
High precision analog front end (signal conditioner) presented here can be used for portable ECG equipment that requires single-supply operation. There are two kind of amplifiers on the circuit diagram, the instrumentation amplifier INA326 and the dual precision amplifier OPA2335. Both operate from a single 5V supply and apply autozeroing techniques. Autozeroing techniques will keep [...]
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On the circuit diagram, R1 is used to senses current flow of a power supply. We could use JFET as a buffer because Id=Is, therefore the power supply current flow is accurately reflected by the output monitor.
Here’s the circuit diagram:
[Source: National Semiconductor Application Note]
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This is a simple circuit that can be used to convert a 4-20mA signal to a 0V to 5V analog voltage. It is ideal conversion to digital with an analog-to-digital converter (ADC). In this circuit, a current-sense amplifier (IC1) is used to monitor the loop current. To generate a ground-referenced output that ranges from 0V [...]
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The signal can be converted by piezoelectric films in many ways such as thermal to electrical (temperature sensor), mechanical to electrical (microphone), and electrical to mechanical ( a loudspeaker). The circuit is signal conditioning amplifier for piezofilm sensor which use three op amps and has a high-input-impedance differential charge. Here is the circuit :
This circuit [...]
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A modulated current is provided by the integrated rotational speed sensor KMI 15/x. This current signal must be converted to ground referenced voltage signal, matching the logic levels of the processing unit for digital signal processing. This signal conditioning can be done by using this circuit. This circuit consist of protective elements to suppress line [...]
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The digital meters is lack of accuracy and resolution in comparison to drawing information upon a measurement’s rate of change or tracking a reading’s trend. To solve this problem, we should use analog moving-coil meters. Here is the schematic diagram of analog moving-coil meters :
This circuit uses 8-inch moving coil meter with a measuring current [...]
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