, and the collapse of the construction cranes in New York City. This application genre also includes aircraft. In this industry, when the expense of installation, maintenance, and the fuel required to carry the additional weight of the wiring is taken into consideration, the cost per foot of wire can approach $2000. Furthermore, in many aircraft applications, the sensors are simply too difficult to reach to change the batteries. And even if it were possible to reach the sensors, the cost of the labor to purchase, store, and change a battery far exceeds the cost of the battery itself. The ultimate goal of aircraft manufacturers is to embed sensors in the structures during fabrication. Automobile manufacturers face similar challenges, particularly with the high price of gasoline. The increase in fuel efficiency enabled by reductions in vehicle weight has led auto manufacturers to consider wireless sensors and switches to help reduce wiring harness weight in vehicles, which now weighs up to 500 pounds.


Structural health monitoring applications, such as the collapse of this New York City crane, are well served by energy-harvesting-enabled wireless sensors
Predictions and Trends
These tactical paradigm shifts herald broader changes. For example, perennial futurist Ray Kurzweil predicts a day when "ambient intelligence" will enhance the way people interact with their environment. In Kurzweil's world, sensors will be scattered around like dust to sense everything in the environment and provide feedback to improve our lives and safety. This multitude of sensors will likely not be battery powered. With microcontrollers and sensors in more and more simple electronic devices (e.g., refrigerators, washing machines, and coffeemakers), it's beginning to look as if Kurzweil's vision of the future may be correct. The smart home of the near future will be filled with sensors, and it's anticipated that energy-harvesting devices that can power the sensors will play an important role in their future.

Another fact that Kurzweil likes to point out is that technology improvements tend to follow exponential trends. For example, Moore's law predicts the number of transistors on an integrated circuit will double every two years. This prediction proved accurate, and the trend continues to this day. Similar exponential shifts can be expected in the size and power requirements of electronics, where devices become increasingly smaller and require less and less energy to operate. Paralleling these shifts, the capacity, or energy density, of energy-harvesting technology, such as AdaptivEnergy's Joule-Thief, will increase exponentially. When the impacts of these trends converge, a new world of energy-harvesting-powered electronic devices will become feasible and more and more self-powered electronic applications will become part of our daily lives.

Today's Products
The commercialization of AdaptivEnergy's energy-harvesting technology (see sidebar "Test Drive Power Harvesting") began with a project for In-Q-Tel, the venture capital arm of the U.S. intelligence community, but AdaptivEnergy's customers are now exploring a wide range of applications for the Joule-Thief beyond wireless sensing. In fact, the technology is being evaluated in applications as diverse as machinery and structural health monitoring, vehicular sensing and switching, and asset tracking.

As power requirements for electronics continue to decrease exponentially, and the power output of energy-harvesting devices continues to increase exponentially, more and more self-powered electronic applications will become feasible. A question often asked is "Can you power my cell phone or MP3 player?" Maybe not today, but that day is coming, and it may not be too far in the future. In the meantime, powering wireless sensors appears to be an ideal application for energy harvesting.

Test Drive Power Harvesting
For evaluation purposes, AdaptivEnergy offers a vibration-powered Wireless Sensor Demonstration Kit (Figure 6) in which five sensing devices, a Texas Instruments MSP430 microcontroller, and a Texas Instruments CC2500 wireless radio are powered entirely by a vibration source. All the sensor data can be transmitted approximately once per second with the included vibration source, or every five seconds with vibration amplitudes in the tens of mg. For those unfamiliar with vibration amplitudes, this represents a vibration that is barely perceptible to human touch. If longer durations between transmissions can be tolerated, it's possible to power the device with imperceptible vibrations.


Figure 6. AdaptivEnergy Wireless Sensor Demonstration Kit
To specify energy-harvesting material for a wireless node, you need to know the frequency and amplitude of the source vibration, the energy required to perform a transmission, and how often a transmission must be performed.


RLP and Joule-Thief are registered trademarks and trademarks, respectively, of AdaptivEnergy LLC.

Electrifying Sexual Toys

Since the inception of electronics, its popularity has become very significant and has become the driving force for the development of more inventions. These innovations have given manufacturers an idea to capitalise on the importance of electronics to manipulate a mechanical device, which can give people satisfaction out of it.
Nowadays, the integration of electronics in adult entertainment has given a new meaning for pleasure. Due to the insistent demand of people for such products, a lot of electronic gadgets have been produced in order to fulfil his or her desires. Sexual devices are now being sold in the market with various designs that should suit the wildest fantasies of both sexes.
Manual or automatic sexual toys have been introduced in certain shops in order to satisfy the different needs of people from all over the world. Everybody over 18 years old can now enjoy the pleasure that these devices can provide. You just have to be responsible in keeping it, so that little kids may not play with them while you are not around.

How to use Pro mould PTC software efficiently and effectively?

Robust engineering Pty Ltd Australia has had answers based on with their 15 years Pro Engineer Pro Mould design experience.

I, as a user, can say that ”Pro Mould design software “is the number one software in the world when it is used especially to split any complex Plastic Mould design tasks within a allocated time frame.

In the past, I have used Uni-Graphics however there is no way any software could come close to Pro Mould design.

If any one feels that releasing such a statement by me was wrong, then I am calling you "Assumed that you as a smart UG user" to come forward and challenge me through a bench mark test and try to prove that I was wrong.

You can't do that. it is an open challenge towards all UG users within Australia and across the world.

Well Time has already been gone and I feel that UG users are all now got my message very clearly.

Now it is my time as a Pro engineer user to show Others that we can do it better than others.

To promote my Robust engineering basic website as well to promote Pro engineer CAD software to the other CAD users, I am ready to carry out this mission.

So I have decided to show you one natural product which is available in the market. I am going to model that product with two colour material moulding. Mould design, which I am going to create in front of you would show you the technique involved behind the two color moulding.

Honestly I have never ever seen anything like this product in the market so far. I just thought, if anyone see this type of product,please let me know so that I can change it to design something else.

If any one would like to follow my design idea(s), it would be great. You will be successful. No doubt about that.

But remember I am just showing this to you to let you learn Pro engineer mould module methodology very clearly.So depending on your material and injection pressure sizes would be changed.

As a Innovative Product designer, Innovative Mould designer, Moulding expert and off course skillful CNC programmer you have to decide that parameters.

Would I be able to tell this design would be an innovative concept or thinking to this particular design problems? Definitely "not". I have just thought that we can think of better ways to produce any existing product by imagining differently.

But I will let you to decide this matter yourself. This is the way I think. Robust engineering will think. So It is a another different thinking approach which will change the current existing products into smart looking products.

"we don't just design the tools, we create the cost effective innovative tools" this is my company vision statement.

As a company initiator, I would like to use my full ability to show everyone the above sentences are true.


Robust engineering found this random plastic product as its design sample to demonstrate a two colour mould design.


This product won the Australian International GN Awards recently.


This product has been already got TPE rubber over moulding feature. So it is a good one for our mold design exercise.


In order to do this exercise, I need to remodel this product through Pro engineer CAD systems.


I assumed without breaking its patented copy right issues, I would be able to do so..


Eveready Dolphin Mk5 Lantern



























http://www.designawards.com.au/application_detail.jsp?applicationID=2385

Product Description and Principal Function(s)

The new Dolphin Mk5 Lantern is a redesign (evolution) of the successful Dolphin Lantern. It retains all of the key aspects of the original Dolphin Lanterns with the benefits of enhanced features such as the integrated adjustable stand, large textured ergonomic handle, co-moulded tough rubber lens ring, dual facet reflector and modern contemporary styling.

How to use Mastip Hot runner System's selection Guide efficiently?

Overview and Detail analysis


Mastip manifold systems and nozzle selection guide.


As an experienced hot runner manifold designer and Mastip hot runner nozzle user and former Application engineer Mastip Technology New Zelaand, supported technically so many Mastip hot runner assisted plastic tools around the world, I would be able to talk about this brillient systems in detail.


I am absolutly sure that next time you can use this system more efficiently.



Mastip Standard Hot Runner Configuration:

http://www.mastip.com/Downloads/SystemSelectionGuide_V2.05.pdf

Page 4 shows the general hot half mould layout

Important points when it come to design your hot runner Plastic tools..
1.
As you can see,hot runner manifold is placed between fixed side clamping plate and Manifold bolster plate or intermediate plate.
2.
Cavity plate machined according with nozzle pocket dimensions

Imporatnt aspects during maching.

Machining the hot runner nozzle sealing area is important.It should bear in mind that boring to the required diameter should allow the nozzle to slide during its expansion so need perfect sliding fit.

It is so eacy to cut the nozzle insulation pockets with CNC assisted ball nose end mill operation. Even tiny gate could be done through similar way with 0.5 -1mm ball nose. or Most of the people spark erode this gate.

We have to make sure that gate surface finish is so important therefore should not have any maching marks as this will lead to pressure loss along the gate area . Good surface finish will assist a better Plastic filling and gate control to obtain better cycle time.

During the operation, nozzle will expand along its axis.So very important to make sure the overall dimension between the gate end to top of the nozzle head pocket surface. This length is Nozzle length + Thermal expansion. Most probably tip side will expand more than its head.

During thermal expansion,we should make sure nozzle has sliding fit and nozzle tip will be in its exact spot during injection.

Manifold also will expand side ways during operation so that we must make sure nozzles top surfaces must have a perfect match (no gap between the nozzle and the manifold).
3.
During the machine start up, we need to heat the manifold and need to do the necessary purging opearation also during color change time purging opeartion is absolutely essential.This all can be done very easily if we design the Mould as per shown on the technical diagram .So that we can separate the cavity plate and manifold plate while mold is on the machine.

Also this will assist the molder to quickly change the dead nozzle heater or Thermocouple, while the mould is on the machine.

4.
Wiring grooves should be machined between these two plates and need a proper clamps so that nozzle heater and Thermocouple wires want be damaged during assembly or opeartion.


5. If there is a thermocouple placed under the manifold surface to monitor the heat, depending on your nozzle selection & manifold design, nozzle head dimensions should be checked and if that is too small than thermocouple overall height then it should be placed within a machined groove to avoid damge during manaifold assembly.

5.
Same with the manifold sprue bush heater wire as well. It has always been located between fixed side clamping plate and manifold bolster plate through a wiring grooves to avoid damage.

6.
There are two spacers one titinium and other steel spacer. Manifold height has had its standards according with its runner configurations. During the milling maching operations and grinding operations always there would be a chances to have dimensional discripancy.And also during operation heated manifold will expand by it is own vertically as well. So we have to calculate this expansion according with its operating temp and allow this clearance as a gap between the steel spacer and the clamping plate so that during an operation.Manifold will not leak.

7
.As you can see the water lines passing very close to the insulation pocket area. This will assist initial insulation as well as control gate freezing during each cycle.

Also there are water lines through clamping plate and manifold bolster plate this would reduce the heat transfer as a result of conduction within a hot runner system.

8
.Mastip has different sprue bush lengths to suit diffrent clamping plate thickness.

9
. Air pocket has been always machined around the hot runner manifold in oreder to reduce convective heat flow in the hot runner manifold block to the cavity plates.

Important Note:

One of the common concerns expreseed by molders about hot runner molds is the threat of a leak of molten plastic causing the manifold pocket to fill.

What causes hot runner system leaks?

Most of the hot runner systems don’t leak because of poor design, but they do, if the hot runner manifold is heated beyond its operating processing temperature or not reached its operating temperature. As I said the most common location for leakage is at the flat seal-off between the nozzle and the manifold. We can calculate the thermal expansion and should allow this as a cold clearance during manifold bolster plate pocket machining.
By having this allowance will protect this system from collapsing at the seal off are due to thermal expansion when the system is at operating temperature.

Manifold bolster pocket height= Manifold stack height (Nozzle skirt height +manifold height + total spacer heights + (crush allowance roughly 0.02mm) + expansion at its correct material processing temperature)

Since the correct preload on nozzles and the manifold is so critical it is understandable that the dimensions and tolerances provided by the hot runner supplier must be strictly be look at in order to avoid leakage of the system.

Note:
Mould makers should be carefully inspect all the stack heights and bolster pocket dimensions against the hot runner manufacturer’s manifold drawings.

“What causes my hot runner system leaked during our mould trial?” Some of the most common questions expressed by the toolmakers and injection molders during their trialing period.
It is a strange feeling to see your newly designed plastic mould leaking. Manifold bolster pocket around the new manifold filled with plastic material. It is a kind of threat in the feature to the second trial without knowing the exact problems.
We will see generally, what was caused for this leak.
1. As I mentioned, the most common location for any leakage is at the seal between the nozzle solid skirt top surface and manifold. “Cold clearance”, Mould designers usually forget to apply this clearance. This clearance is the calculated thermal expansion with allowable crush at the systems operating temperature. There is always some variation in the plastic melt temperature coming from the barrel of the injection machine. In exceptional cases up to 40 deg variation has been measured using a high speed thermo-couple.
In these situations, the whole systems would possible be overheated, if the hot runner manifold systems were designed with recommended plastic material melt temperature.
Always refer the supplied manifold drawing and find out the designed operating temperature. This would give you some operating window to do your injection mould trials and eventually can eliminate the permanent damage and expensive replacement with hot runner nozzles and new manifold.

The fact that there is no positive seal in the cold conditions is the main root for the almost every hot runner leakage. In order to maintain this seal to resist the injection forces which would push, the nozzle head and manifold apart from each other at the max injection pressure, Machined bolster pocket dimension should have this cold clearance. Calculation is so easy but when you working by yourself you must check the correct melt temperature and outside ambient temperature
And manifold material coefficient of expansion and exact height of your manifold stack.

For an example I will show you one simple calculation. Standard Mastip manifold thickness = 44mm. Nozzle head = 15mm, Titanium spacer + steel spacer (used to overcome machining tolerances through height adjustment) =11.5mm
Total stack height = 70.5mm

Coefficient of thermal expansion for P20 steel is 0.0000132
Find out the manifold operating temperature say 230 deg and outside ambient temperature say 30 deg.

Thermal expansion= stack height x (230-30) x 0.0000132 = 0.186mm

At hot conditions this stack height will expand by 0.186mm. We must allow this cold clearance to prevent Nozzle, manifold deformation.
Say during the tool trial manifold is heated by mistakenly 330 deg instead of 230 deg.

Thermal expansion= 70.5 x 0.0000132 x (330-30) = 0.279mm.
Components will grow additionally by 0.1 mm. This means that the forces reached roughly almost double, which may well above the yield strength of the nozzle body and manifold steel. Once the overheated systems returns back to 230 deg, System will not develop the necessary sealing pressure.

Externally heated hot runner systems are the majority of the hot runner systems in use. Sometimes inexperienced operators may even forget to turn these heaters on before material injection. Material within the manifold only heated by the help of nozzle coil heaters, sprue bush heater and melt temperature along. This temperature is not sufficient as manifold looses heat as well. Hot runner mould designed with cold clearance that has not reached its expected shut height at the hot conditions, will not have enough surface pressure between the nozzle and the manifold and will eventually leak.

Usually this cold clearance is adjusted in the last mint by the tool makers simply grinding the supplied steel spacers. Once the hot runner systems fully assembled then it is too late.

2. Another silly but the worst scenario would be faulty assembled manifold end plugs; it could be from hot runner manufacturer. But this type of error cannot occur because the entire hot runner manufactures products used to go through their Quality inspection. But still there is a possibility or chance once the end plugs faulty assembled.

Electronic Cigarettes Have The-System-Beat!

Electronic cigarettes have the-system-beat! Cheaper and healtier.

The electronic cigarette is a truly ingenious product that allows the smoker to actually smoke but without inhaling and of the 4000 plus chemicals including some 30+ carcinogens found in regular tobacco cigarettes.

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88-108 MHz PLL FM Synthesizer

This fm synthesizer circuit is played with and optimised design for an 88-108 MHz synthesiser, programmable in 25 kHz steps. It produces about 50 mW output (and thus feeds nicely into the amplifier shown below) with no tuning required other than to set the inputs of the divide-by-N counter to the wanted frequency.

FM modulation is achieved just by injecting audio on the audio input (audio response is pretty flat from 10 Hz to over 200 kHz so can be used for stereo and RDS). This versatile design has also been used for link transmitters at around 48, 52 and 200 MHz with a few changes in the VCO and output filter, and by changing the reference crystal you can alter the channel spacing too. The power output is switched off until the synthesiser achieves lock to prevent transmissions on the wrong frequency (which can be disasterous if you've amplified it to high power and got it connected to a highly resonant antenna).



Source: ZFM

88-108 MHz PLL FM Synthesizer

This fm synthesizer circuit is played with and optimised design for an 88-108 MHz synthesiser, programmable in 25 kHz steps. It produces about 50 mW output (and thus feeds nicely into the amplifier shown below) with no tuning required other than to set the inputs of the divide-by-N counter to the wanted frequency.

FM modulation is achieved just by injecting audio on the audio input (audio response is pretty flat from 10 Hz to over 200 kHz so can be used for stereo and RDS). This versatile design has also been used for link transmitters at around 48, 52 and 200 MHz with a few changes in the VCO and output filter, and by changing the reference crystal you can alter the channel spacing too. The power output is switched off until the synthesiser achieves lock to prevent transmissions on the wrong frequency (which can be disasterous if you've amplified it to high power and got it connected to a highly resonant antenna).



Source: ZFM

88-108 MHz PLL FM Synthesizer

This fm synthesizer circuit is played with and optimised design for an 88-108 MHz synthesiser, programmable in 25 kHz steps. It produces about 50 mW output (and thus feeds nicely into the amplifier shown below) with no tuning required other than to set the inputs of the divide-by-N counter to the wanted frequency.

FM modulation is achieved just by injecting audio on the audio input (audio response is pretty flat from 10 Hz to over 200 kHz so can be used for stereo and RDS). This versatile design has also been used for link transmitters at around 48, 52 and 200 MHz with a few changes in the VCO and output filter, and by changing the reference crystal you can alter the channel spacing too. The power output is switched off until the synthesiser achieves lock to prevent transmissions on the wrong frequency (which can be disasterous if you've amplified it to high power and got it connected to a highly resonant antenna).



Source: ZFM

Paranormal Activity – Scariest Movie 2009

Paranormal Activity – Scariest Movie 2009

Thursday, October 22, 2009

The movie Paranormal Activity was apparently filmed for just 11000 over 7 days and it was bought by DreamWorks – Paramount which originally planned to shelve the lowbudget flick and remake it with bigger stars and a much higher.

paranormal All right folks the official updated list of theaters for Paranormal Activity which managed to land on wide release following the one millionth vote garnered last Saturday night for it has just been released and the. With a razorthin budget a cast of only four people and the events taking place entirely in one locationKatie and Micahs homedirector.



Paranormal Activity surprisingly frightens more with less scares as odd as that may sound. I dont know how to feel about Paranormal Activity. If the person doesnt seem like a real everyday person Paranormal Activity doesnt pull it off. Weve reached a point now where its pretty hard to avoid the buzzing around director Oren Pelis found footage horror – thriller Paranormal Activity especially if any part of your life comes into contact with the Internet.

WATCH “Paranormal Activity” – Official Trailer [HQ HD] 1 min 46 sec www.youtube.com

Did the sleepcam in Paranormal Activity freak you out Then you need to read Ray Vukcevichs short story Whisper published by Small Beer Press in 2001. Featherston does terror very well she isnt too melodramatic or screechy a miscalculation with most femaleinperil characters. Sound on Sight is a site made bymovie buffs for movie buffs. Coming this week to theaters is Where the Wild Things Are Law Abiding Citizen and The Stepfather with surprising hit Paranormal Activity getting a wider release. anyone seen it yet im gonna go friday night.

We cover new movies classic oldies mainstream and independent cinema as well as the latest cinematic events. all my friends say its scary as fuk so im kinda pumped heres a trailer for those who dont know. And this looks like the latter. I love horror films but too many of them rely on either spooky fauxreligious occult crap or arty ie low budget films with a few cheap jump scares. Its not always a good idea to find out what happens while you sleep.

G20 Frequencies

The following frequency list was sent to me by Jeff, N3TAY and have had activity on them today.


170.825 old type of scrambling heard

165.2875 p 25

170.5875 p 25

171.2625 p 25

172.6875 p 25

169.5875 p 25

413.875 heard 3p1294 to control for a radio check. not sure who this is

163.950 encrypted p 25

166.5125 encrypted p25

163.725 p 25

163.110 or maybe 163.1125 hearing aircraft calling for radio checks and various locations for video in p 25

170.815 encrypted p 25

170.880 encrypted p 25

164.400 came up as data and encrypted on my 396xt p25

168.4625 encrypted p25

406.3375 p 25 and some encrypted

407.775 p 25

407.7875 p 25
407.3875 p 25

Some additions to the G20 list

Just received the following frequencies to add to the list. 14:45 Local time.

171.0125 cw id and encrypted p 25

407.1875 p 25

406.975 p 25
167.750 encrypted p25

AMATEUR RADIO

What electronics tutorials on line help is available to become a licensed Amateur Radio Operator?

This site offers some very useful and particularly comprehensive electronics tutorials to help you on your way toward becoming an amateur radio operator. Please feel free to fully explore our site.

Of course many of these electronics tutorials are applicable to experienced constructors as well as advanced electronics students looking for electronics tutorials.

Many other sites also cater for people seeking to become amateur radio operators and conduct electronics tutorials.

Just what is Amateur Radio?

The amateur radio fraternity comprises hundreds of thousands of people world wide who share a very broad common interest. Amateur radio operators come from very diverse backgrounds and age groups. Ranging from adolescents to senior citizens, boys and girls, men and women - amateur radio operators include doctors, bus drivers, vetinary surgeons, painters, engineers, homemakers, university professors, students, politicians, labourers, lawyers and the retired as well as the unemployed, there are no limits to backgrounds.

Somewhere in this wide world there are people with similar interests and backgrounds to yourself who also just happen to be amateur radio operators.

Amateur radio operators are entitled to communicate with one another world wide in accordance with the level of licensing the amateur radio operator has achieved.

What does Amateur Radio Operating entitle me to?

Depending upon your level of licensing for your particular country you might communicate by television, digital communication in conjunction with your computer, by satellite, by traditional high or very high frequency communication using FM, single sideband or more demanding, by morse code. The choice is yours. It depends on your area of interest as an amateur radio operator.

What do I need to do to become a licensed Amateur Radio Operator?

Find out the licensing requirements for amateur radio operators at your location, in particular establish the provisions for sitting for examinations to become an amateur radio operator. Next find out if there are any amateur radio clubs in your locality - the amateur radio operators at these clubs will offer you no end of help provided you approach them in a sensible way. All amateur radio operators remember when they first needed the same help you are now asking for but, remember self help comes first.

Demonstate to your new amateur radio operator friends that you are prepared to put in a bit of work on your own behalf and mainly you need advice, tuition and guidance to pass your exams. Above all else be polite.

Good amateur radio operators are always polite.

Good Luck and please do join us - you will be glad you did - it's real fun.

Ham Radio education

Anyone starting out in ham radio needs a copy of the ham radio bible. It's called "The ARRL Handbook for Radio Amateurs - 2009.

The latest is the 80th edition. It is not called the "electronics bible" for nothing. I have several editions as far back as 1943.

The mammoth 1216 pages translate theory into practice through the large variety of hands-on-projects packed into THE ARRL HANDBOOK. From Antennas to Zener diodes, Transceivers to Switching Power Supplies, HF and VHF Propagation to Power Amplifiers—it’s covered in this edition. Among the newest material is a chapter on digital signal processing, a remote-controlled automatic antenna switch and computer hardware.