USB Standby Killer Circuits Diagram

When turning a computer on and off, various peripherals (such as printers, screen, scanner, etc.) often have to be turned on and off as well. By using the 5-V supply voltage from the USB interface on the PC, all these peripherals can easily be switched on and off at the same time as the PC. This principle can also be used with other appliances that have a USB interface (such as modern TVs and radios). 

USB Standby Killer Circuit Diagram :

This so-called ‘USB-standby-killer’ can be realised with just 5 components.

The USB output voltage provides for the activation of the triac-opto driver (MOC3043) which has zero-crossing detection. This, in turn, drives the TRIAC, type BT126. 

The circuit shown is used by the author for switching loads with a total power of about 150 W and is protected with a 1-A fuse. The circuit can easily handle much larger loads however. In that case and/or when using a very inductive load a so-called snub-ber network is required across the triac. The value of the fuse will also need to be changed as appropriate. 

The circuit can easily be built into a mains multi-way power board. Make sure you have good isolation between the USB and mains sections (refer to the Electrical Safety page published regularly in this magazine). 

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PC Power Box with E-fuse Circuit Diagram

This little circuit can assist you to get rid of all surplus tiny ac mains adaptors from your desktop. The circuit is nothing, however a sensible dc power box directly powered by the smps of your desktop pc. Regulated, clean and guarded +12VDC is offered at the output of this unit. additionally, a USB power port is provided to re-charge transportable devices as well as cellphones and music players, etc.

How will the computer power box works

All you would like is to open your system box and connect an unused 4-pin drive power connector from the system smps to the current circuit. +12V (Yellow wire) from the smps is processed by a resettable electronic fuse designed around elements T1, T2 and T3 and feed to the output terminal. equally the +12V is down converted to stable +5V by fastened three pin regulator IC1.

PC Power Box with E-fuse Circuit Diagram

Smart dc power box circuit schematic

As a result, +12V (500 -750mA max, based mostly on the electrical characteristics of T2 used) and +5V (1A max) DC provides are obtainable for external use, while not affecting the traditional computer functions. Switch S1 is that the power on/off cum reset switch. Resistor R3 sets the utmost allowable output current rate and T1 disables the output power switch T3, when output load current exceeds the set price.

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PC Heat Monitor Circuit Diagram

The PC processor generates very high temperature during its operation which is dissipated by the large heat sink placed above the processor. If the heat sink assembly is not tight with the processor or the cooling fan is not working, PC enters into the Thermal shutdown mode and will not boot up. If the PC is not entering into thermal shutdown, the high temperature can destroy the processor. This simple circuit can be placed inside the PC to monitor the temperature near the processor. It gives warning beeps when the temperature near the heat sink increases abnormally. This helps to shutdown the PC immediately before it enters into Thermal shutdown.

The circuit uses a Piezo element (one used in Buzzer) as the heat sensor. The piezo crystals reorient when subjected to heat or mechanical stress and generates about one volt through the Direct piezoelectric property. IC1 is designed as a voltage sensor with both the inputs tied through the capacitor C1.The non inverting input is connected to the ground through R1 to keep the output low in the standby state. The inputs of IC1 are very sensitive and even a minute change in voltage level will change the output state.

 

In the standby mode, both the inputs of IC1 are balanced so that output remains low. When the Piezo element accepts heat, it generates a minute voltage which will upset the input balance and output swings high. This triggers LED and Buzzer. Capacitor C2 gives a short lag before the buzzer beeps to avoid false triggering. Warning beep continues till the piezo element cools.

Note: Enclose the circuit inside the PC with the piezo element close to the heat sink of the processor. Adjust the distance between the piezo element and heat sink so as to keep the circuit standby in the normal condition. The piezo element can sense a 10 degree rise in temperature from a distance of 5 cms. Power to the circuit can be tapped from the 12 volt line of SMPS.

Sourced by Dr. Mohn kumar

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USB Keyboard Made from Old Typewriter

Looking for a unique gift? Here’s an antique typewriter which has been modified to function as a USB Keyboard for PC, Mac, or even iPad. That’s very cool, isn’t it?

In the world of obsolescence, this USB typewriter is a groundbreaking innovation. It does not change the outward appearance of the typewriter and is easy to install since there is no messy wiring. The 3 components of the USB typewriter are the Sensor board, the USB switches, and the Reed Switches.

It works like a regular typewriter with all letters, numerals, and punctuation marks as well as shift, space, and return carriage. It’s a better addition to your home office.

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Bluetooth Keyboard Controls Dancing Hexapod

Presently, production of robots of different types and functions are rapidly created to help people make their life easier. We can even imagine how the world would look like on the next decade to come. That is – robots do most of the work that people used to do.

Most of the bots in the market are not controlled by Bluetooth except this bot. It’s amazing how this bot dances while controlling the Bluetooth keyboard and a lot of fun to watch for robot fanatics.

In spite the advantages of bots, it can shut down if operation failed therefore failure on its task. Then back to basics must always be a backup.

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Your PC Needs Some Illumination

Try to lighten up you PC by using LED flex lights to surround the casing. The result will be much appreciated when the room is dark. The chain is housed in rubber plastic which makes more light to be projected out right angles as if some miracle is happening inside the PC.

You can choose which color to use or what you wish to blend with the design of your room. The LED strips are very flexible and customizable which makes them popular. It is very easy to install these strips by using Velcro strips of adhesive backing. You may also use the LED strips in any part of your room like the hairdresser mirror. Click here to visit the project page.

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Laptops Cord Stays off Your Lap with this Clip

Someone just got this trick works on all the uni body Mac Books and helps keep your wires and cord under control.



This clip is especially bendy if you are lounging on the sofa with the power-cord-side in towards the cushions. It keeps your MacBooks power cord under control with this trick and to stop it from tugging in you. Its built-in cable clip the one that keeps your cord wrapped around the power brick and clip it to the side of your laptops screen.

The cable pulls it up off your lap and keeps it neat and tidy not to mention free of crazy fall across the keyboard loops.

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Apple II computer fit on your wrist (streampowers)

Disclaimer: streamPowers.blogspot.com is not responsible for any damage caused to your devices due to any information found on this site.  Please use this knowledge at your own risk.

About a year ago I came across an interesting article in Make Magazine about a guy who took his Fossil Wrist PDA and installed an Apple II emulator on it.  He was able to load many of the Apple II software titles and run them at regular speed.  The thought of having a fully functioning Apple computer on my wrist excited me enough to give it a try.   

People that are attempting to do this should be familiar with the Palm OS as well as using jot or Graffiti 2 as an input method.  The Fossil Wrist PDA (now discontinued) features a tiny gray 160×160 pixel screen, the same number of pixels as most palm devices up to Palm III, with 16 shades of gray. The watch runs Palm OS 4.1 with its 66MHz processor and has a tiny stylus hidden in the watch clasp. It is able to carry out most PDA functions, and run any normal Palm OS-compatible application (up to 4.1). It features 8 Mb of RAM (about 7.7 Mb available to user) and 4 Mb of flash memory. Like other Palm OS devices, it can synchronize or exchange information with PC or Mac, has, a virtual keyboard, and a touch screen with indiglo. The device also has a watch mode, with several “watch faces” to display the time.  These things were only out for a couple of years and were available in 2 different models.  You can usually find the first model on ebay going for about 50 bucks.  I was able to find a second gen one (FX2008) which is much more eye appealing for about $80 dollars brand new.  This isn’t a bad price considering they were $199 when they were first released. 

The first thing you will need to make this work (besides the watch) is an Apple II emulator called Appalm, which can be downloaded here.  Next you will need some Apple software disk images.  You can do a web search for “apple II roms” and should come across some sites which have software already in the *.dsk format.  Of course it is only legal to use these images if you own the original software disks.  The emulator requires you to convert the dsk files in to a file that the watch can actually read called pdb files.  The emulator’s zip file comes with an MS DOS executable to do this for you.  The emulator comes with easy to understand readme file, that will tell you how to set everything up.  One note before choosing which software to run, the watch display is incredibly small and sometimes text can be unreadable, unless you’re using a microscope.  Also the game controls are not optimal.  The emulator has a button mapping feature, but there are only 3 buttons and an up and down rocker switch that can be assigned a function.  If you want to load some games I recommend playing text based games like Zork or games that only require an up and down or a left and right movement like Galaxian or Zaxxon.  The watch lets you enter text by drawing in either jot or graffiti right on the screen and responds pretty well.  Installation of the emulator is pretty easy.  Just sync all the included palm files as well as some software on to the watch, and after the unit resets you should see the emulator icon.   

After the program boots you should see the Apple IIe boot screen.  Tap the tab at the top and select load disk image 1.   

 

Then choose the disk image you want to load, and check the box reset after load.  After 7 seconds or so your original apple program should now load, tap the tab at the top again to customize your other options, like input and emulation output (which I like to speed up).  I reassigned the right top and bottom buttons to be used as joystick one and two buttons (this is good for a game like Karateka).

 

  

 

 

 

So there you have it an Apple II wrist watch, definitely cooler then that old Casio calculator watch you use to sport.  You probably won’t want to play around for too long though, being your controls are really limited and you can get a headache from squinting at the screen for too long.  Battery life is also an issue but it is good for bringing back those old nostalgic memories of playing on an Apple II.  One side note, I also found a commodore 64 emulator that should work as well, just something else for you to try after your Apple project. [link]

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How to Upgrade Your USB Hub

Problems can arise with USB hubs that are powered from a PC when gadgets plugged into them draw too much current. This is often the case with devices fitted with USB cables that are too long or too thin, causing voltage drop. There’s no need to scrap your old USB hub, however, if you upgrade it using this little circuit and an external power supply. Just cut the 5-V power wire of the USB cable inside the hub and solder a diode (D1) in the pass-through direction. Now connect the 5 V wire from the external power supply to the cathode of this diode. D1 prevents any current from the power supply from flowing back into the PC.

 USB Hub Circuit Diagram

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Cross-Linking With Two Patch Cables

In networks, the supremacy of coax cable is a thing of the past. Nowadays, Ethernet connections are made using UTP cables. The BNC plug has yielded to the 8-way RJ45 plug. Previously, coax cables were daisy-chained from computer to computer and terminated at the two ends using 50-_ resistors, but modern networks use central ‘socket boxes’ (switches and/or hubs) to interconnect everything. The connections between the hubs and the computers are made using patch cables having the same sequence of leads in the RJ45 connectors at each end. For making a direct connection between two computers without using a hub or switch, a ‘crossover cable’ is used.






Such a cable has the leads cross-linked in order to allow the two computers to directly communicate with each other. If there are problems with the network, it can be handy to be able to directly interconnect twocomputers, or directly connect a computer to a cable or ADSL modem without using a hub or switch. A long crossover cable is not always available, and shoving around computers is not an attractive alternative. Consequently, we can use a dual RJ45 wall outlet box to construct an adapter, which can be used to interconnect the two patch cables coming from the equipment in question. This outlet box must be wired to create a cross-linked connection. This is done by making the following internal connections:

• 1 → 3
• 2 → 6
• 3 → 1
• 4 → 4
• 5 → 5
• 6 → 2
• 7 → 7
• 8 → 8

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USB Enabled Remote Control

The objective of a remote control is to have the ability to operate a device from a certain distance. Nevertheless, remote controls usually are in places where we need to move around to find. This makes the remote totally useless as you may have used that time and energy to operate the device personally. If we take into account the limited reach that remote have, along with the fact that they are battery operated, we have an obsolete technology. All this can be fixed by developing a new remote control system.

A lot of designs have been completed on systems that operate by clapping. But they have some disadvantages. Such as the fact that they work over only one sound or command. Another fact is that daily activities must be interrupted to give a command.

A whistling command system has been developed to control domestic devices. It works by detecting the sound peaks that are uniquely produced by whistles. Sound from each whistle is processed to give the order to the device.

The sound is received by a mic placed in the room. The microphone is connected to a USB device that transfers the information to a Linux operated computer. Once the command is recognized, the computer sends it to the device.

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Computer Case Mods Warhammer 40K

This modder has constructed this detailed case with props and metallic textures to build this impressive masterpiece. It has moving parts such as a spinning turret and weaponry and to think this is just a PC case is extraordinary.

It is a huge case mod made of wood, metal and acrylic, this new creation has made people feel like seeing it this time with a real-looking thrilled addition.

The minigun on the hands of the dreadnought along with its rotating feature shows an awesome look. It is enhanced with computerized features, hardware and accessories. Everything used for adding a bit of detail to this dreadnought is perfect and in the right proportion.

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Modded PC Inspired With Frank Lloyd Wright

You think you already see all the possible case mods? This mod was inspired by the work of the famous Fallingwater architect Frank Lloyd Wright.

The inspired drink bar cantilevered roofs from teak, mahogany highlights, the Cherokee red and covered wagon code colors it is enough to architecture nerd powerlessness. Its fine styling sports has an Intel Core i7-875 GB on Mini-ITX motherboard, with 8 GB of system memory. It has a 256 GB SSD with a 2 TB hard drive.

This desktop cases don’t really tend to get hot, just the components and definitely wouldnt be worried about a fire-hazard. The top looks like it has pretty good airflow too.

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Simple LCD Module in 4-bit Mode

In many projects use is made of alphanumeric LCDs that are driven internally by Hitachi’s industry-standard HD44780 controller. These displays can be driven either in 4-bit or 8-bit mode. In the first case only the high nibble (D4 to D7) of the display’s data bus is used. The four unused connections still deserve some closer attention. The data lines can be used as either inputs or outputs for the display. It is well known that an unloaded output is fine, but that a floating high-impedance input can cause problems. So what should you do with the four unused data lines when the display is used in 4-bit mode? This question arose when a circuit was submitted to us where D0-D3 where tied directly to GND (the same applies if it was to +5 V) to stop the problem of floating inputs.

The LCD module was driven directly by a microcontroller, which was on a development board for testing various programs and I/O functions. There was a switch present for turning off the enable of the display when it wasn’t being used, but this could be forgotten during some experiments. When the R/Wline of the display is permanently tied to GND (data only goes from the microcontroller to the display) then the remaining lines can safely be connected to the supply (+ve or GND). In this application however, the R/Wline was also controlled by the microcontroller. When the display is initialised correctly then nothing much should go wrong. The data sheet for the HD44780 is not very clear as to what happens with the low nibble during initialisation.

After the power-on reset the display will always be in 8-bit mode. A simple experiment (see the accompanying circuit) reveals that it is safer to use pull-down resistors to GND for the four low data lines. The data lines of the display are configured as outputs in this circuit (R/Wis high) and the ‘enable’ is toggled (which can still happen, even though it is not the intention to communicate with the display). Note that in practice the RS line will also be driven by an I/O pin, and in our circuit the R/W line as well. All data lines become high and it’s not certain if (and if so, for how long) the display can survive with four shorted data lines. The moral of the story is: in 4-bit mode you should always tie D0-D3 via resistors to ground or positive.

Author: L. Lemmens
Copyright: Elektor Electronics

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Infrared Remote Control Extender

This ultra-simple remote control extender is ideal for use with a hidden video recorder. The recorder is a Panasonic NV-SD200 and is used as part of a camera surveillance system. A PICAXE-08-based circuit is used to detect events and control the recorder. It also flashes a LED near the monitor to indicate the number of events since last viewing.

Strangely, the NV-SD200 model refused to work with a number of commercial infrared remote control extenders, hence the need for this design. As a bonus, it uses less power than a traditional extender (no plugpacks) and the remote can still be used in the normal manner.

As shown, an additional 5mm infrared LED is mounted directly in front of the equipment to be controlled. This is cabled back to a convenient location near the monitor and terminated in a 3.5mm plug.

To modify the remote control unit, break the circuit to the anode of the existing infrared LED and wire in a 3.5mm headphone socket. In most cases, the LED will be accessible without dismantling the circuit board. The purpose of the socket is to allow the existing infrared LED to operate normally when the jack is unplugged.

If the socket won’t fit inside the case, then a very short flying lead with a moulded in-line socket can be used instead. By using light-duty figure-eight cable, the transmitting LED could be 30m or more from the hand-held remote control without problems.

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IR Remote Control Extender Circuit Diagram

An Infra Red wired Repeater circuit to control appliances from a remote location.

IR Remote Control Extender Circuit Diagram 

Parts List:
R1: 1k Resistor (1)R2: 3.3k Resistor (1)
R3: 10k Resistor (1)
R4: 15k Resistor (1)
R5: 2k2 Resistor (1)
R6: 470R Resistor (1)
R7: 47R Resistor (1) 0.5 Watt
PR1: 4.7k Preset (1)
C1,C3: 47u Elect(2)
C2: 1n Polyester 5% or better (1)
C4: 100u Elect(1)
Z1: 5V1 Zener (1)
Q1: BC549C or BC109C or 2N2222 (1)
Q2: BC337 or BC549 or ZTX450 (1)
IC1 : TSOP1738
IC2: 555 or 7555 (1)
LED1 5mm RED (1)
LED2,3 IR diode TIL38 or similar (2)

Alternatives to IC1 :
Everlight IR receiver module ELIRM 8621
Harrison electronics IR1
Vishay TSOP 1838
Radio Shack 276-0137
Sony SBX 1620-12
Sharp GP1U271R  

Notes:

The signal emitted by an IR remote control contains two parts, the control pulses and a modulated carrier wave. The control pulses are used to modulate the carrier, a popular modulation frequency being 36 and 42KHz. The signal is radiated by an IR diode, typical wavelengths in the 850 and 950 nm region of the electromagnetic spectrum. Although this light is invisible to the human eye, it can be seen as a bright spot with a camcorder or digital camera.

In this circuit, the TSOP1738 IR module removes the carrier leaving only the slower control pulses ( 1 - 3KHz) which appear at the output. R1, C1 and Z1 form a smoothed 5 Volt supply for the IR module. Under quiescent conditions (no input signal) the output of the IR module is high. Transistor Q1 will be on, resulting in a low collector voltage, restting the 555 oscillator. Q1 also acts as a level shifter, converting the 5 Volt output signal to 12 Volts for the 555 timer. When an IR signal is received, decoded control pulses turn Q1 off and on. Each time Q1 turns off, pin 4 of the 555 timer goes high and an oscillation will be produced for the duration of each data pulse.

The 555 is wired as an equal mark/space ratio oscillator, the timing resistor R4, being connected back to the output of the timer, pin 3. The timing capacitor C2 is the other component in the timing chain. The pulse duration at pin 3 is defined as:-

T = 1.4 R4 C2

As the timing is crucialthe capacitor should have a tolerance of 5% or better and the power supply should be regulated. To allow for tolerance in components a 4k7 preset resistor is wired in series with R4. This adjustment allows R4 to be 15k to 19.7K creating output pulses of 21us and 27.58 us. As frequency is the reciprocal of periodic time then the oscillator adjustment is from 36.2Khz to 47KHz, allowing fine tuning for almost any appliance.

The final output stage uses a BC337 transistor in emitter follower. The output pulse will not be inverted, and the current through the IR photo emitters is around 30 mA dc. This is of course an average value, measured with a digital multimeter. The red led as always, is a visible indication that an input signal has been received. The circuit may be modified to use a fixed resistor in the timing chain as shown below. In this example a voltage regulator is also recommended to prevent changes in supply voltage altering the output pulse.

Setup and Testing:
Remove LED 2 and 3 and apply power. With no input signal LED 1 should be off. Press a button on a remote control in the same room as the circuit. LED 1 should flicker. If all is well, connect LED's 2 and 3 and point them in the direction of the appliance (TV or VCR etc). The cable to the LED's can exceed 100 metres if necessary, ordinary loudspeaker cable or bell wire is suitable. Set preset PR1 midway initially, it should work for all equipment. Most equipment is tolerant to within 5% so if you have for example a video that works at 42kHz and a TV that works at 38Kz tuning the modulation to 40KHz should allow both devices to operate. Any troublesome equipment, for example an Echostar receiver repeatedly press abutton on the handset while tuning PR1, you will find that it operates at some point. One IR LED may be used in place of LED2 & 3, but if there are two appliance in the same room, but in different locations, LED 2 can be aimed at a video, while LED3 aimed at a CD player for example. Below is how I discretely placed a photo emitter and plastered it directly into the wall:

Modifications:
An alternative output configuration is shown below. This uses a MOSFET to replace the original BC337 transistor. My thanks to Pete Griffiths for this modification and diagram.

 
Compatability:
If you make either the Mark 3 or 4 circuit please let me know if it works and the make and model of your remote control. I will add this to the database of compatible handsets below:-  link

Aiwa RC-ZVR01
Denon RC 554
Denon RC 921
Denon RC 924
Echostar T22605AA-00 * troublesome required careful tuning of PR1 to work
Kameleon One for all remote (URC-8060) Goodmans 97P1R2CPA1
Grundig SRC2
JVC LP20878-002
Matsui 28WN04
Mitsubishi 290P103A10
Mitsubishi EUR647003
NAD HTR2 (multi remote)
One for All 9910
Panasonic EUR511200
Philips RC6512
Pioneer AXD7323
Pioneer DV444
Pioneer VXX2801
Radioshack 1995
Saisho VR3300X
Sony RM-533
Sony RM-887
Sony RMT-V240
Sony RM-S325
Sony RM-DX50
Sony RM-U215
Sony RM-839
Sony RM-SCEX1
Sony RM-S336
Sony RM-D43M
Sony VCR
Technics EUR64713

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Programmer AVR Your USB Circuit Diagram

This Simple Programmer AVR Your USB Circuit Diagram is a design of a programmer Atmel AVR microcontrollers that uses a driver firmware that makes the programmer is attractive to many amateurs. Another advantage of this programmer and becomes popular is because it is officially included and supported in WinAVR.



AVR programmer via USB


You can download PCB and various circuit configurations directly from the website http://www.fischl.de/usbasp/.

Scheme

PC connection -> USBasp -> Target Board

 Programmer AVR Your USB Circuit Diagram

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Tester for USB communication ports Circuit

This circuit is a simple test of USB ports, it is a circuit very useful for anyone working in the field of computer science. To be "stuck" in the PC USB port or an information display Notebook USB device not recognized, just after the yellow LED flashes 3 times, and since it is not a normal USB device, the connection is not established, and micro displays an error message.

Tester for USB communication ports Circuit Diagram

List of Components
1 Red LED
1 Led Yellow
1 Green LED
3 per 1k 1/8W Resistors
1 USB connector male

Simple Test for USB communication ports

Indications of LEDs when lit:
Red - Polarization USB port was mounted inverted
Yellow - Wire USB port data were linked inverted
All Deleted - No power to the USB port
Green and yellow lights flashing 3 times when turned on - Normal Operation

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Modem for Digital Modes Circuits Diagram

This is the Modem for Digital Modes Circuits Diagram. Ham Com is a modem for almost all types of digital transmission for radio amateurs. It can be used to RTTY, ASCII, NevTex, Sitor, Amtor, Fec, CW, FSK, etc.. The modem is simple and can even be used for receiving faxes and SSTV wx-using JV-FAX software.

 Modem for Digital Modes Circuits Diagram

To use this modem, you need a PC with serial port, Software HamCom and radio equipment.

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Project of Computer Joystick Circuit Diagram

This circuit Joystick computer is very simple and can be used on any PC that has the connection to Joystick. The original circuit uses a 74HC04, but can be replaced by a pin 4049 by changing the voltage, or any other multivibrator circuit, one or even two transistors 555.

 Computer Joystick Circuit Diagram

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