The Temperature Candle is a relatively simple design which essentially boils down to a 8-pin microcontroller, a temperature sensor and voltage reference and a RGB LED on a 1.5″ diameter PCB – the same size as a standard votive candle. The micro flickers the LED like a candle at a color determined by the ambient temperature. The color gives an indication of the room temperature in reference to the recommended sleep time temperature for
babies to reduce the risk of SIDS (Sudden Infant Death Syndrome).
The candle can also blink the temperature by pressing a reset button on the PCB.
This should be a relatively cheap kit and it uses all thru-hole components so it should be easy to assemble. Using a simple micro, it can also be a good introduction to microcontrollers, and is designed with a jack to connect to Microchip’s Pickit 3 programmer / debugger.
You can see more information and look at all the design files on its project page.
The Temperature Candle – [Link]
To drive a 3×3 mm sized LED with a current of 1.5A was unthinkable till lately. OSLON Square enables it, thus providing a free hand in designing powerful and compact LED applications.
New OSLON Square series is suitable for outdoor and indoor LED applications, as well as for exceptionally compact designs. At the first look, OSLON Square is similar to the OSLON SSL series. The difference is in the substantially larger chip, what enabled to double a maximum driving current.
Advantages / Features:
- driving current up to 1.5A
- 3×3 mm ultra compact dimensions
- lifetime of more than 50000 hours
- excellent corrosion resistance
- suitable even to humid environment
- excellent color consistency thanks to a fine binning
- thermal resistance RTHJS only 3,8K/W
But the power and ultra compact dimensions are not the only advantages of OSLON Square. Among another features also belongs robustness – the SMT package doesn´t contain silver, that´s why it´s highly resistant even to the most humid environment. White reflective layer contributes to better usage of the reflected light and helps to efficient usage of every lumen during the whole lifetime. Thanks to a very low thermal resistance of the package, lifetime of over 50 000 hours can be easily obtained, even at high driving currents. Resulting low operational temperature helps to reach high light output and a long lifetime. Fine binning system and usage of the latest phosphor conversion technology ensure perfect color consistency and stability.
Four basic groups are available:
- EC, white with a balance of luminous flux and CRI min. 80.
- PC, neutral white with a maximized luminous flux, while keeping a very good CRI min. 70. Typical brightness is 245 lm/ 5000K/ 700mA.
- Streetwhite, cold white with a maximized luminous flux with CRI min. 65.
- EQW, intended for technical and industrial lighting with a maximum energy saving (color coordinates Cx=0.37, Cy=0.44).
Further information will provide you the OSLON Square flyer and application details. It is worth to mention, that OSLON Square neither other power LEDS without a heatsink should never be tested without a proper soldering to a cooling baseplate/PCB – because of a very small thermal capacity a tested LED would be destroyed within few seconds.
New LED OSRAM OSLON Square withstands up to 1.5A – [Link]
- Supply voltage: Between 11 and 15V (MAX) CC
- Adjustments PWM between 1% to 98% typical
- 5A output current (with cooling)
Led Dimmer using TL081 – [Link]
Instructables user cold_steel writes: [via]
This is probably one of the most used tools in my workshop, the “extra hands”. It is the ultimate tool for soldering and prying in the very small range. But over time I found that I do not have enough light on my work when using this tool. Actually all the benefits you would expect from having a magnifying glass for easy reach are over shadowed by the shadow cast by the rim. And honestly I haven’t managed to position my desk lamp in such a way that I was able to conveniently light my tiny work. So I decided it is time for some upgrades.
As usual you will find all G-code and other files included so you can reproduce this easy on your own CNC machine.
Ring Light for Helping Hands – [Link]
We incorporated among standard stock types the dot matrix LED display Kingbright TC12-11 with the height of 30.6mm. Hyper red color (630nm) and a high luminous intensity provide a contrast image.
TC12-11SRWA with 5×7 dots can be conveniently used especially in indoor applications, where it will provide an excellent readability at various ambient light conditions. Display can also be used for outdoor applications, excluding places on a direct sunlight, where the display legibility can be substantially decreased.
High light output, typically 82mCd/10mA and white diffused lens ensure a very good visibility even from higher viewing angles. Display features almost a linear luminous intensity / current characteristics in a range from 0 to 20mA, that´s why it is fully usable even for low power applications. Similarly like almost all dot matrix displays, even TC12-11 is designed in a way that when placed in a row, we will obtain a continuous row with homogenous spacing between dots. That´s why it is possible to display even symbols wider than 5 points and naturally a moving text.
TC12-11 has a common cathode (in a column), available are also versions with a common anode (in a row) and also various colour versions.
Universal 1.2″ LED dot matrix display – [Link]
Seven segment LED displays are a very popular mean of displaying numerical information and finds application in front panel display boards of microwave ovens, washers and dryers, digital clocks, frequency counters, and many other gadgets. Compared to the LCD displays, the seven segment LED displays are brighter and provide a far viewing distance and a wide viewing angle. However, the downside is they are resource-hungry. It requires at least 12 I/O pins of a microcontroller to drive a standard 4-digit seven segment LED module. Consequently, their use with low pin-count microcontrollers (such as PIC12F series) is not practically feasible. Here’s a solution for that. The following 4-digit seven segment LED module features a serial interface that requires only 3 I/O pins of a microcontroller and provides full control of all digits and decimal points .
Serial four digit 7-segment LED display module – [Link]
The Binary Burst clock shows the time with LEDs:
The clock uses 3 LEDs on each spire to count up to 5 in binary. The hours are displayed by the middle LED in RED (Its a Red/Blue bicolor, the others are just blue). Video, and links to the board and code repository are included in the post. Check out a demonstration video below. There’s also a time-lapse soldering video of build. [via]
Binary Burst clock ticks away the time with LEDs – [Link]
A CREE MCE4-LED mounted on a STAR PCB. Available in cold white, warm white and RGBW versions, can be powered by a constant current of up to 700 mA – 430 lm
A CREE XP-G LED mounted on a STAR PCB. Available in three shades of white and powered by a constant current up to 1050 mA. Matching lenses of 7°, 15.5° or 25° beam angle are available as accessories.
Giorgos Lazaridis writes:
Some time ago i published a theory page regarding the LED driving and controlling methods. These methods were all linear regulators, very simple to make but very inefficient -in terms of power consumption- for high current applications. The idea was to use this theory page as an entrance level for the SMPS LED drivers.
The first SMPS (Switching Mode Power Supply) LED driver that i made is a Buck-Regulating LED Driver using a chip from Allegro Microsystems, the A6210. I was provided some samples from Farnell for testing and prototyping, along with some other cool staff. Do not forget to pay a visit to Farnell on-line store and Element14 website.
The A6210 can drive up to 3A load with constant current, with switching frequencies up to 2 MHz and supply voltage from 9 to 46 volts. It has additionally an optional PWM input to control the brightness of the LED. The sense voltage is limited to 0.18 volts for higher efficiency, since the power dissipation on this sense resistor is minimal. I will be using a 10-12V 1A 10 Watt LED, powered from 24 VDC supply.
High Efficiency High Current LED Buck Driver using the A6210 – [Link]