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current measurement
Ok, I've got a 0.1ohm 4-terminal sense resistor.
The minimum current I want to measure is 100uA.
I now want to amplify the voltage with a non-inverting amplifier with gain of about 20.
That gives me minimum 200uA, and with the 16bit ADC and 2.5V reference, I can measure...
What is the best way to measure current. It must be very accurate. Current can go as high as 1A.
It is basically current going into ground, so at the moment I am thinking of a precision 50 milli-ohm resistor just before ground with a 16bit ADC just before the resistor. The ADC has programmable...
The cap will act like a voltage source with its positive terminal at A.
The current actualy flows from C to A, but for all practical calculations we say it flows from A to C. The same is true for the battery, the current actually flows from + to -, but we say it flow from - to +(called...
Don't know how much you know about electronics. If you know a lot then my answer is stupid, but anyway:
Digital comms make use binary data(1 or 0), where there is two voltage levels and the highest voltage represents a 1 and the lowest represents a 0. Different protocols represent different...
Ok, with the resistors to ground, they would take care of the quiescent current and now I can get current in the range of 100uA's through my MOSFET.
I think the bleeding resistor should be small, so that it can take all the quiescent current if the output voltage of the LM317 is low.
The power...
The problem is that the current will go as low as 100uA, and possibly lower. I'm plotting the current vs. Vds of the MOSFET. Voltage source connected to the drain.
I just saw that the LM317 has a quiescent current of about 1.3mA, so I don't think my design will work with the LM317.
Re: PIC microcontroller
AVR is produced by Atmel. You get different models of a company's uController.
It is possible for example to get a PIC and an AVR that has the same functions.
With functions, I mean for example the same amount of memory, communication methods etc.
I have used PIC...
Was thinking about the LM317, but I'm not sure if that voltage will work. I need the voltage to vary from the threshold voltage of any MOSFET to 5V. A general MOSFET's Vtn is about 1.7V, but I'm still trying to find out if some of them are lower than 1.25V.
What if I put two diodes in series...
Thanks for the circuit. Was looking for current sources on google. Never thought about a powersupply. I'm using a 12V battery, so I'll just have to adjust a bit.
variable voltage source
Hi
I need to build a variable voltage source that can deliver up to 1A current.
The voltage should be able to vary between 0V and 5V and it will be driven with a DAC.
The DAC can output up to 5V, but can't give a lot of current, so it will be connected to an OP-AMP...
capacitor between power and ground
What is your application/circuit?
If it's on a long power line, it could be to just make sure that all AC signals are bypassed.
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