In a very affordable price level, a multimeter able to measure a DC current without interruption of a measured circuit can be found.
UT203 UT203 from company UNI-Trend belongs to a category of clamp multimeters. A main reason to buy a clamp multimeter is usually a requirement to measure current flowing through a wire without its disconnection. A possibility to measure current without (a short-time) disconnection of a circuit is naturally convenient for several reasons – measurement speed, safety point of view and last but not least – in many cases it is impossible or very complicated to switch off a measured circuit and to connect an ammeter into series. Times, when such a device was “only” an Ammeter are a long time away and modern clamp multimeters are literally universal devices, often able to replace common multimeters. A big majority of clamp multimeters is able to measure only an alternate current (AC). More sophisticated devices, to which also UT203 belongs, are able to measure even a direct current (by means of a Hall detector).
As clamp multimeters measure current on the base of magnetic field induced around a lead, it is only possible to measure current of wires, which are accessible separately – for example in distribution boxes, at terminals of devices and similar. In principle it´s also possible to measure current flowing through several wires at once, but it´s necessary to take in mind, that a measured value will respond to a vector summary of currents, thus it will depend on a mutual phase (at AC current) and or on the direction (at DC current) of current in wires.
UT203 represents a modern multimeter with an automatic range selection and a max display reading of 3999. Neither other measuring parameters are not impoverished – voltage can be measured in five or four ranges respectively (DC/AC) and resistance even in six ranges of 400Ohm to 40 MOhm. UT203 also offers measuring of frequency (in 7 ranges), duty cycle, diode test and continuity test (0-50 Ohm). Range selection is automatic with a possibility of a manual selection. Detailed information will provide you the UT203 user guide.
In case of interest, please contact us at firstname.lastname@example.org.
UT203 clamp multimeters „see“ even a DC current - [Link]
Kasbah posted his Nomech mini project, a 4×4 projected capactive touch board using Atmega32u4 and back-fire LEDs for each button:
It fits SoB 100x80mm but the top acrylic will sit right on top of the PCB as the dielectric properties of whatever is touching the electrodes matters a lot. If this works well then I might scale it up to 8×8. I want it to work as a cheap monome replacement without using mechanical buttons; hence the name “nomech”.
Nomech mini, a 4×4 capacitive touch button grid - [Link]
Jacob Beningo writes:
Signal generators are a handy thing to have around the lab. They are perfect for testing inputs on a new hardware design and verifying the behavior of a circuit before connecting all the pieces together. In recent years these lab tools have not only decreased in size but also in cost. The result has been a plethora of portable versions that now exist on the market.
For an engineer-on-the-go, this is very convenient but often times having to bring one more piece of equipment always seems to put the tool bag over the 50 pound limit. This is one reason why it is becoming popular to design lab equipment that can be plugged into a smart phone. Rather than carry around another device with a computer in it, utilizing the computing power and capabilities of the phone allows the device to be smaller, cheaper and weigh less!
Turn a smart phone into a signal generator - [Link]
RK-1 is a wifi enabled mobile robot that you control using your iOS or Android tablet or phone that makes your Arduino projects mobile.
The RK-1 is a fun mobile robot, that uses an ad hoc wifi connection, which is controlled using your iOS or Android device.
The control board on the robot is built on the Arduino hardware/software architecture, which is open source, and the controller software and hardware will also be available open source. The idea is to give the community the ability to make Arduino projects mobile. There is no end to what you can do- you can add sensors and actuators to this fun little device and control it remotely.
RK-1 – a wifi Arduino mobile robot for iOS & Android devices - [Link]
iFixit dives into their 5th Gen iPod Touch 16 GB teardown with the usual gusto–here are excerpts.
Teardown: 5th-gen Apple iPod Touch - [Link]
Here is the properties of the project:
- Cheap: The component total should be below $5
- Using TI’s MSP430 line of MCUs what I’m learning now
- Able to measure till 10MHz – Using LED display
- Able to calibrate
- achieve maximum +-10Hz error at 10MHz
Cheap frequency counter based on MSP430 - [Link]
SimpleAVR over at the 430h forum shows off his Educational BoosterPack 8 bit FFT Spectrum Analyzer project:
SimpleAVR comes up with unique Launchpad projects. These include his wire clock and spectrum analyzer projects. This time he wired the CircuitCo Educational BoosterPack to a Launchpad to sample audio and have the LCD display a spectrum.
Educational BoosterPack 8 bit FFT spectrum analyzer - [Link]
Bruce Trump writes:
Slewing behavior of op amps is often misunderstood. It’s a meaty topic so let’s sort it out.
The input circuitry of an op amp circuit generally has a very small voltage between the inputs—ideally zero, right? But a sudden change in the input signal temporarily drives the feedback loop out of balance creating a differential error voltage between the op amp inputs. This causes the output to race off to correct the error. The larger the error, the faster it goes… that is until the differential input voltage is large enough to drive the op amp into slewing.
Slew Rate – the op amp speed limit - [Link]
From now, you´ll find in our store the top-quality capacitors from company AVX.
A tantalum capacitor may be for many designers a component with a “smell of alchemy”. It´s not used as often as for example electrolytic capacitors, it´s more expensive and it doesn´t hesitate to fire off at improper handling. Despite these facts, it´s used in many devices and features several advantages, which predestinate it to many applications.
Among main advantages of tantalum capacitors belong small dimensions, temperature stability (C vs. t), very long lifetime (self-repair ability), relatively low serial resistance (ESR) and virtually no dependence of capacity on a DC voltage. Their usage is for these and other reasons beneficial in switch-mode power supplies, digital circuits (processors) in a measurement equipment etc.
Tantalum capacitors strictly require observing a maximum ripple current and also a maximum operating voltage. A low ESR can be a cause of extremely high inrush current after connecting to a hard power supply (for example a battery), which is able to damage a capacitor. From this reason, it´s advisable to design a circuit in a way, that this inrush current was limited, or not to use tantalum capacitors as the first – input capacitors. When these basic requirements are observed, tantalum capacitors will reward us with reliability and long-term stable parameters.
We´re glad to be able to offer you tantalum capacitors from company AVX, by which we replace capacitors of our previous supplier. AVX belongs to a top in this segment and its components meet highest criteria. Also positive is the fact that the price of these capacitors is comparable and in some cases even lower to those of previous types.
On stock we keep the universal TAJ series. Upon request, we´re able to provide you also other series, for example the TPS with a very low ESR. Detailed information will provide you the datasheet TAJ and many useful documents regarding max. operating voltage (derating) , max. ripple current and the leakage current.
Tantalum capacitors from the world-class producer on stock - [Link]