Tagged Questions
3
votes
1answer
94 views
How to build a voltage-controlled current sink / voltage-controlled resistor
I am trying to control a current through several current-mirror device (specifically the IREF pin on the TLC5940) using a single potentiometer. I've tried using a ...
-4
votes
1answer
110 views
How to find the current and Resistance?
Ok Everyone DownVoted! i am sorry about the diagram! So i Updated it
this is my new diagram:
simulate this circuit – Schematic created using CircuitLab
Then Now how to find I1? what is ...
2
votes
2answers
103 views
Can a too powerful battery damage a circuit? [duplicate]
I have an IOIO board, a 13V 10A Battery (when I tested with my multimeter). For the IOIO board, 5-15V, ~10mA is enough. Can a 13V 10A Battery do wrong to the board or is it okay?
1
vote
1answer
155 views
How does current split in a circuit?
I'm redesigning a board that has a lot of peripherals attached to a SOC. These all use different voltages. Board is powered with 12V,1A
Most peripherals are connected like this:
RJ45 <-> GigE phy ...
0
votes
1answer
169 views
Need help designing a current controlled source in PSpice?
The image below shows an electrical network with 8 elements, a current controlled source, a bunch of resistors, one current source and a voltage source.
Although I haven't labeled them, there are 5 ...
0
votes
2answers
357 views
What is meant by relative voltage?
Suppose you have a circuit
,you are told that the voltage at point 2 relative to point 1 is -90V, the voltage across R2 is -30V and V0 is 200V.
What is the meaning of voltage at 2 relative to 1? ...
4
votes
2answers
190 views
Why don't my coil work?
I disassembled my old Niko RC car today. Thought I could play around with the parts.
But what I can't seem to understand is the coil. The powersource of the rc car is a 7.2v NiCd 620mAh battery. And ...
-3
votes
1answer
293 views
What's the cheapest, quickest way to obtain an adjustable constant current source? [closed]
I need a simple adjustable constant current source that provides 0.1mA-5mA constant current from a 9V battery. Ideally it would show the output current on an analog or digital readout, but that's not ...
30
votes
7answers
19k views
How to get more than 100mA from a USB port
I heard that the current limit for a USB port is 100mA. However, I also heard that some devices can get up to 1.8A from a port. How do you get past the 100mA limit?
