Converting 5V 7805 Linear Voltage Regulator to Produce 6.4V Output

Making a linear voltage regulator using 78XX integrated circuit series is very easy, it needs only one or two additional components to make the integrated circuit chip works. The problem arises when we need a custom voltage specs for the output, since they come in discrete fixed voltage variation (specified by XX parameter printed in the body of the IC […]

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Step-Up DC-DC Converter Circuit for Laptop Charger/Adapter, Convert 12V(9-14) to 19V(16-21V)

Step-Up Converter 12 to 19V for Laptop This DC-to-DC converter circuit enables automotive lead-acid battery to power your laptops/notebooks, converting 12VDC to 19VDC with good efficiency since it uses switching technology. I designed this circuit to make power backup for small home office  to provide eight hours backup for three notebooks.  The input voltage range is 9V to 15V, which […]

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Ressettable Electronic Fuse (Circuit Breaker) Circuit for Securing General Power Supply

Electronic Fuse Fuse or circuit breaker is useful to protect electronic circuit, especially the power supply. A short circuit or overload might damage the power supply if the connection between the power supply and the load  is not immediately disconnected. When we use conventional fuse, we must replace the blown fuse with the new one after fixing the failure which […]

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Electronic Relay Circuit Breaker Protects Boost Converter from Short Circuit and Overload

Boost Converter and Its Unprotected Nature Boost converter topology, where an inductor is alternately shorted to ground by a switching transistor in some portion of the cycle and connected in series with the load in other portion of the cycle, is inherently unprotected from load failures such as short circuit and overload (look at the figure 1 of  the reference […]

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High Side Current Sensing Using Transistor for Current Limiting Control

High Side Current Sensing Circuit Diagram

Introduction to Current Sensing Current sensing is sometimes needed in a circuit to measure the amount of electric current flow. In signal communication for example, current sensing circuit is needed to read the measurement of remote sensor via current loop.  Other common application is in the power supply circuit, when we need to limit the maximum current drawn by the […]

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Digital Control for Laboratory Power Supply Using Arduino

Figure 1. Arduino Duemilanove Board for Power Supply’s Digital Control Digital System for Display and Control As the second part of the first article Adjustable 1-30V Laboratory Power Supply, the digital control and display for our power supply will be presented here. The microcontroller used in the circuit is ATMEGA 328, a member of Atmel’s AVR microcontroller family. We use […]

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Adjustable 1-30V Laboratory Power Supply Uses Switching and Digital Control Technology

Figure 1. Assembled Hamuro Programmable 1-30V Laboratory Power Supply Laboratory Power Supply Requirement Power supply for electronic circuit experiments need some special features. Ideally we need a precise, stable, reliable, and easy voltage adjustment power supply for working convenience. Being precise means that our power supply should give a voltage as close as possible to the desired value. A stable […]

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Variable Dummy Load for Power Supply Testing

Figure 1. Assembled Variable Dummy Load To test real capacity of a power supply, we need a load with variable current consumption. If we have high power variable resistor such as tapped wire-wound resistor, we can directly connect this resistor and make some measurement. Unfortunately, this kind of high power resistor is expensive and not so flexible getting wide adjustment […]

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