IC Blog Center
Index 49
DELPHI FOR ELECTRONIC ENGINEERS: Part 2 - Programming a calculator （2）
Published:2011/8/22 21:34:00 Author:Li xiao na
By Herman Bulle Processing layer Now you have to put the application lo work. Every process in the calculator, such as adding two numbers, consists of four steps: - entering the first number - storing the operation - entering the second number - starting processing by pressing the = button A number is formed by pressing the button tor the first digit ... (View)
View full text | Comments | Reading(378)
DELPHI FOR ELECTRONIC ENGINEERS: Part 2 - Programming a calculator （1）
Published:2011/8/22 21:04:00 Author:Li xiao na
By Herman Bulle In the first installment of this series, we introduced the Delphi programming environment and described several examples that illustrate how to program in Delphi. In this installment, we take a more detailed look at the design of a somewhat more serious program. Our project here is to construct a simple pocket calculator in software. In next month’s installment, it will ... (View)
View full text | Comments | Reading(1713)
Replacement for the Battery: A 90-volts inverter for vintage radios
Published:2011/8/22 2:55:00 Author:Li xiao na
Prof. Martin Ohsmann Valve circuits and radios in particular are graced by vast crowds of enthusiasts. If you want to keep your prize vintage radio as authentic as possible while actually using it from time to time you need a HV (high voltage) battery or its electronic equivalent. One of the most popular types of vintage radio running off a high voltage (HV) bat... (View)
View full text | Comments | Reading(2484)
Walking Bug: A robot with servo-powered legs 3
Published:2011/8/22 2:25:00 Author:Amy
A. Vreugdenhil Construction On the printed circuit board designed for the Walking Bug (Figure 2) you first mount the passive parts, that is, the resistors, capacitors, ceramic resonator, connectors and miroswitches. Next, continue by fitting the l.EDs and the microcontroller (preferably in an IC... (View)
View full text | Comments | Reading(1319)
Free Internet must exist
Published:2011/8/22 2:20:00 Author:Li xiao na
By David Daamen Of course, there’s no such thing as free Internet, but surely that does not mean you have to pay the bill? Today, with a little ingenuity and some experimentation it is often possible to tap into a neighbor’s wireless network, if it is not, or not sufficiently, protected. Many people u... (View)
View full text | Comments | Reading(445)
Walking Bug: A robot with servo-powered legs 2
Published:2011/8/22 2:09:00 Author:Amy
A. Vreugdenhil Backwards You may have seen on the photographs that our Walking Bug has two ’antennae'. Two stiff wires are secured to microswitch levers, allowing the microcontroller to detect if the Bug has run into an obstacle. If that is the case, the program branches out of the main loop into a subroutine ’Back’ causing the robot to walk backwards for a while. The ’... (View)
View full text | Comments | Reading(390)
Walking Bug: A robot with servo-powered legs 1
Published:2011/8/22 1:52:00 Author:Amy
A. Vreugdenhil Making a robot walk instead of drive around on wheels can be a daunting task. The author of this Walking Bug came up with a remarkably simple solution. Although our robot does not stand upright on two legs, it can actually walk using just two servos and a minimum amount of electronics. The power of the design is. of course, found in the combination of these two ele&sh... (View)
View full text | Comments | Reading(1078)
Step-up Converter for White LEDs
Published:2011/8/22 1:43:00 Author:Li xiao na
By Dirk Gehrke White LEDs are increasingly used for lighting applications in battery-powered equipment. To cope with the effects of a fluctuating supply voltage, a constant-current source is a must. There are now countless applications where while LEDs (light emitting diodes} are used as (background! light sources. As examples we could mention ICD or keyboard backlighting. Alter... (View)
View full text | Comments | Reading(598)
Remote Thermometer for the PC: PC data logger with email alerting 3
Published:2011/8/21 22:12:00 Author:Amy
Cyril Jouanjan Viewing the results After you have entered the address and name of the sensor and activated the acquisition, click OK and you will return to the main window (Figure 4). This window is updated at the same rate as the acquisition period entered earlier. If the sensor has been detected, the corresponding name is shown on a flashing green background, with the temperature ... (View)
View full text | Comments | Reading(493)
RF Detection
Published:2011/8/21 22:01:00 Author:Li xiao na
By David Daamen WiFi detectors are small gadgets that claim to detect wireless access points for computer networks. The effectiveness of these devices is already covered in many Internet articles, but here you will find out exactly how they work. To begin with, we opened the first device we had to hand; see Figure 1 (Kensington ’WiFi Finder’). It was immediately app... (View)
View full text | Comments | Reading(1026)
Remote Thermometer for the PC: PC data logger with email alerting 2
Published:2011/8/21 22:00:00 Author:Amy
Cyril Jouanjan Sensor connections The sensor used here, the DS1621, already contains practically all the necessary components. The IC also contains a built-in thermostat, but that functionality is not used in this project. The accuracy of the DS1621 is of the order of 0.5°C without the need for any special calibration. The measuring range spans from -55°C to +125°C and the... (View)
View full text | Comments | Reading(1303)
Remote Thermometer for the PC: PC data logger with email alerting 1
Published:2011/8/21 21:47:00 Author:Amy
Cyril Jouanjan With the aid of a PC and intelligent temperature sensors it is very easy and quick to assemble a professional temperature data-logger. Using e-mail, up to four temperatures can be monitored from a distance. The sensors are simply connected to the PC parallel port. In this article we describe a system that measures and records tempera* lures. The heart of the system ... (View)
View full text | Comments | Reading(509)
HIGH-END POWER AMP-High-class watts （6）
Published:2011/8/21 21:46:00 Author:Phyllis
By Ton Giesbets Don’t solder the driver transistors, output transistors or quiescent-current transistor to the circuit board just yet. The leads of these transistors must first bent to the right spacing, so they can rest properly on the heat sink without any mechanical strain after being fitted. That is described in detail under ’Final assembly’. Next comes the (View)
View full text | Comments | Reading(1467)
LED Bedside Lamp: with turn-off delay
Published:2011/8/21 21:36:00 Author:Li xiao na
By Eduard Heger If you are not lucky enough to have access to expensive test gear then lamp circuits using LEDs offer a good chance of success and allow a little bit of electronic experimentation. simple but useful addition to the bedside table. The lamp is activated either by pressing a push button or automatically when the... (View)
View full text | Comments | Reading(1618)
HIGH-END POWER AMP-High-class watts （5）
Published:2011/8/21 21:29:00 Author:Phyllis
By Ton Giesbets Power supply A separate printed circuit board has been designed for the power supply (Figure 4). It just fits into the enclosure between the transformers. The power supply design is quite conventional, with a standard 80-VA toroidal transformer, rectifier, and electrolytic smoothing (View)
View full text | Comments | Reading(3217)
HIGH-END POWER AMP-High-class watts （4）
Published:2011/8/21 21:11:00 Author:Phyllis
By Ton Giesbets IC1 is a fast dual opamp (type AD827). Here ICla is configured as a difference amplifier that compares the two signals at its inputs. R8 and R9 attenuate the loudspeaker signal by a factor of two (10.5÷2). This means that IClb only has to provide a gain of 3.5 (10.5 ÷ 2 ÷ 1.5). The gain of ICla can be adjusted using PI to compensate for variations in component values. In the... (View)
View full text | Comments | Reading(516)
HIGH-END POWER AMP-High-class watts （3）
Published:2011/8/21 21:02:00 Author:Phyllis
By Ton Giesbets To protect the loudspeakers against output offset voltage transients that may occur when the mains voltage is switched on, a switch-on delay is provided for the output relay. The delay time is approximately 6-7 seconds. The state of the relay depends on the supply voltage for the final amplifier, rather than the (View)
View full text | Comments | Reading(1346)
Marconi TF1152 RF Wattmeter
Published:2011/8/21 20:46:00 Author:Li xiao na
By Jan Builing In line with this month’s locus on all things Wireless I am coveting a vintage instrument that has given me many years of excellent service and peace of mind at o very small investment indeed. If you like to work with (View)
View full text | Comments | Reading(3134)
Frequency Spectrum from DC to 30 GHz in 4 pages 4
Published:2011/8/21 20:44:00 Author:Amy
Paul Goossens Galileo A number of European countries are collaborating on a project to create a network similar lo GPS. Just like GPS this network makes it possible lo determine your position very accurately. This new system, christened Galileo, also uses a network of satellites in space. It is anticipated that this system will be even more accurate than the current GPSI. <... (View)
View full text | Comments | Reading(423)
HIGH-END POWER AMP-High-class watts （2）
Published:2011/8/21 20:43:00 Author:Phyllis
By Ton Giesbets As can clearly be seen, all of the operating points in the amplifier are directly dependent on these two current sources, so we gave particular attention to their design. The reference voltages for the current sources are provided by flat LEDs, which in turn are operated at reasonably constant currents provided by a ... (View)
View full text | Comments | Reading(487)
| Pages:49/114 At 204142434445464748495051525354555657585960Under 20 |