Electronic meters compared to traditional mechanical solutions in use offer several additional advantages to the utility market. The metering utilities that can be replaced are gas, water and electricity.
On the behalf of elxproject.com team I would like to express my warm wish of New Year 2011 for you all our visitors and valuable members. May this new year fill your life with sweetest memories to cherish forever. And warmth of those whom the heart holds close, Filled with joyous moments and lots of happiness, for you and your dear ones A very Happy New Year.
This FM transmitter circuit uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built around transistor 2N3866 (T4). A condenser microphone is connected at the input of the oscillator.
This circuit saves both time and electricity for students. It helps to prevent them from dozing off while studying, by sounding a beep at a fixed time interval, say, 30 minutes. If the student is awake during the beep, he can reset the circuit to beep in the next 30 minutes. If the timer is not reset during this time, it means the student is in deep sleep or not in the room, and the circuit switches off the light and fan in the room, thus preventing the wastage of electricity.
This circuit displays the Hexadecimal equivalent of a 4 bit Binary Number. The number is displayed on a 7 Segment LED display. There are many Binary to 7 Segment decoders out there, such as the CD4511, DM74LS47, SN7447 and the DM9368. All of which have attractive features, but none have all of them in one package. Another downside is many only display 0 - 9 with few displaying all Hexadecimal digits (0 - F). With many of these chips obsolete and hard to find, my Binary to 7 Segment Decoder is a versatile substiute.
We are very glad to inform to all the users of this website that we have successfully completed two years serving the electronics students all over the world. We would like to thank to all the users that we have been a part of it. We expect that in coming future more and more users will be benefited from this website. We promise that we are devoted to update the information timely and provide you all more information of new discoveries in electronics.
On the behalf of elxproject.com team I would like to express my warm wish of New Year 2010 for you all our visitors and valuable members. Hope this year brings you all the exciting success in your life.
Communication jamming devices were first developed and used by military. This interest comes from the fundamental objective of denying the successful transport of information from the sender (tactical commanders) to the receiver (the army personnel), and vice-versa. Nowadays, mobile (or cell) phones are becoming essential tools in our daily life.
This circuit is a simple two transistor (2N2222) FM transmitter. No license is required for this transmitter according to FCC regulations regarding wireless microphones. If powered by a 9 volt battery and used with an antenna no longer than 12 inches, the transmitter will be within the FCC limits.
You might have seen many videos around you tube showing off crazy LED cubes, forming 3-D structures etc. But haven't find anything that explains how this is being done. Well searching over internet i found this great project made using a PIC 16F688 microcontroller used to control a 5x5x5 LED matrix cube.
The LED cube is made up from 125 LEDs arranged into 5 layers of 25 LEDs each. The display itself is multiplexed so instead of requiring 125 connections it requires one to each of the five layers and 25 to each LED in a layer making a total of 30. The cube is refreshed by a software interrupt routine with each layer active for 2ms, so the entire cube is refreshed every 10mS (100Hz). This results in a display with no visible flicker.
Only 8 I/O lines are needed to control the LED drivers for the cube which allows a tiny 14 pin PIC 16F688 microcontroller to control the whole cube. This micro has an internal 8Mhz clock and 4Kwords of program memory.
Plate batteries for old tube radios are today only available with difficulty. However, step-up controllers for low DC voltages are everywhere. The circuits of these ICís are, however, affected by disadvantages and complex wound inductance are needed. A further disadvantage of this solution is the transducer frequency; poor placing can cause audible interference.