The diagram that shows how the parts are hooked up logically. If your question is about a specific schematic software package, use that tag instead.

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1answer
47 views

Input and Output symbols in EAGLE (perhaps with Labels and XREF)

I'd like to create arrows in my schematic. The solution (using XREF) to an older, related post gets me most of the way there: Arrows on connections in schematics BUT, with that approach, the net ...
5
votes
3answers
434 views

Is it OK to inject voltage to an unpowered LDO output?

I'm designing for the first time a PCB that can be powered from an external +12V supply or from the USB connector. In the input of the board, just after the power connector (VINLDO net is the +12V ...
0
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0answers
68 views

LED Light Trains

G'day, I'm building a table at the moment and I've got old school PCB and components all over it and a 'Danger High Voltage Keep Out' sign in the centre. I had the bright idea of wiring up an 9V LED ...
0
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2answers
165 views

Resistor circuit problem

I am having trouble with a circuit: simulate this circuit – Schematic created using CircuitLab I must calculate the voltage across R1.My answer is to first compute the current running ...
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1answer
32 views

Where can I find schematics for the Microchip development kits?

I cannot find schematics on the page of development boards. Is it possible (generally) to get schematics of PIC development boards developed by Microchip?
0
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1answer
38 views

Fritzing doesn't treat breadboard power rails as conductors

I'm starting with Fritzing and created a simple schematic. All good. Now I want to turn in into a breadboard layout for my son to follow. All the components are there and connected with dotted lines. ...
0
votes
1answer
29 views

Is it possible to change the grid size in Quartus II schematic window?

Having a schematic for the top level structure of design appears to be a good idea. I have a few schematic symbols that I want to edit. The signal name is too long and does not appear correctly in the ...
0
votes
2answers
80 views

How do I change the frequency of this Vibrato-Circuit?

I am currently looking at an old 60's Transistor Organ (Phillips Philicorda GM752 to be exact). It has an integrated Vibrato-Unit, although the only modifyable parameter of it is the depth (amplitude) ...
0
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1answer
32 views

Altium de-highlighting nets after using 'Find Similar Objects…' command

I can't work out why Altium is doing this, or how to undo it, or how to make it stop doing it. It happens when I use the 'Find Similar Objects... ' option; all of objects that it hasn't found are ...
5
votes
1answer
309 views

What is this schematic symbol representing?

I found this symbol in some datasheet. But I have no idea what is it? Can anyone tell me?
1
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1answer
40 views

Making sense of Cadence schematic source files

I'm looking into writing an application to visualize existing cadence (OrCad) projects when provided with the projects design files. I've had a look through the project directories and it looks like ...
2
votes
0answers
45 views

Using a CFL ballast to power 9W UV tubes

I would like to build a low-cost home UV exposure box for PCB manufacturing. Recently my attention was brought to these dirt cheap UV bulbs which are used in manicure drying lamps. I have the ballast ...
1
vote
1answer
88 views

PNP or NPN Transistor for this schematic?

I am quite new to electronics and hoping to build a voltage regulator using the schematic below. I will be using a 7806 regulator and a 7.4 Lipo battery (yes, the schematic is probably a little ...
1
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1answer
63 views

Where to find Advanced Schottky TTL Schematics

I am currently having difficulty locating the circuit diagrams/schematics for the Advanced Schottky versions of the 7400 IC series. While the standard TTL data books seem to have depictions of the ...
4
votes
3answers
317 views

How to choose components for a circuit

I designed a simple circuit: that I would like to put components on - the point of the circuit is to light the LED when the voltage source is above 4 volts (it won't be more than 5), so I am ...
1
vote
1answer
36 views

How to avoid gated clock on a flip-flop?

I've read that it is a bad practice and I should use the enable signal. Is it also a bad idea to connect a gated, divided clock signal to the enable input?
1
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1answer
44 views

PCI 164-Pin Design on Altium

I would like to design a PCB having PCI 164-Pin on that shown at image. Is there any component I can add to schematic on Altium or should I just put some I/O ports on schematic?
0
votes
0answers
42 views

Using PNP 2N3906 to signal GPIO LOW when negative pulse is detected

http://www.savagecircuits.com/attachment.php?s=04cc498cb970ec62cdb517a60346c629&attachmentid=290&d=1430452949) In the attached schematic +5v input is turned into GPIO Low while 0v input is ...
1
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3answers
270 views

What does this symbol mean?

What does this schematics symbol mean? Taken from here. I got the PCB and it's not a button.
0
votes
1answer
39 views

problem on connecting devices in eagle

i'm still a biginner in using eagle .... well everything is almost fine but i keep having this error .... although i cheked a 100 time Only INPUT pins on net 25 Only INPUT pins on net RXCAN ...
0
votes
1answer
97 views

What happens to the output of Optocoupler input voltage is negative

Here is an example of circuit using VIshay Optocoupler 4N25 5V to 3.3V GPIO Output (Inverted) Logic +5V Input ---> 0.0V output GPIO LOW +0V Input ---> 3.3V output GPIO High What happens to ...
0
votes
1answer
68 views

What is this M01PTH I see referenced on schematics?

What is this part "M01PTH"? I'm interested in building this "BBQ Temp Controller" Arduino-based project here: http://hruska.us/tempmon/ One component involved is a 12v blower. In looking at the ...
0
votes
0answers
43 views

How do I create GPIO outputs from circuit to connect to Arduino Micro

how do i design the GPIO outputs so i can connect it to two pins on my Arduino and get the readings. ie. if green didoe is on GPIO 1 = High, other wise Low if red diode is on GPIO 2 = High, ...
0
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0answers
16 views

Unexpected error after Arduino Uo schematic upload to Eagle

I wanted to learn a little bit in board schematic analyze/modification. I am learning Eagle so I've downloaded Arduino Uno official files and the error appears: I've already done 2 or 3 basic boards ...
1
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1answer
32 views

Is it possible to edit gerber file using allegro?

I want make some corrections in gerber file. Is it possible using allegro? Or is any other better method to do it?
1
vote
1answer
111 views

What does the series of circles in a schematic mean?

I saw this series of 4 circles in the schematic of an Arduino board. Similar circles appear in other Arduino schematics, though I don't think they are Arduino specific (which is why I post here ...
0
votes
2answers
123 views

Dual rail switching PSU critique

I am looking for feed back on the following power supply design. This power supply is intended to have 2 outputs: 24V @ 500mA and 32V @ 850mA. When the power supply is in standby, J1 pin 1 is @ 0V, ...
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votes
2answers
109 views

How to view SchDoc files online?

I have a file witch was designed with "Altium Designer". How could i view this file without needing to install "Altium Designer"? it is preferred to do this with an online app.
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2answers
196 views

Schematics: Effect factor and impedance

I have a questions regarding a simple schematic. I would like to calculate the total angle (φ) and power factor (cos φ) of this circuit and the total impedance (Z). -- Not using the complex-method ...
3
votes
2answers
232 views

The usage of chip topography and diagram(schematic)?

Are you an EE? Do you use TI Op-Amps? then you should know the answer of this question. probably that could be interesting for us. If you take a look at the datasheet of TI(or a few other companies) ...
0
votes
4answers
109 views

Optimize PNP/Diode Schematic

I am trying to design a circuit which has four switches, numbered 1-4 as in the diagram. The circuit should function such that closing switch n turns on light ...
5
votes
2answers
520 views

What does it mean when components in schematics do not connect?

I'm fairly new to the whole Arduino world, and I'm just really curious about this schematic that I came across... I can read the basics of a schematic, but this one has me puzzled. What are the ...
0
votes
2answers
116 views

How should I connect / design this tactile push button on PCB & schematic?

I have need for a tactile push button that I am using to cause an interrupt on a microcontroller. I have found my desired switch (linked above) but I am having trouble deciding the best way to design ...
0
votes
0answers
34 views

New guy on the block…first project

So I am building boom box out of an ammo can. I want the ability to be able to use external power or battery power, with the option of using a switch to go from one or the other. When on external ...
2
votes
1answer
174 views

How can I reset all part names in Eagle PCB?

I've built a large PCB, which merges about 17 schematics. There are about 1000 components on the board. What I need to do now is rename all of the resistors and capacitors. Currently the parts are ...
3
votes
1answer
135 views

Unable to identify the symbol in schematic

In my job I came across reading a customer schematic. I am facing trouble in identifying the marked part of the schematic, which is connected at the pins of uUSB ...
3
votes
2answers
317 views

Finding the schematic of a black box with unknown impedances

I'm struggling with trying to understand a piece of homework in Electrical Engineering that I'm really trying to solve on my own but now I'm basically stuck. The assignment is to find the schematic ...
4
votes
1answer
133 views

Help understanding circuit in Forrest Mims' Getting Started in Electronics

I've worked through Forrest Mims' Getting Started in Electronics, but cannot figure out why the below circuit (on page 92 in the fourth edition) claims that LED1 and LED2 alternate in being lit ...
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0answers
93 views

What is the IEC 60617 schematic symbol for jumper and test point?

What is the IEC 60617 schematic symbol for jumper and test point? I have tried to find it in the official standards but it seems not to be defined explicitly.
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votes
1answer
49 views

Identify this 2xNPN AC-coupled preamplifier circuit

My workmate has this nifty little EMI-detecting wand he built back in 2000. It senses EMI fields using an approx. 200 turn air-core coil, and converts them to audio signal. He uses it to detect e.g. ...
2
votes
1answer
69 views

Inductors with no value on schematic

I'm reviewing a schematic so that I can replicate it and I've come across several labeled inductors with no values. From my Googling, It seems that these may actually be ferrite beads. My question is, ...
0
votes
2answers
125 views

Bench power supply “Issues that rouse during build”

I'm building a power supply, based on this instructable and this one I am using 24volts DC power supply, 7+ amps circuit is based on LM338 / 7805 / 7812 Circuit is working although few things ...
0
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0answers
98 views

Schematic design critique

I designed a schematic for my project and I'd be thankful if you could give me any feedback on it. I'm specially looking for anything wrong or inefficient with my circuit. The purpose of this ...
0
votes
1answer
290 views

Power on reset circuit for microcontrollers

In this schematic, there is a reset circuit with two pushbuttons: The button marked "warm reset" sends an active low signal to one microcontroller, while the button marked "cold reset" sends a ...
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votes
1answer
117 views

Orcad DRC Error

I am new to Orcad Cadence 16.5 Schematics. i drawn a schematics and while running DRC, the following error repeatedly occurs for all Components. Please help me to eradicate the below errors: ...
0
votes
1answer
73 views

Learning Schematics

I'm trying to learn to read apple schematics and I have a few question regarding components and lines. I have circled areas of the image below and numbered them according to the question I'll ask. In ...
1
vote
1answer
66 views

Unshown compile error in Altium Designer 13.1

I have a schematic sheet in Altium Designer 13.1 and I made an unconnected label on purpose. (In the red rectangle) My problem is: when I compile this sheet, there is no error shown in the ...
0
votes
1answer
77 views

Schematic shows some resistor values as DNE

What does it mean on a schematic when some resistor values are listed as DNE?
2
votes
1answer
122 views

LM2907 schematic critique

I have been working with the LM2907 as I have been designing a few circuits around it. This has lead to me wanting to understand more of its inner workings and build up a breadboard model of the ...
0
votes
1answer
96 views

What does this symbol represent?

I am trying to understand the internal circuit schematic of the LM565 phase locked loop IC, on page 6 of this datasheet: PDF Datasheet for LM565 from TI website In the upper middle, there is a ...