Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [current-sensing]

153 questions
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Current sensing nA to mA

I need to sense the current of a target MCU through various periods of its on/sleep/off state and then need to send this data back to another interface MCU to read out the value. They will be both on the same board, powered by 5 V USB. However these…
Andrea Corrado
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How is this a current mirror?

This article is talking about floating an IC's GND to use it at a common mode voltage higher than it is rated for. It then says it level shifts the IC's current output to ground by using the Q1-Q2 current mirror. I thought current mirrors BJT bases…
TotesMyGoats
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Can a floating capacitor terminal be used to collect electrons?

I want to collect charge from an electron beam source. For that, I'm proposing to put a floating capacitor with its bottom terminal floating and directly exposed to the electron beam gun. The top terminal would be connected to a transconductance…
Jorge Johanny Sáenz Noval
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8 answers

What is negative current?

I understand that voltage is relative to ground, so that can be negative. However, I'm currently looking at current-sensors (ACS712 current sensor) and in the performance characteristics table, it specifies the Optimized Accuracy Range. In the case…
Florian Humblot
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Wide range current sensing at +5kVDC

I am working on a control and interface board for high voltage supplies, which requires some current measurement to be implemented. The general terms of the question are similar to this one. The device through which I want to sense the current is at…
Magic_Matt_Man
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Measuring average current consumption in hardware

I'm working on a very low power budget, battery powered project. This project is allowed to draw 15uA (average) at 3v. The microcontroller we're using draws 4-10mA when active, and 2-3uA when asleep. The micro spends the vast majority of its time…
CHendrix
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The benefit to make or use a surface mount 4-terminal current sensing resistor

I find some precision SMD resistors are 4-terminal, like vishay's CSM3637P. It's constructed as below: It seems it only make a slot on each pad, then get two extra pad to do the voltage measurement. If using a normal two terminals chip resistor, I…
diverger
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Charge indicator with comparator - very sensitive to noise

I need an indicator when the current from my charger is larger than 100mA. I tried the below circuit but this seems very sensitivity to noise. Probably I am getting some ripple in the mV range from the charger. Is there a more robust, less sensitive…
Reto
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Noise problems in current sensing

I have the following circuit: simulate this circuit – Schematic created using CircuitLab I am using a motor from an electric bike, as a generator and I am rotating it using a drill, to test its regenerative properties. The energy generated is…
NickG
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Op amp with transistor in feedback

I am currently looking for a high side current sense IC. I have noticed that most of them that are without galvanic separation, are using an op amp with bjt transistor like in bellow schematics: The datasheet of TSC101 describes more or less how to…
Łukasz Przeniosło
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Current detector transformer on optocoupler

I need a current detector that outputs a logic signal (1 or 0). I DON'T need to measure current. Detected current: AC. Voltage: 220V. Load power: ~1kW. FOR EXAMPLE: I need a current detector that will give out + 5V at a current greater than 0.15A,…
Mia
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Detecting switch closure

Any techniques/circuits/sensors that can determine the open/closed state of a set of contacts, independently of whatever power or signals are being switched by the contacts? Obviously easy if there's no or a known load; but (for example): three NO…
tariksbl
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ESP32 using acs712 give wrong values

I'm trying to measure current with acs712 30A current sensor connecting to NodeMCU-32S but I'm getting wrong and unstable values. For zero current the ADC pin should read value of 2048 (esp has 12 bit sensitivity) but instead I'm getting values…
Electrician
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High side current sensing for negative high voltage

I need to monitor the current for a negative high voltage supply. I implemented the following circuit in a simulation program: https://www.maximintegrated.com/en/app-notes/index.mvp/id/1867 But this only works when the high voltage is +1kV DC. …
Chris Sy
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Automatic ranging current sensing

I am trying to implement a current shunt sensing circuit. This should be automatic and currently i want it to measure uA to around 200mA, and Change to the mA range at around 200uA. This is to profile sleep and active profiles in micro controllers.…
Andrea Corrado
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