I have a schematic that has the intersected circles that IMOD and IBIAS arrows point to and I wonder about its meaning     edit :   if I know that this symbol is a current sink ..how can the Control IC change the current passing through the LD ? and how can I relate the resistor connected to IMODN to current in LD ?
54780
In the datasheet for a A3503 Hall Effect Sensor, I saw a circuit diagram labeled 'Functional Block Diagram', and it shows a symbol I have not seen before. It's shown here between 3 - Output and 2 - Ground.  What is this supposed to represent?    The full datasheet is available
75511
In context to the diagram below , it is quite easy to find the current flowing through section AD , which turns out to be 2A , however , I cannot determine the current in any other branches with Kirchoff's Voltage Law . The branches AB,CD,DE and FA have no resistance across them so whenever I take those branches in any of the the possible loops , the potential drop/rise will always be 0 so the terms involving 'I' never appear and consequently they are indeterminable.So how do I find the magnitude of 'I' ? In this particular case I can guess than I=1A with junction rule and the symmetry of the circuit - the batteries have same emf, so what if the emfs aren't same ? then the original problem comes up again.
81021
I have some experience with highfrequency circuit analysys. However I am a newbie in PCB design. I am analysing this circuit:  (starts on page 36) and regularly see things like "OMIT" for headerpins or components like resistors or so.  e.g.:   p41 (6/6): the boxheader(?) on the left. P40 (5/6): R48 on the dev board are two small surfaces with some soldering on it but no component apparently. I can hardly see myself (de)soldering resistors on my new dev board...   Why is this being mentionned? What do the people who made the PCB mean by this?  I mean if this part has to be omitted, why did they even place it on the PCB?  Thx
64932
I'd like to include an oscilloscope symbol in my circuitikz diagram, like this:    I looked around, and it doesn't seem like there is one built in. Is it possible to get something like this into circuitikz?
68213
I don't really understand how these diodes in this circuit and similar circuits (like driving a relay circuit) protects the controller circuit from the energy stored by the inductance of the coil. I really appreciate if someone could graphically explain it. ( I mean how the the diodes block the current and etc)  the second question about this circuit is the capacitor. what happens if it isn't there?
76211
What's the purpose of the two capacitors in parallel on each side of the regulator in      I've seen similar setups in other similar circuits and can guess that it's related to one being polarized an one not, but I don't really understand what's going on there.
97109
Can anyone help me identify this component? It just says 0 or D on it (I think it's a zero). I tested it for conductivity with a multimeter - doesn't seem to have any (tried both polarities in case it's a diode). Tested for resistance: nothing (i.e. infinite resistance), although I'm not 100% sure I was touching the contact points correctly, so don't take this as an ultimate measurement. Thanks in advance!
91045
My lecturer has used some notation that I've never seen before: it is a (matrix) product symbol with a left-to-right arrow over the top. Does anybody know what this means?  Thanks in advance.  Edit: It looks like this:
74359
First off I know the switch the works I plugged it into a different circuit where I have another one and the pilot light turned on when the switch was on. However when I have it installed in the problem circuit the indicator light is switched and is illuminated when the light is off instead of it being illuminated when the light is on.  The circuit is for the downstairs lights in an older building so I am thinking it has to be something with how the lights are wired. The switch works the lights just fine so I am figuring it is something to do with the neutral side. I am unfamiliar with this light switch and how it works internally.   What would make the light come on one way in one circuit and opposite in another? I am unsure the exact brand I am an amateur electrician just helping a friend, but it is similar to the Leviton 15 Amp Combination Switch with 25-Watt Neon Pilot Light found on the home depot website. any help or ideas would be greatly appreciated
63953
What is the point of R2 in the following diagram:   I get that R1 controls the current to the Base, but what does R2 do?
56773
Could someone please tell me what the symbol ringed in red represents?     I know it has ON Switch pointing to it, but the symbol has other lables in different parts of the document.
26320
Shouldn't the current passing through a resistor be lesser than that which passes through a circuit? My understanding is that since Current = Charges/Time. If there exists a resistance to the flow of charges, then that must mean the charges slow down, meaning that more time is required to pass through a point. So, the current should then decrease. But, since this opposition to the flow of charges doesn't exist in the ENTIRE circuit, it should really only decrease the current in the resistor, right? Am I confusing the resistance of the resistor with the resistance of the wire? Any help will be appreciated! Thanks a bunch for lending me some of your time :D
117146
I would like to know how to understand/analyse the circuit below. And sorry but my level in electronics is not that high and I could only tell that the opposing transistors on the left are meant to cancel any current from the input , yet I don't really understand the B stage which I think the C stage is well related to , and if I wanted to analyse the nodes around the circuit apart from (A,B,C) How can I do it ?  Is it by measuring the current on resistors/nodes?  and note that the output voltage of the circuit in node C is zero this is what it meant to be.I would appreciate any help.  Regards
674
It is used on a small board RFID antenna circuit based on the TMS3705:    At the first check it seems to be a 0 ohm resistor, but the dimension 4x4mm its strange.  Any ideas?  L.
79339
I know how to detect when resistors are arranged in parallel or series arrangement and I can also find their equivalent resistance in simple circuits or when resistances are connected in form of triangle but what happens when the arrangement is complex like this :   Which resistors are parallel and which are in series ? How can I find the equivalent resistance in such cases ? Is there rule or method for figuring this out ?
103305
How can I typeset the following symbol for direct current (i.e. a = symbol where the lower line is dashed)?     The image above is an enlarged version, the size I need is like =, \approx, \simeq etc.
57558
I'm having trouble understanding something in one of my text books:     Let’s have a look at the implications of each circuit configuration.   Figure 3.13 shows the Conventional representation of a parallel   circuit. If you assume that the resistance of the wires can be   neglected, then the voltage drop across each bulb is equal to the   e.m.f. of the source, the dynamo. The Current flowing from the source   is divided between each bulb depending on its resistance (remember I =   E/R), Removing one of the bulbs would not affect the voltage drop   across the other bulb and would therefore not affect the Current in   it, although the overall Current from the dynamo would drop as the   demand has been reduced.   Specifically, the line about removing one of the bulbs not affecting the voltage drop. My understanding is that the sum of voltage drops in a circuit must be equal to the output of the emf, but the way I'm reading the text suggests that if you have three bulbs in a parallel circuit and you remove one of them, the voltage drop remains the same - this is what I don't understand, though. If you a lamp is removed, then that's one less lamp consuming emf. Does it not get redistributed to the other two lamps?  Likewise, the text mentions the overall current from the dynamo dropping because demand has been reduced.  My initial understanding was that current from an emf is only affected by the emf - not the demands of components further along the circuit, as in this case. What have I misunderstood?