New answers tagged

0

If you are you using the U-Blox development board, you'll need to rotate this resistor (bright green highlight): This way: And connect the active antenna to the "RF_In" U.FL connector.


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You need a component--it will have your schematic symbol and your PCB footprint, and sometimes a 3D model. Sites like this offer some for free, and many manufacturers will provide component models. If not, you can create it yourself; it's basically the same as what you're doing now, but if you use the part again you'll already have it.


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The purpose of R2 is to absorb the bias current that comes though the base of the lower transistor. if you want to drive a LED from this gate connect it and its resistor to the output, instead of inserting it into the circuit.


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A real gate would not be able to supply anything like 455mA. You've loaded the output with far too low a resistance. Try something more like 100K or 10K. They've probably added a placeholder 10\$\Omega\$ resistance internally just to prevent infinite current if you short the output in the simulation. A real gate would be more like 100\$\Omega\$ (though it ...


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That circuit isn't very good. ... what is the usual voltage or current requirement for an A/B input to be considered in the 'on' position? It's whatever you define it to be based on what you consider acceptable as high and low on the output. simulate this circuit – Schematic created using CircuitLab Figure 1. The problem. The problem is that the ...


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What is the most common schematic to show a logic-and gate (without the symbol itself)? Figure 1. Function Block Diagram (FBD) is popular in some PLC programming languages, with Germans particularly fond of it. Image source: Science Direct. I have come across various schematics showing input nodes A and B (with nothing connected to it), but I'm not sure ...


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OrCAD itself doesn’t have such a ‘beautifier’ function. (My pet peeve: having to deal with schematics that use half-grid or off-grid lines.) Some things could probably could be fixed with a tcl script, but that’s more work than... just redrawing it. Why? I will redraw stuff if it’s that messy, has poor structure, or poor reusability. I will redo them to ...


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Sometimes it can be helpful to open the files in a hex viewer utility that shows the binary file contents in hexadecimal and ascii format side by side. Some software packages may embed a vendor specific header or text string that can can help to identify the source tool set.


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There is no such option in OrCAD Capture because "beauty" is very subjective. You could take a look if you could find an app that meets your need: http://www.orcadmarketplace.com/StoreHome.aspx Or guess what, you can make your own! With writing a TCL script, you can implement a menu option that can manipulate any type of objects (and therefore wires) and ...


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what does the line with an empty circle (the terminal symbol) really represent? My understanding is, it is simply used to represent the label the voltage at junction/node. Is this correct? They are just tapping points or nodes. I think them like an option to connect or insert a wire. it can be input (\$V_B\$) or output (\$V_C\$). It is just a ...


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Figure 3-4 is showing an oscillator instead of a crystal. The XO pin on the PHY is meant to provide an excitation source for a crystal located close to the IC. However, an oscillator contains this excitation source along with other circuitry to stabilize it and provide an output clock. Connect this output to both the PHY's XI pin and the MAC's REF_CLK pin. ...


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Libraries can be exported to and imported from xml. With this and some Java coding should get you what you want without knowing the format. You could also reverse engineer the hex format from the xml. For large jobs, it's probably worth purchasing CIS. OLBs are very difficult to deal with in Capture.


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You're having a lot of trouble being consistent with this project. Coloured circles seem to be components. Here you have a component with only one lead. Here you have a component with two leads but no identification and no indication of polarity. Here you have a node with four connections. The "proper" schematic shows a maximum of three at any node. You'll ...


1

Your reasoning is correct. The control of the LEDs should work as you describe. The Bus terminals that you describe are NOT actually bus terminals. Instead they are Logical Connections. They are used to indicate that a signal is carried to a different sheet / page / diagram within the schematic. In this form a 'box with a pointy end' (commonly called an ...


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The BJTs schema states that if you write a 1 in LED_R, you enable the BJT thus turning the LEDs on. Is this correct? Yes. The second part: The symbols are called off page connectors. Normally they are sued when you can not complete the drawing of that particular net in the same page. The shape of the symbol depends on whether t shape is near the ...


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Yes, your reasoning for the transistor circuit is correct. The input and output symbols are not universal. Sometimes they indicate signal direction, sometimes not. A good schematic (for westerners at least) should have inputs on the left side and outputs on the right side (western people think left to right). What is more universal is that connections ...


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Bringing this up again because it is still a problem and I had to find a work around. I am using Altium 19 and had the same issues. I found that the best solution was to use the Find and Replace Text option, which is CTRL-H, then specify "Designators" as the identifier. (https://www.altium.com/documentation/altium-designer/sch-dlg-findandreplacetextfind-and-...


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The open circle is an unlabeled terminal for the input voltage. The input should be at least the output rating (5V) plus (per the HT1050 data sheet) the 300mv dropout voltage. Call the input range 6v to 12v to be safe. The symbol (mis)labeled 9V is a polarized capacitor. Again, per the HT1050 data sheet, 10uf @16v should be fine. The ground symbol you ...


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It is for EMI purposes. Even though a single row is scanned every 4.5ms or so (about 220Hz) if the scope picture in the service manual is accurate (it may not be), there are 16 scan outputs (15 used), so the scanning happens at 3.5 MHz rate (my estimate, could be wrong, most likely it is slower given the RC time constant of 1 MHz and the pulse shape on ...


1

To make a distinction between the electrical type of leads/pins/pads/balls there could be on an electronic device, there are: Inputs: Signal input, usually small voltages/currents, analog or digital. Outputs: Signal output, ditto. Can be further refined as "push/pull" (driven high or low, never floating), or "open drain/collector" (floating or low) and "...


3

Technically: Leads (thru-hole and SMD packages that have metallic protrusions such as DIP, SOIC, SOT, and TQFP), Pads (SMD like QFN without metallic protrusions), Balls (BGA) Electrodes (tend to be for larger, higher voltage things, especially older equipment like vacuum tubes) are all distinct things. But no one cares. It's all used interchangeably. "...


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Leads, legs, pins, pads, and whatever the holes/sockets are called that BGA parts have.


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Figure 1. All grounded points are a single node.


1

It sounds like the real opamps you used in the circuit are going unstable. This could be due to a phase margin that is unacceptable. You basically have two series opamps and a MOSFET in a control loop and this can easily go unstable. A single opamp with local feedback can easily be made to go unstable (how you make an oscillator) so your configuration is ...


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As explained in an answer to your previous question you are being inconsistent with your nodes. You have shown three terminals on R1 in your network diagram. R1 can only have two. You need an extra node. Figure 1. Missing node.


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When you design a circuit in a given CAD tool, your design is reduced to a list of nets called a... Netlist. A netlist includes all the components and the nodes in your design. A node is a conductor to which your components connect. This makes sense when you think about the most basic representation of components and conductors. The Former being an input ...


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The nodal equations will be (N-1) for a circuit with N number of nodes. Hence, the N-1 will be the number of variables (currents). If you can find the number of nodes, you will be able to find number of currents you are requested to solve. To solve, there will be still challenges for example: when there are dependent sources


0

The voltage drop 2V for the LED is coarse approximation which assumes the current and that can give acceptable results in practical situations, but the small difference you noticed comes from more exact law between diode's current and voltage drop. That law is known as Shockley's equation. User jonk has shown how applying Shockley's equation generates a ...


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You can't force voltage drop. Suppose you have three identical things which drop 5V each. And you connect them across a 9V supply. What actually happens? They drop 3 volts each. Why? Because they have to. So what happened? Clearly you got that 5V voltage drop number from somewhere: a data sheet, or calculations. Both would have made certain ...


0

Again, I don't know the actual parameter values that your simulator is using. But it is probably using something like \$\eta=4\$ (the emission co-efficient.) You know about \$V_T=\frac{k\,T}{q}\$ as the thermal temperature voltage and again I'm going to assume a saturation current of \$100\:\text{pA}\$ for the LED and thereby move directly to a closed ...


0

I'll get right to the point here. I don't know the actual parameter values that your simulator is using. But it is probably using something like \$\eta=4\$ (the emission co-efficient.) You also already know about \$V_T=\frac{k\,T}{q}\$ as the thermal temperature voltage. I'm going to assume a saturation current of \$100\:\text{pA}\$ for the LED and thereby ...


0

You can solve this graphically, if you have a current vs. voltage curve for the LED. This is an actual measured curve for a red LED. I can't use your exact example because the voltage is outside of the curve. But, here is a similar analysis. If your voltage was 6V, and you had 3 of these LEDs in series, what would the current be? 6V / 3 LEDs = 2V per LED. ...


0

First of all, in your initial calculation, you assumed that the LED will drop 2V no matter what current is flowing through it. In practice its voltage will vary depending on the current. If you have a data sheet for the LED, it should specify the current vs. voltage for the LED over some reasonable range. In your simulated circuit, you put 3 LEDs in series ...


1

Are these two circuits identical? No. Figure 1. The net diagram is missing the node between R1, R2 and R3. This seems to be another episode on your strange electrical journey. As mentioned in an answer to your previous post I'm not sure that you'll be able to communicate this stuff with anyone else.


1

You need to pay attention to the wiring, the way you have drawn it in LTspice is wrong. Then again, the source picture is terrible, too. It's always a good thought to double check where you get your schematics from. You should also know this schematic is a very, very crude one that should not be used in practise.


2

In a refrigerator, the compressor is a mechanical device driven by an induction motor. This about how motor works (as opposed to how a compressor works. The characteristics of a compressor have some influence, but the essential answer is given by the characteristics of a motor independent from what it is driving. The motor draws a higher current when it is ...


2

Here is a greatly simplified schematic and simulation. The motor starts at time = 1 second. Half a second later when the motor has started up, the load drops. The house wiring resistance will cause the voltage to sag when a large load is applied. simulate this circuit – Schematic created using CircuitLab By $R_T$, I denote the total resistance ...


0

A compressor has a motor and the motor is attached to a load that has torque that has to be overcome to get it to rotate because of the piston compressing on each rotation. From this site: Once the motor starts rotating at a reasonable speed, the inertia of the parts helps overcome the torque as the piston compresses the refrigerant, but as it is ...


2

It is sufficient to know that a fridge has a motor. When it starts, it takes a huge surge of current until it has reached the target speed. Wires have resistance. So when there is current running in wires, there is a voltage drop due to resistance. So the voltage drops at the lamps too when the motor takes a surge of current, and that voltage drop is easily ...


4

I'd say the best part of all this is a comment by @DKNguyen: "but in the end, is it useful?" You can call those nodes any way you want... and in the end it will give you exactly zero useful information. Here is why: simulate this circuit – Schematic created using CircuitLab As you can see, I haven't changed anything at point B. It is still "3-way" ...


0

Not that I know of. And I think the RefDes being relatively ordered and close in number matters more on the layout than the schematic. On the schematic all components associated with that part of the circuit are already right there in front of me. On the PCB, if I am looking for C15, and I see C14, C17, or C18 first then I expect C15 to be nearby and not ...


0

On a schematic, I would generally label components left-to-right and top-to-bottom, while trying to keep parts in a logical block together. For example, in a multi-stage amplifier, stage 1 might have R1 - R5, and stage 2 has R6 - R10, even if that violates the left to right and top down rule. Often, once a PC board is designed, the components are re-...


0

There is no standard convention, or even a widely-used ad hoc approach. These labels are called reference designators. You must make sure that the first letter is correct for the type of component being labeled...that much is standardized. Do not reuse reference designations...if you delete R1 from the schematic you should never have another R1. You should ...


2

For what it is worth, I have used the textbook "Circuit Analysis and Design" by Ulaby, Maharbiz, and Furse. This book uses the following definitions: Node: An electrical connection between two or more elements. Ordinary node: An electrical connection node that connects to only two elements. Extraordinary node: An electrical connection node that ...


2

No, because a single node does not define whether something is in parallel or series, and even the terms parallel and series quickly lose meaning as you get more components. Look at your example B closely enough and you will see that your "definition" is downright fuzzy. Your components are unlabelled which makes talking about it unwieldly. Resistors from ...


40

DC Level 0 Diode The level-0 approximation of a diode is simply an assumed voltage drop across it when forward-based and infinite impedance when reverse-biased. When reverse-biased, no amount of reverse-biased applied voltage can break through the device --- it can stand off an infinite voltage. (For this level and the following levels below, I will not ...


1

You would also not use giant circles with +/- inside them. You would use commonly understood symbols. A tiny circle with a +/- beside it on the outside is fine. It makes it clear it is just a pin, and not a component unto itself. The large circles with +/- makes it look like it is its own component. For #2, you would normally put the + at very top instead ...


1

If you are determined to break up the battery then you should use one of the following ways. It is fine to try to rearrange a schematic in order to help you understand the circuit better but there is a point at which you go too far. For example when you have two terminal (+) and (-), then you place them like I demonstrate in my first schematic. I have never ...


2

Your circuit is open so no current can flow. You must connect the battery negative to the other end of the circuit. The convention is that we use the ground symbol to signify points that are connected on the common reference. This can be handy in a complex schematic as it avoids many wires, connections and cross-overs. simulate this circuit – ...


0

It's not immediately clear what you're trying to do with your hand-drawn schematic. Drawing the direction that you think current should go may help with that - Both in your understanding of the circuit, and our understanding in what you want out of the ECAD tool. With regard to your CAD schematic: Your voltage source in that configuration doesn't do ...


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