With | RADIO CONTROLLED CLOCKS

Spy Cameras With Built In DVR How To Get The Most Out Of Them

Historically, one of the main reasons people have shied away from using hidden cameras or spy cams is because they’ve been so complicated to use. In recent years that has changed. They are easier to use than ever before and we’re to show you how to use them and how to get the most out of them.

First of all they are board cameras hidden inside common everyday objects. Usually that object is a working object to further the deception. Some examples are wall clocks, boomboxes, clock radios, electrical outlets, and many, many more-close to 50 in all.

The purpose of a spy camera is to catch somebody doing something they shouldn’t be doing. So the need for deception is at the very top of the list. That something is usually illegal or immoral or both.

There is a new line of covert cameras with a DVR built right in. Here is how to get the most out of it and how to use it.

1. Once you get your camera make sure all the parts are included.

2. Read all the directions.

3. Aim the camera in the general direction you want to record.

4. Put the SD card into the provided slot.

5. Plug the power cord into a wall outlet. The power cord runs the device, the camera and the DVR. No other wires are needed.

6. The DVR runs a test on its own.

7. Then the unit will show live video and it’s ready to record.

8. Press the record button on the included remote control.

9. To play back what you recorded remove the SD card and insert it into your SD card reader on your computer.

You need some kind of media player software. If you don’t have one you can download the free VLC media player from the Internet.

Download VLC Player to compare and see all its features and the media playable.

Those are the steps to use the new hidden cameras with DVR. Easy? You bet. When are you getting one?

Incoming search terms for the article:

Dealing with Time across the Globe

No matter where we are in the world we all need to know the time at some point in the day but while each day lasts for the same amount of time no matter where you are on Earth the same timescale is not used globally.

The impracticality of Australians having to wake up at 17.00 or those in the US having to start work at 14.00 would rule out suing a single timescale, although the idea was discussed when the Greenwich was named the official prime meridian (where the dateline officially is) for the world some 125 years ago.

While the idea of a global timescale was rejected for the above reasons, it was later decided that 24 longitudinal lines would split the world up into different timezones. These would emanate from GMT around with those on the opposite side of the planet being +12 hours.

However, by the 1970’s a growth in global communications meant that a universal timescale was finally adopted and is still in much use today despite many people having never heard of it.

UTC, Coordinated Universal Time, is based on GMT (Greenwich Meantime) but is kept by a constellation of Atomic Clocks. It also accounts for variations in earth’s rotation with additional seconds known as ‘leap seconds‘ added once of twice a year to counteract the slowing of the Earth’s spin caused by gravitational and tidal forces.

While most people have never heard of UTC or use it directly its influence on our lives in undeniable with computer networks all synchronised to UTC via NTP time servers (Network Time Protocol).

Without this synchronisation to a single timescale many of the technologies and applications we take for granted today would be impossible. Everything from global trading on stocks and shares to internet shopping, email and social networking are only made possible thanks to UTC and the NTP time server.

Richard N Williams is a technical author and specialist in Atomic Clocks, telecommunications, NTP and network time synchronisation helping to develop dedicated NTP clocks. Please visit us for more information about an NTP server or other NTP time server solutions.

Problems With Clock Radios

Sometimes alarm clock radios break down. However, we can take the time to repair them ourselves. The following is what to do to repair them.

1. Check the power at the outlet, and make sure the power is on.

2. Check the pointer. Some household radios use a station frequency pointer mounted on a dial cord that is moved by a small wheel on the side of the clock radio. Other household radios use a digital frequency readout that cannot be adjusted.

3. If the sound is fuzzy, disassemble the unit and locate the volume control. Spray electrical contact cleaner into the control and rotate or slide the control several times to lubricate the mechanism.

4. Replace a damaged or broken antenna.

Most modern clock radios are built on printed circuit boards that can only be repaired by trained technicians. Some of the tools you may need are screwdrivers, wrenches, electronic control cleaner, denatural alcohol, soldering iron and solder.

Reset Dial Pointer

1. Turn on radio. Find a strong radio signal, listen to the frequency.

2. Use a piece of tape or grease pencil to mark the dial where the pointer should be for that frequency.

3. Unplug the receiver and open the housing. There are usually two to four screws in the underside of the radio.

4. Inspect the pointer mechanism for problems, such as a cord that came off at the end rollers, or a break in the cord. Replace the broken cord or repair it.

5. Loosen the spring clips Move the pointer along the dial cord until the station being received lines up with the tape or mark on the dial.

6.Tighten the clips on the cord. Make sure you do not move the pointer.

7. Plug the radio in and verify that the dial pointer reads correctly.

Replacing External Antenna

1. Loosen the antenna screw.

2. If there is no exterior screw, open the radio and access the antenna base.

Replacing an Internal Antenna

1. Unplug the receiver and open the housing.

2. Find and remove the internal antenna, of the internal base of the external antenna.

3. Inspect the wires wound around the antenna for serious damage. Make sure the antenna is firmly plugged into the main circuit board. If the antenna is damaged, replace it or attempt to repair the antenna, or replace the radio as a unit.

Clean Electronic Components

1. Unplug the receiver and open the housing.

2. Use canned air to blow dust from components, including any power cords and speaker jacks.

3. Use electrical contact cleaner, or a cotton swab dipped in dentured alcohol to clean electronic components.

4. If you find broken components on a circuit board, replace the circuit board. Before purchasing a circuit board, you can use a soldering iron and electronic solder to attempt a repair.

Now you have repaired the clock radio yourself.

Sometimes alarm clock radios break down. However, we can take the time to repair them ourselves. The following is what to do to repair them.

1. Check the power at the outlet, and make sure the power is on.

4. Replace a damaged or broken antenna.

Reset Dial Pointer

1. Turn on radio. Find a strong radio signal, listen to the frequency.

2. Use a piece of tape or grease pencil to mark the dial where the pointer should be for that frequency.

3. Unplug the receiver and open the housing. There are usually two to four screws in the underside of the radio.

4. Inspect the pointer mechanism for problems, such as a cord that came off at the end rollers, or a break in the cord. Replace the broken cord or repair it.

5. Loosen the spring clips Move the pointer along the dial cord until the station being received lines up with the tape or mark on the dial.

6.Tighten the clips on the cord. Make sure you do not move the pointer.

7. Plug the radio in and verify that the dial pointer reads correctly.

Replacing External Antenna

1. Loosen the antenna screw.

2. If there is no exterior screw, open the radio and access the antenna base.

Replacing an Internal Antenna

1. Unplug the receiver and open the housing.

2. Find and remove the internal antenna, of the internal base of the external antenna.

Clean Electronic Components

1. Unplug the receiver and open the housing.

2. Use canned air to blow dust from components, including any power cords and speaker jacks.

3. Use electrical contact cleaner, or a cotton swab dipped in dentured alcohol to clean electronic components.

4. If you find broken components on a circuit board, replace the circuit board. Before purchasing a circuit board, you can use a soldering iron and electronic solder to attempt a repair.

Now you have repaired the clock radio yourself.

Sometimes alarm clock radios break down. However, we can take the time to repair them ourselves. The following is what to do to repair them.

1. Check the power at the outlet, and make sure the power is on.

4. Replace a damaged or broken antenna.

Reset Dial Pointer

1. Turn on radio. Find a strong radio signal, listen to the frequency.

2. Use a piece of tape or grease pencil to mark the dial where the pointer should be for that frequency.

3. Unplug the receiver and open the housing. There are usually two to four screws in the underside of the radio.

4. Inspect the pointer mechanism for problems, such as a cord that came off at the end rollers, or a break in the cord. Replace the broken cord or repair it.

5. Loosen the spring clips Move the pointer along the dial cord until the station being received lines up with the tape or mark on the dial.

6.Tighten the clips on the cord. Make sure you do not move the pointer.

7. Plug the radio in and verify that the dial pointer reads correctly.

Replacing External Antenna

1. Loosen the antenna screw.

2. If there is no exterior screw, open the radio and access the antenna base.

Replacing an Internal Antenna

1. Unplug the receiver and open the housing.

2. Find and remove the internal antenna, of the internal base of the external antenna.

Clean Electronic Components

1. Unplug the receiver and open the housing.

2. Use canned air to blow dust from components, including any power cords and speaker jacks.

3. Use electrical contact cleaner, or a cotton swab dipped in dentured alcohol to clean electronic components.

4. If you find broken components on a circuit board, replace the circuit board. Before purchasing a circuit board, you can use a soldering iron and electronic solder to attempt a repair.

Now you have repaired the clock radio yourself.

TheWatchTheClock.Com

The author is retired. She keeps herself busy by doing things she likes to do. Here are some of her hobbies: gardening, reading, cooking, baking,hiking, and occasionally dabbles into writing. She also enjoys traveling.

Sharpening Time Management Skills With Wireless Clocks

Schools and universities are the venues for the youth of our future to learn the basics of life. Everything from the sciences to the arts is taught here. Some lessons are learned there which do not need the four corners of the classroom to be taught. Among these valuable lessons is time management. Many do not realize that proper management of time is the key to doing what needs to be done everyday. Here are a couple of tips for students to sharpen their time management skills with wireless clocks:

When they are inside the campus, them actually have a lot of resources to help them tell time. For instance, their wristwatch, the wall clock, and the internal clock of their mobile phones are just some of the devices which keep time for student. Rarely will all of these tell the same exact time leading them to get confused of which time to follow.This dilemma is now eradicated with the help of these wireless clock systems. What benefits do these types of wireless clocks hold for the school and for the students as well?

For starters, when all of the clocks are synchronized within the school, all classes and other activities will start and end at the correct time. Students can now say goodbye to lengthy overtime discussions of teachers who get too carried away with the topic. The school can also help track students who like to come in late or dismiss themselves earlier than the allotted time for their classes.

Making a schedule and following it the best that one can is one way to teach proper time management skills to students. A schedule is only as good as the time that it follows, and this is only possible if time told within the campus is the same for all locations which of course is easily achieved with these synchronized clocks.

Another advantage that this system has is that it helps the school save on the expenses and costs. Unlike the conventional wired clocks which costs more and are relatively hard to program. Even with low priced battery powered versions, they may be the cheapest choice but the reliability of the time told is drastically reduced, and the cost of having to change batteries is immense, considering how many clocks are required in a school setting.

Wireless clocks are indeed the best investment for schools and universities to help make the environment more conducive to learning. Not only will they be teaching the formal education, but the more important life lessons such as using time wisely.

To know more information about Wireless Clocks and Radio Controlled Clock visit ATSClock.com

Programmable Crystal Oscillators with Subps Jitter and Multiple Frequency Capability

With a market size for quartz crystal devices estimated at more than $2 billionand more than

four billion crystals supplied annually, Professor Holton’s prognostication has been overwhelmingly fulfilled.Crystals have become not only the heart of telecommunications equipment, but also the electronic pulse in computers, printers, cameras, engine controls, cellular phones and a host of other applications.

In 1939, the U.S. Army embarked on a path to adopt crystal control for radio communications. By providing robust radio communication at precise frequencies, quartz crystals transformed the LC-tuned radios of the day into vital communication tools. With the war effort underway, the frequency control industry was experiencing astounding growth. Indeed, the crystal industry lived hand-to-mouth due to material shortages of quartz. Long manufacturing processes mandated excessive and often unpredictable lead times. Worse yet, reports of high failure rates began to come back from the field. Late in 1943, the following telegram was received by the U.S. Army’s Office of the Chief Signal Officer:

COMMUNICATIONS EIGHTH AIR FORCE BASED IN BRITAIN

BROKEN DOWN LACK OF CRYSTALS FIND CAUSE CURE SAME

Naturally, this generated a large failure analysis effort by the Army, with the result being diagnosis of an aging problem caused by contamination on the quartz surface. It was determined that reliable operation of quartz crystals is only possible when they are sealed in clean, dry, hermetic packages.

Oscillator packages today are smaller; stabilities are tighter, and frequencies are higher. Yet, quartz crystals are still fabricated in much the same way that they were in 1943. Each new frequency requires a new crystal to be cut, x-rayed, lapped, mounted and sealed into the final package. Additionally, the aging and reliability problems experienced by the 8th Air Force in 1943 have been exacerbated by new techniques to achieve higher frequencies by chemically thinning the quartz into inverted mesa shapes.

While programmable oscillators introduced in the 90s offered the promise of reinvigorating the manufacturing process, the phase-locked loop (PLL) synthesis techniques employed generated so much jitter that they were only useful in low-performance applications.

And so, the quartz industry has remained largely strapped to the same manufacturing methods of the 1940s for producing quartz crystal oscillators. Each new frequency requires a new ‘rock.’

Implication of Circuit Architecture on Hybrid Crystal Oscillator Manufacturing

As shown in Figure 1, the basic architecture of a crystal oscillator is quite simple. Gain block A represents the oscillator sustaining-amplifier, and block B is the feedback network containing the crystal resonator.

Barkhausen’s well-known criteria for oscillation states that if a frequency exists where the phase around the loop is zero, and the gain of A exceeds the loss of B, then the circuit will oscillate at that frequency. The obvious implication with a narrowband resonator, such as a quartz crystal, is that each new frequency requires a new crystal with the manufacturing consequences being quite profound.

Thousands of distinct crystal frequencies are required to support the wide variety of electronic systems in production today. The required temperature ranges and frequency stabilities are also variable; so, the quartz bar cutting angles must also vary. Not only must the quartz crystal thickness be unique for each different frequency, but the angle of cut from the quartz bar is also varied for different order.

begin with quartz blank fabrication. If blank design changes are required due to difficulties encountered in the testing phase, the process must restart at cutting.

One only needs to tour a typical crystal oscillator factory to see the staggering array of crystals in production at any given point in time. In addition to requiring long and often unpredictable lead times, this build-to-order process complicates implementation of modern manufacturing systems such as statistical quality control or continuous improvement. High-frequency fundamental (HFF) crystals required for low-jitter clocks undergo additional chemical milling of the blank to achieve quartz thicknesses of tens of microns, further exacerbating processing issues.

The situation is no less complicated for SAW-based oscillators where each new frequency requires a new wafer mask to be developed. This requires CAD layout, mask fabrication and wafer processing to be performed for each frequency.

It is quite an achievement that the quartz industry has been able to develop production methods compatible with this tremendous product mix and associated complex quartz processing.

A Frequency-Programmable Architecture For Low Jitter Clock Generation

Over the past few years, advances in fine line CMOS process technology have enabled IC designers to develop high-frequency PLL technology for use as frequency agile clock multipliers and jitter attenuators in multi-giga bit per second optical networking applications. By using this technology to create a new class of hybrid oscillator, many of the manufacturing complexities and performance issues traditionally associated with high-frequency resonators can be eliminated.

This new class of oscillator combines a fixed low-frequency crystal resonator with a new DSP-based PLL architecture known as DSPLL® as shown in Figure 3. The DSPLL is programmed with a multiplication value to translate the fixed low-frequency crystal frequency to the desired output frequency. Using this architecture, high-frequency clocks operating at over 1 GHz are possible with jitter performance that is comparable to traditional high-performance voltage-controlled crystal oscillators (VCXOs) and voltage-controlled SAW oscillators (VCSOs).

The DSPLL engine was designed with 1 ppb resolution over a tuning range that spans 10 to 945 MHz. Above 945 MHz, oscillator operation is limited to select bands to 1.4 GHz. All frequencies are synthesized from a fixed external crystal using a basic feedback oscillator topology. The crystal resonator need not be of high accuracy and does not need to be pullable as all fine frequency tuning is performed digitally via the DSPLL clock synthesis IC. Non-volatile memory (NVM) is provided on-chip to maintain frequency synthesis settings when supply voltage is cycled.

A key advantage of this architecture is that a wide range of low-jitter, high-frequency clock signals can be generated from a conventional fixed frequency overtone quartz crystal. This eliminates the need to fabricate unique HFF crystals or SAW resonators for each frequency. Besides the obvious manufacturing issues associated with maintaining a wide range of different resonator frequencies to support a diverse set of customer requirements, HFF crystals and SAW resonators both have reliability and performance issues that can be significantly improved upon through the new oscillator architecture.

Hybrid Clock Module With Fixed Frequency Crystal

The DSPLL clock synthesis IC was designed to be packaged together with a quartz crystal into a hermetic ceramic package to support both crystal oscillator (Si530 XO) and voltage-controlled crystal oscillator (Si550 VCXO) applications. Figure 4 shows a functional block diagram of the Si550 hybrid VCXO incorporating the DSPLL technology. A provision to enable or disable the output signal is available through the OE pad. A fixed frequency crystal, such as 120 MHz third overtone, is used inside of the ceramic, hermetically-sealed, hybrid module.

As in conventional hybrid XOs and VCXOs, high-temperature, co-fired ceramic (HTCC) is used for the package, and the lid is welded using seam-sealing techniques. Package hermeticity is better than 5×10-8 ATM-cc/sec, as verified by helium fine leak testing. Industry-standard 7 x 5 mm package dimensions and pad layouts are used for backward compatibility with existing oscillator products.

Revolutionized Manufacturing Flow

A manufacturing flow that is tailored for short lead times and process optimization as shown in Figure 6 is made possible by hybrid oscillators incorporating the DSPLL clock synthesis IC. In this flow, an inventory of ‘raw’ unprogrammed oscillators is produced by hermetically sealing the DSPLL IC together with the low-frequency crystal blank. While the hybrid assembly of the crystal blank and IC share some similarities to the flow, there are two major simplifications. First, only one frequency of crystal blank is required; and second, the fine frequency-tuning step is eliminated. This allows for continuous improvement of the blank and hybrid assembly process while eliminating an entire processing step.

In response to customer orders, ‘raw’ devices are pulled from inventory, programmed to satisfy customer frequency specifications and shipped. Thus, the order fulfillment flow changes from a complex build-to-order process with eight-week lead times to a simple program-to-order process with one-week lead times. In addition to offering much shorter lead times, this method also facilitates modern techniques, such as lean manufacturing and continuous improvement.

Improved Initial Frequency Accuracy

Oscillator designs using the DSPLL clock IC for high-resolution frequency synthesis eliminate one of the largest variables that determines the initial accuracy of XOs. Both traditional crystals and hybrid XOs experience a two-step frequency adjustment process. The first step, termed base plating, is performed in a batch mode using thin-film deposition techniques, such as sputtering. A monitor crystal is co-located with devices to be plated, and the frequency is monitored as a measure of film thickness. Since varying the film thickness slightly alters the vibrating mass, the frequency can be slightly adjusted by trimming the film thickness. This technique is limited to an accuracy of a few hundred ppm; so, a second fine-tuning process is required. Fine-tuning involves selectively adding or removing metal from the surface of the quartz and again modifying the vibrating mass. Frequency is continuously monitored, and the process is stopped when the target frequency is achieved. The process sensitivity is quite severe for HFF crystal oscillators. Since a single atomic layer of metal may cause the frequency to change by many tens of ppm, achieving an initial tolerance of 10 ppm requires depositing less than one atomic monolayer. Unfortunately, the oscillator must then be sealed, and the resulting change in parasitic capacitance causes additional changes in frequency. Residual mechanical stresses in the package also cause frequency shifts. For HFF VCXOs, initial accuracy may be in the several tens of ppm. SAW oscillators are similarly affected by the ability to control ultra-thin film deposition and residual package stresses.

By incorporating high-resolution frequency synthesis into the DSPLL clock IC, the oscillator frequency is set through a simple programming step rather than the traditional two-step tuning process. In contrast, the specifications for the crystal resonator in DSPLL-based hybrid oscillators can be relaxed to an initial accuracy of ±10,000. As a result, only the initial baseplating of the crystal is necessary, and the fine-tuning step can be eliminated. Additionally, the frequency shifts due to both parasitic capacitance change and residual package stress can be compensated for since the oscillator is programmed to the final frequency after sealing. Finally, because the DSPLL clock IC offers programming resolution of less than one ppb, it would be expected that initial frequency accuracies of one ppm are possible for high frequency XO and VCXO devices. This is roughly an order of magnitude better than traditional high frequency oscillators.

Improved Aging Performance

Operation on an overtone reduces the resonator C1 by the reciprocal of the overtone, squared. This means that a third overtone crystal will have approximately one-ninth the pull range of a fundamental, and a fifth overtone will have only one-twenty-fifth the pull range. While this is beneficial for high-stability OCXOs, this is undesirable for wide-pull VCXO operation and essentially mandates the use of fundamental mode crystals. Achieving adequate pull range is the underlying reason behind the use of HFF crystals for VHF-band VCXOs, such as 155 MHz. It is well known that aging performance is related to the inverse of quartz blank thickness (i.e. a thick quartz blank can have superior aging). For example, a 38.8 MHz fundamental-mode resonator will have aging stability superior to that of a 155 MHz resonator. The 38.8 MHz fundamental will also have a third overtone resonance at 116.4 MHz. Since the oscillator is not directly pulled with the DSPLL architecture, this resonator can readily be used in a VCXO using the Si5301 IC. Since the resonator thickness of a 116.4 MHz third overtone will be four times the thickness of a 155 MHz fundamental, aging performance will be similarly improved. Aging for the module is specified at ± 10 ppm over a typical 15-year life. This contrasts with typical SAW or HFF aging of several ppm/year.

Low Jitter Clock Signals

Jitter is a critical clock signal parameter for many applications and is a major factor in determining key system attributes, such as bit-error-rate (BER). Jitter is derived from an integration of phase noise over a specified bandwidth.

Phase noise performance at offsets lower than 10 kHz is determined primarily by the on-chip crystal oscillator, while the output LVPECL signal levels largely set the noise floor for offset frequencies greater than 10 MHz. Intermediate frequency phase noise performance is determined by the on-chip VCO and associated PLL components. Jitter derived from integration of phase noise is 0.332 ps over the bandwidth of 12 kHz to 20 MHz and 0.319 ps over the bandwidth of 50 kHz to 80 MHz. This performance essentially matches performance results typically obtained when using high-performance

SAW or HFF resonators in the conventional feedback oscillator topology of Figure 1. Depending on the ratio of output frequencies to crystal resonator frequency, some spurious signal content may be generated. At a specified value of -80 dBc, spurious content is substantially lower than previously available in programmable clocks.

Programmable Tuning Slope

Traditional VCXOs utilize a varactor diode to modify the resonant frequency of the oscillation loop. Since the loop-resonant frequency is modified by the well-known C1/2(C0+CL), where C1 and C0 are crystal equivalent circuit values and CL is the load capacitance, changes to CL affect the output frequency. Non-linear behavior in the oscillation loop determines the overall tuning slope linearity. The tuning slope, Kv, is measured in ppm/V and is directly proportional to the crystal motional capacitance C1.

In contrast, the tuning voltage, Vc, is digitized on the DSPLL IC through a high-resolution ADC. The resulting digital number is used to slightly modify the frequency synthesis engine and hence the output frequency. Since Kv is simply a numerical multiplication factor, differing values of Vc can be programmed after the oscillator is assembled.

These results were obtained from a single hybrid oscillator by simply reprogramming the value of Kv. With a programmable gain ranging from 15 to 270 ppm/V, Kv effectively emulates typical characteristics of most SAW and crystal VCXOs. The small roll-off at voltages above 3 V is due to slight drooping of the reference voltage for the ADC converter as Vc approaches VDD. Linearity, particularly for the most useful range below 3V, is dramatically improved compared to conventional varactor-based VCXOs.

Multiple Frequency Operation From One Crystal Resonator

Applications are emerging that require multiple clock frequencies slightly offset from each other. For example, 622.08 MHz is a widely-used SONET transport frequency. Forward error correction (FEC) is used to improve bit error rate performance; so, additional bits must be interleaved within the SONET payload. This increases the clock frequency to a slightly higher frequency, such as 666.5143 MHz. Conventional technology VCXOs must use distinct crystals or SAW resonators for each unique frequency. This approach becomes increasingly untenable as the number of required frequencies increases beyond two. Using DSPLL clock synthesis, multiple output frequencies can readily be generated from a single resonator. Using packaging similar to Figure 5, dual frequency XO (Si532) and VCXO (Si552) oscillator modules have been developed that provide two selectable output frequencies from a single quartz crystal. In the quad XO (Si534) and VCXO (Si554) series, additional pads are provided on the ceramic package for binary selection of four individual output frequencies. Similar to the dual frequency parts, only one quartz crystal is required, and the choice of output frequencies is arbitrary within the operating bandwidth of the DSPLL IC.

Summary

A new class of crystal oscillators has been developed which offers high-resolution, programmable frequency and high performance. These oscillators dramatically simplify the manufacturing process and thereby shorten product lead times. Additional performance advantages include better initial frequency accuracy, long-term aging and voltage control linearity.

Silicon Labs – Clock Jitter, 8051 Microcontroller and Crystal Oscillator