Been awhile since I posted anything here, so I thought I’d use this post to give some more detail on a project I just completed. The whole idea was to create a giant meter to show website response time almost like a speedometer would. The result is something that’s both fun to watch and provides a meaningful ‘heartbeat’ of current status. After several revisions and different designs along the way, I ended up with what you see here.
Server response time meter - [Link]
by Maurice O’Brien @ edn.com:
Wideband communication systems usually require an ultra-low noise regulator to power the VCOs and PLLs. The regulator must also be able to reject any ripple presented at its input. In a typical system, an ac input is converted to an isolated dc supply rail, –48-V, for example. This rail is then converted to an isolated 12-V or 5-V system rail that powers the main components in the communication system.
Ultra-low noise linear regulators for powering PLL/VCO and clocking ICs - [Link]
The MCP6V01 auto-zeroed op-amp features an ultra low offset voltage (VOS) and high common mode rejection ratio (CMRR), which makes it applicable to temperature measurement. The MCP6V01 thermocouple auto-zeroed reference design demonstrates how to measure electromotive force (EMF) voltage at the cold junction of the thermocouple in order to accurately measure temperature at the hot junction.
The difference amplifier is implemented using the MCP6V01 and 0.1% tolerance resistors. It amplifies the EMF voltage at the cold junction of the thermocouple. The MCP9800 senses temperature at the type K thermocouple’s connector. It should be located as close as possible to the connector on the PCB. This measurement is used to perform cold junction compensation for the thermocouple measurement. The MCP1541 provides a VREF (4.1V) to the internal 10-Bit ADC of the PIC18F2550 and sets the reference voltage for the difference amplifier. The CVREF is the internal comparator voltage reference of PIC18F2550, which is a 16-tap resistor ladder network that provides a selectable reference voltage. The MCP6001 buffer amplifier eliminates the voltage reference output impedance problem and produces the voltage VSHIFT.
The 2nd order RC low-pass filter that is implemented in this circuit can remove the high frequency noise and aliasing at the ADC input. The ADC of PIC18F2550 completes the analog-to-digital conversion. The data will be transferred to the PC using the USB interface. The thermal management software on PC is used to perform data display to show the real-time temperature and apply cold junction compensation and data linearization to determine the actual temperature of the thermocouple’s hot junction (weld bead).
Thermocouple Auto-Zeroed Reference Design - [Link]
Long term reliable contact without interference, creaking and hum, moreover in a beautiful coat – these are the Neutrik / Rean connectors.
Connectors have in general one interesting feature – there are many similar or almost the same connectors on the market. Audio connectors are not exception in this. Even though they look the same, many times there are huge differences in price and mainly in quality. If we supposed, that every producer designs and makes his products likewise responsibly, then the cheaper one should be probably a good choice. Naturally, in praxis it isn´t so.
A real difference between a quality and a low-class connector can be known only at a close-detail investigation and comparison, and ideally after a real testing in praxis.
Quality audio connector must be made of quality materials and also with a high precision. Naturally, if a producer wants to achieve success on a market, it´s often simply impossible to use a too expensive connector, which would over-price the whole device.
That´s why you can find in our store the Neutrik / Rean connectors offering a high-end class for a very reasonable price. Company Neutrik specializes already for almost 40 years in audio connectors and in general connectors for audio/ video studios, equipment of concerts (backstage) and similar, that´s why also in loudspeaker connectors, power supply, Ethernet,…
In the Neutrik products can also be found connectors Rean representing even more affordable price level while maintaining a very high quality. Already a short look at details of Neutrik/ Rean connectors will tell us, that we´re dealing with precision connectors. A matter of course is a detailed documentation with an exact description of electrical features and materials used. A comprehensive overview about available types will give you the Rean catalogue and the Neutrik catalogue (22MB). To many sophisticated connectors like for example NYS373 there are also available assembly instructions.
Uncompromising quality audio connectors for a compromising price - [Link]
by Beke András @ bekeband.hu:
An black and white monitor needs to improve and repair from about 1990-th. The repair of device was not difficult but it caused troubles for the testing and setting of the monitor. We have a pattern TV generator, but this instrument are produce on the composite video signal for monitor. Unfortunately this monitor is demand not compozite signal instead of horizontal sync, vertical sync, and lightning signal. (video signal). Whereas the monitor host machine is not available – in fact I don”t know exactly what kind of equipment, perhaps a kind of mass spectrometer or something -, we need necessary a appropriate video signal source.
Video generator with PIC - [Link]
by Patrick Hood-Daniel @ youtube.com:
In this video, I introduce the concept of I2C or TWI and explain the common use of the protocol and how to set it up. This is part one. Part two will delve into the circuit that we will use for the example.
I2C/TWI (Two Wire Interface) Tutorial - [Link]
Minimum noise, easy speed control and a high power, those are another reasons why to decide for GreenTech EC fans from EBM-Papst.
A term „EC fan“ (electronic commutation) is generally used to mark energy-saving AC fans. In fact, these are DC (brushless) fans with AC/DC module and other electronics. EC fans reach up to 90% efficiency and they consume 50% less energy than traditional AC fans.
At the same time, a typical „50Hz“ motor noise is eliminated at EC fans and practically the only noise source is aerodynamic noise depending on overall fan design.
A good example of a modern fan is for example the type G1G140-AW31-42 i.e. radial (centrifugal) fan with 140mm diameter. Efficient motor with a „Soft start“ function enables to control fan speed through a DC input (0-10V) or PWM. To check a proper function, the fan also features „Tach“ output (2 pulses / revolution) as well as locked motor protection.
Thanks to the built-in electronics, at cyclic use it´s recommended to switch-off the motor through a control signal, not by switching-off main power supply.
G1G140-AW31-42 is suitable for a continuous operation (S1) and can be mounted in any position. It´s used for example for building ventilation.
Detailed information will provide you the G1G140-AW31-42 datasheet.
Modern EC fans are able to save up to 50% of energy - [Link]
by DIY Hacks and How Tos @ instructables.com:
The Clapper was a popular gadget in the 80’s and 90’s. It let you turn appliances on and off just by clapping. This can be pretty useful, but it has some limitations. First there is the problem of loud noises accidentally turning the lights off. Also, you can’t control multiple outlets independently of each other.
So I decided to make programmable version of the Clapper using an Arduino microcontroller. The Arduino lets you set codes for each outlet. This eliminates false triggering and lets you control multiple outlets independently. Your lamp could be turned on and off with one clapping pattern and your fan could be controlled with another pattern.
Sound Activated Outlet - [Link]
by batkin @ instructables.com:
Get in the mood with some fairly simple ATTiny85 based DIY color shifting lamps!
Color Changing Mood Lamp - [Link]
by Jan_Henrik @ instructables.com:
Hi, in this Instructable I want to show you how to create your own diffusor for a LED Matrix. To do this we will use a 3D printer and OpenSCAD. In this tutorial I will use a LOL-Shield by Jimmie ( http://jimmieprodgers.com/kits/lolshield/ ) also I will explain, how to design a diffusor for different matrix sizes and shapes.
As I recently was at the 31C3 in Hamburg i got a LOL-Shield from Jimmie. This shield is holding 126 LED´s which are Charlieplexed. After coding some animations and a game on it I thought that the LED´s where too bright. Because I wanted to keep the greyscale ( dimming ) of the matrix I decided to design and build a diffusor.
How to make a diffusor for your LED Matrix - [Link]