Battery-operated equipment often will benefit from a power-on indicator. The indicator, however, can waste significant power. In situations where a low-duty-cycle blinking indicator provides an adequate indication of the power being turned on, the simple circuit described here should prove useful. Figure 1 Q1 and Q2 function as a current source and push a constant […]
Low-duty-cycle LED flasher keeps power draw at 4 mW Read More »
In the Hammond 1553 enclosures series now can be found also types with a sufficient space for a keyboard and display. Series of ergonomic handheld enclosures – 1553is familiar to many of you. All types from this series provide a reliable grip thanks to a pleasant side overmold, they feature the same shape and they´re
HAMMOND 1553T enclosures – keyboard and display in your hand Read More »
For a long time I wanted to enter the 21st century by stopping using NiCad or NiMH batteries and upgrading to Lithium accumulators as they provide more power per volume and are cool in general. Constant flow of obsolete cell phones provides a nice source of reasonably high-performance batteries for free – I felt compelled
Open source Lithium battery charger modules Read More »
RS Components and Premier Farnell/element14 have Model A Raspberry Pis in stock as of this morning. (See the Where To Buy area on the right side of the page for links.) For the first tranche of orders, Model A will only be available in Europe. We’ll lift this restriction very soon so the rest of the
Smaller Raspberry Pi costs under $25 Read More »
The 12F series of PIC microcontrollers are handy little 8-pin devices designed for small embedded applications that do not require too many I/O resources, and where small size is advantageous. These applications include a wide range of everyday products such as hair dryers, electric toothbrushes, rice cookers, vacuum cleaners, coffee makers, and blenders. Despite their
Revised version of the PIC12F microcontrollers breakout board Read More »
Sealed Lead Acid batteries are often used in amateur radio as a convenient power source for radios, since amateur radio equipment has standardized on 12.6V. The Cal Poly Amateur Radio Club enjoys a steady source of donations of slightly used SLAs, so I got a few of them with need for a battery charger. Since the
555 based constant current lead-acid battery charger Read More »
The objective of this project is to build an Arduino voice shield to empower thousands of voice related applications! All this mostly thanks to an integrated ISD1790PY chip. This particular voice/TTS feature can be useful to integrate voice messages in alarm systems, to implement generic I/O controls in home automation or even in home security
A Voice Shield for Arduino – Give Voice to your Ideas! Read More »
In Day 3 tutorial, we learnt basics of seven segment LED displays and discussed about a time-division multiplexing technique that reduces the number of required microcontroller I/O pins to drive multiple seven segment LED displays. Today we will move a step further and discuss about a serial interface (SPI) for driving 8 seven segment LED displays. The technique
Netduino and MAX721 interfacing for driving seven segment LED displays Read More »
The following is important because with flexible organic photovoltaic cells, we are nearing a new era of development for practical solar-based solutions can be implemented with clever usage of these devices. Efficiency needs to be higher, but technology is progressing in the right direction and a breakthrough is inevitable. Heliatek announced a record breaking 12.0%
New world record for organic solar technology with a cell efficiency of 12% Read More »
DIN rail terminal blocks using the CAGE CLAMP®S spring clamp bring a simpler installation even without tools and up to 30% saving of space. Since 1977, when company Wago launched screwless terminal blocks on the market, have the terminal blocks using this system earned a high popularity. During many years, the Cage Clamp® system proved
Wago TOPJOB ® S – nowadays standard in installations? Read More »
