A simple way of measuring the amplitude and phase difference between two high-frequency signals is provided by the AD8302 from Analog Devices (www.analog.com). The two input signals A and B are terminated with 50 Ω and fed to the internal logarithmic demodulators. Taking the difference of the outputs leads to a voltage which represents the[…]
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Transistor Tester Schematic Circuit Diagram
This tester is intended to quickly check whether a transistor is functional or not and possibly also select two or more transistors with (approximately) equal gains. This is about the simplest conceivable test circuit, so don’t expect super accuracy. The circuit has been designed only to quickly carry out a brief check when there is[…]
Read moreTemperature Sensor with Single-wire Digital Interface Schematic Circuit Diagram
A temperature measurement system with up to eight distributed temperature sensors can be realized using only a single signaling lead. This objective is supported by the Maxim MAX6575 temperature sensor (www.maxim-ic.com), which can be used to measure temperatures between –40 °C and +125 °C. It is housed in a small SMD transistor package (SOT23). As[…]
Read moreLM 3822/24 Current Meter Schematic Circuit Diagram
ICs for measuring currents usually employ external sense resistors with values of a few tens of milliohms. Not only are such resistors difficult to obtain, the circuit board layout can have a disturbing effect on the accuracy of the measurement. This problem is eliminated by the LM3822 and LM3824 ICs from National Semiconductor (www.national.com), which[…]
Read moreAmmeter Schematic Circuit Diagram
From the feedback from our readers, we have learned that the measurement of currents in the positive lead of a power supply is often fraught with practical difficulties. The circuit shown here will in many cases be a welcome aid. The design is not really new, but it is very useful. The required shunt[…]
Read moreStep-up Switching Regulator with Integrated Current Limit Schematic Circuit Diagram
In the form of the LT1618, Linear Technology (www.lineartech.com) has made available a step-up switching regulator with a current limit mechanism. This makes it easy to protect an otherwise not short-circuit-proof switching regulator with a current limit mechanism. This makes it easy to protect an otherwise not short-circuit-proof switching regulator: the input voltage is always[…]
Read moreLow-Cost Temperature Measurement with a Microcontroller Schematic Circuit Diagram
It frequently happens that you have an application in which you want to measure the temperature of a circuit or the outside world. This can be easily achieved using additional components in the form of ICs, or by using an RC network and a software routine. However, if all the I/O port pins are already[…]
Read moreSingle-Chip Switch Debouncer Schematic Circuit Diagram
Contact bounce is an age-old problem with all types of pushbutton switches and keypads that are connected to digital components. The measures that are used to deal with the repeated closing of the contacts when the switch is first activated include RC networks, flip-flop circuits, and software routines. Now there is a single IC that[…]
Read moreMeasuring Inductors Schematic Circuit Diagram
Often you find yourself in the position of needing to wind your own coil for a project, or maybe you come across an unmarked coil in the junk box. How can you best find out its inductance? An oscilloscope is all you need. Construct a resonant circuit using the coil and a capacitor and connect[…]
Read moreHow calculator works, Schematic Circuit Diagram
Before start making an adding calculator you need to have some basic knowledge of binary adder how to add the binary digit. As we know we use decimal number system in our daily life because of we have 10 fingers, and 10 fingers make us easy to calculate numbers, but not easy if the number[…]
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