by Peter Demchenko @ edn.com:
Low-current switching regulator ICs often use a Darlington as the output switch. The power conversion efficiency in this case can be improved with the help of only two cheap components. To make this possible, the chip should have a separate pin for the collector of the driver transistor Q1 (Figure 1). At startup, D1 forms a path for the collector current of Q1. Later, D1 and C1 comprise a current-additive rectifier which enhances the collector voltage and current of Q1, hence reducing voltage drop on the closed switch Q2.
Improve efficiency of low-cost switcher - [Link]
Energy is transmitted in different ways and one of these ways is electricity. It can appear in many forms and through various phenomena such as lightening or electromagnetic induction, and can be used in transport, electrical appliances, and in the residential and industrial sector, to name but a few examples. Physical magnitudes are derived from electricity such as the electric field, current, and electric potential. The latter two are measured in amps and volts respectively.
In order to measure the previous magnitudes and many others, ingenious devices have been developed, called multimeters, which are the perfect example of the high integrity and versatility of the most modern measuring instruments. They are powerful devices, small in size, but large in their ability to detect and solve electrical failures, measure a large variety of parameters such as current, voltage, capacity, resistance, and they are also equipped with additional functions which allow them to measure temperature, continuity, frequency, carry out diode tests or perform as an oscilloscope. Many multimeters have a USB port and have wireless transfer capacity (Bluetooth), which means that the measurement results can be sent to a PC or computer for later analysis. In addition, many of them are designed in such a way that their screen is removable, so that they can operate in difficult to access areas. Read the rest of this entry »
by Henrik’s Blog @ hforsten.com:
In my previous post I wrote about a circuit that would change it’s output depending on what was the spice simulations DC sweep range. Today I investigated the circuit a little and I was able to remove lots of components that didn’t affect the bug and this is the resulting circuit.
Metastable transistor circuit - [Link]
An application note from Texas Instruments, A single-supply Op-Amp circuit collection (PDF!):
There have been many excellent collections of op-amp circuits in the past, but all of them focus exclusively on split-supply circuits. Many times, the designer who has to operate a circuit from a single supply does not know how to do the conversion.
Single-supply operation requires a little more care than split-supply circuits. The designer should read and understand this introductory material.
A single-supply Op-Amp circuit collection - [Link]
By Dean Segovis @ makezine.com:
A transistor is an electrical component that functions, most basically, as a switch — in principle not so different from a light switch. Instead of a physical movement, however, a transistor is controlled by a flow of electricity. And unlike your basic light switch, a transistor can be on, off, or somewhere in between.
Non-Contact Voltage Detector - [Link]
by Deivaraja Ramasamy @ www.edn.com:
This Design Idea is able to turn off inductive loads at a very fast rate. When connected to a load (here 15mH + 10Ω), the modified freewheeling path in the clamping circuit based around M2 reduces the turn off time to 450µs. A simple freewheeling diode in place of the clamping circuit takes about 4ms to turn off the load.
Low-side switch with fast turn-off for inductive loads - [Link]
Dhananjay Gadre & Nidhi Sharma writes:
Microcontrollers, the heart of all modern electronic gadgets, are increasingly powered with sub-5V power supplies. This complicates the control of external loads powered by higher voltages. The reduced I/O supply voltage leads to increased complexity in handling high-side voltage switching. Figure 1 illustrates the conventional solution for controlling a 5V high-side switch, driven here by a 3.3V signal.
Zener level-shifter drives high-side switch - [Link]
This tutorial presents the basics of the varactor diode, or varicap diode, and describes how it functions as a voltage controlled capacitor. A test fixture is shown and used to measure the capacitance vs. reverse voltage. Finally, a voltage-controlled oscillator circuit is built and measured, showing how the voltage on the varactor diode is used to tune the frequency of the VCO.
Basics of Varactor Diodes | Voltage Controlled Oscillator VCO Example - [Link]
w2aew @ youtube.com writes:
A tutorial on the basics of an inverting and non-inverting summing amplifier using an op amp. The video assumes a basic knowledge of how inverting and non-inverting amplifiers using op amps work. If you are unfamiliar with this, I’d recommend viewing my video on how to easily understand the operation of most opamp circuits: https://www.youtube.com/watch?v=K03Rom3Cs28
Basics of an Op Amp Summing Amplifier - [Link]