Questions tagged [schematics]
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.
947
questions
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44 views
How to know if my custom made arduino schematic is working? [on hold]
I made my own Arduino schematic based on Arduino Due's schematic and added an MPU6050 to the board.
--Also I'm not certain that every component I'm using is necessary to my board (fig1), do you have ...
1
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0answers
136 views
Please check my board design before I waste money
TL;DR: Please make sure my schematic and board design won't blow up on me. GitHub Repo if you're feeling extra thorough.
Project overview
I am trying to create an Arduino based Bluetooth RGB led ...
2
votes
2answers
426 views
What is the meaning of “do not populate test points” in a board schematic
I was finding test points in a schematic of an Analog Devices Evaluation board. In one of the schematic pages, there is a clause mentioned "do not populate test points".
Does anyone knows what it ...
0
votes
1answer
48 views
What are the additional transistors used for in this hex inverter?
I'm learning about electronics and was studying the SN7404 hex inverter schematic when I saw this:
I naively expected just a single transistor (the one in the bottom right) and the input at the base ...
1
vote
1answer
37 views
Baxandall tone circuit passes signal through but does not alter its tone
I added an Baxandall active tone circuit to an existing overdrive circuit and I'm having an issue. The signal passes through the circuit/opamp and out to my volume control but the bass and treble ...
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0answers
31 views
Pin confirmation on pic for sd card connector?
I've had a first version of a connection to a sd card connector (DM3CS-SF) for my PIC32MX470F512L that did the following connections:
After trying to run an harmony example, using this config, the sd ...
0
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1answer
76 views
What could be the reason these wires need to be connected outside of the sensor?
Below diagram shows the inner system of a wind-meter and four output wires to power it and collect the 4-20mA output signal as current or voltage by using a resistor.
I verified with a voltmeter's ...
1
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1answer
70 views
Problem with boost converter
I am currently trying to use the LMR61428 boost converter IC with the configuration in the attached schematic and having an heating problem with the inductor. The inductor gets very hot very fast even ...
1
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1answer
84 views
What is this dumbbell looking symbol on this schematic? (looks like jumper pad, but with a short)
Regarding to SJ1 and SJ2 in this schematic:
On the board it looks like two ordinary copper pads but with a thin connection between them. Is it meant to be a way to open the circuit by scraping off ...
0
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2answers
83 views
I need some help understanding the schematics of DIY HS102 oscilloscope
I was looking on the schematics for the DIY HS102 oscilloscope by Martin Loren (http://hscope.martinloren.com/HS102-oscilloscope.html)
But I'm a bit confused about the role of the ASM1117 (LDO ...
1
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0answers
37 views
Guitar to iPhone JFET pre-amp circuit issue
I am following this tutorial to build a simple JFET pre-amp to connect a guitar to an iphone.
This is the schematic:
I have soldered the components as per the schematic directly onto the 1/4" mono ...
2
votes
0answers
29 views
24-60V Precharge schematic critique
I'm looking to design a soft-start precharge circuit for starting up circuits with substantial input capacitance (~1.5J @ 24V). The main requirements are:
24-60V compatible
Constant current pre-...
-1
votes
1answer
45 views
How does this circuit work (digital logic circuit?)
I don't really understand how this circuit works.
For example, suppose that Reset (Num 7) is 0, Thresh (Num 8) is 1, and Trig (Num 9) is 1.
After Y1 we get "1", after Y2 "1" too. And logic "1" ...
1
vote
1answer
65 views
How to drive a speaker with amplifier using 3.5 mm jack [closed]
I have two bare loudspeakers salvaged from old speakers and I would like to control them from computer using 3.5 mm jack. The speakers had a control board, but that is broken. I would like to ...
0
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0answers
32 views
ESP32 with LNA and PA
I would like to add a low noise amplifier and a power amplifier to the ESP32. As you may know there is only one RF output on the chip.
I was thinking of adding an RF switch, and switching between ...
0
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0answers
28 views
Using ESP32 and external WatchDog STWD100NYWY3F
I want to use ESP32 with the STWD100NYWY3F external watchdog timer. Below is my connection diagram.
On WDI with 33 pin, periodic pulses are sent to the watchdog timer.
If the timer is not reset, then ...
0
votes
1answer
31 views
AC Mosfet linear control
So I'm developing a circuit to control charge, discharge and balance LiPo batteries.
Supply voltage will be ranging from 7V to 25V, but not larger than max. Voltage of charged battery. (If I connect 2 ...
0
votes
2answers
87 views
What is the use of these resistors in the schematic?
I am trying to build a line-following robot with the schematics I found below. I understood that the comparator is used as the logic for the robot and there is no need for a feedback loop for the ...
0
votes
1answer
38 views
Transmitter / Amplifier matching
I am trying to add an amplifier to a transceiver to increase the range but I am not sure how to add the reference schematics together (eg what components to remove, combine, etc).
The top schematic ...
0
votes
1answer
47 views
Enterprise model blinkers - two fast flashes and pause for 3s and repeat LED circuit (with 555 and/or 556 and/or 4017) [closed]
I'm building a Revell Enterprise Into Darkness model with LEDs and I need help with circuit that makes two fast flashes, pauses for 3 seconds, then repeats. as seen in the movie. I have searched and ...
5
votes
3answers
878 views
What is a Power on Reset IC?
I'm making a prototype based on the W7500P reference design, the latest version (updated 6 months ago) specifies the need for a Power over Reset IC.
I do not understand the point of this component ...
0
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1answer
88 views
Is this an appropriate smps design? [closed]
I am an engineering fresh graduate with an interest in PCB design. I have been learning KiCAD which is really fun and I enjoy it alot.
A friend came to me with the reference circuit attached here and ...
0
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1answer
54 views
Checking my mpu6050 schematic
I am fairly new to pcb design and I just created a mpu6050 chip that will work with an Arduino microprocessor. I want to make sure the hookup is all correct before I start work on the other parts, as ...
1
vote
1answer
79 views
Faster refactoring in Altium Designer 19: Quickly converting a circuit fragment to a new sub-sheet
In the process of refactoring a large schematic sheet into smaller, more manageable, hierarchical sheets in AD19 I have the following process:
Create a new schematic sheet for the sub-circuit and ...
0
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0answers
138 views
Could i get some circuit design feedback?
I have a computer science background and this is the first circuit I've ever designed. It is a lot of fun designing these circuits, but it also always feels like I'm missing a lot of "obvious" common ...
0
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1answer
34 views
Notation for switches in ladder notation
I was reading https://www.allaboutcircuits.com/textbook/digital/chpt-10/monostable-multivibrators/,
and at the bottom of the page it has
I read their page on switch notation, but it did not say what ...
1
vote
2answers
113 views
ESP32 powered by supercapacitors
It's been ages since I had to design something electrical so please don't laugh if this is stupid idea but I would like to power ESP32 with super capacitors, just for 30 sec or so so it can finish the ...
4
votes
2answers
1k views
Learning how to read schematics, questions about fractional voltage in schematic
In a schematic I've been reviewing I see in only one spot that there is a 1/2v going somewhere? What does that mean?
simulate this circuit – Schematic created using CircuitLab
0
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2answers
121 views
Butt splice electrical symbol
I'm making a detailed electrical diagram which needs to include splices. From researching on Google I couldn't find the conventional symbol for a butt splice, or even a splice, in an electrical ...
0
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0answers
26 views
CircuitStudio: How to connect zero-indexed buses to a repeat schematic sheet?
The general gist of what I'm trying to do (in CircuitStudio), is the following:
In a hierarchical block "input", I generate four signals that are to be fed to an array of sensors, one signal per ...
1
vote
1answer
61 views
Question about Roland 606 schematic
Hello this is my first post.
I have a question regarding the circuit diagram of the Roland 606.
I'm currently redrawing the hihat circuit with noise unit.
The symbol behind R6, and elsewhere in the ...
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0answers
68 views
Help identify RJ11 pins on a relay board - No152133
I'm tinkering with my garage door motor (Marantec Comfort 220) which have a RJ11 6-pin connector (X10) for an accessory relay board.
The board consists of three (3) relays driven via the RJ11 ...
2
votes
2answers
159 views
What is the correct schematic symbol to use for virtual ground?
I'm following the design of a circuit requiring a power supply to provide something the author calls virtual ground, \$V_{gnd}\$. The circuit look like this:
However, I'm using KiCad for the design ...
0
votes
1answer
110 views
Will this capacitive discharge welder design work?
I'm an electronics newbie trying to learn about the subject through tinkering, and my current project is a capacitive discharge welder for welding on battery terminals. I thought I'd better have ...
0
votes
3answers
97 views
eagle schematic check [closed]
I will do basic IOT project with esp-wroom-32.
but I am machanical student. I need to help please check my design.
my component:
- esp-wroom-32
- button
- pad-resistor
- locig level converter
- ...
0
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0answers
51 views
How does recuperation works in BLDC?
Using BLDC wheels is common on electric transport. A wheel is a multiphase motor, where each phase(coil) is separated from power source(battery) with some kind of transistor, driven by PWM-like signal....
0
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1answer
92 views
Why is this power supply split?
I am looking at a schematic for the Pixhawk 2 board. It has a complex power distribution system (see photo below)
Much of the complexity exists for one of two reasons
redundancy
shutting off ...
0
votes
1answer
64 views
Connecting an IC to LEDs - would I use a transistor?
I have this breadboard circuit, which is basically a 65C02 CPU that has 16 Address pins. I want to wire these up to LEDs. Below, I've connected them directly, which is likely all kinds of bad (Too ...
0
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1answer
85 views
How to drive 2/3 color LED's and circuit schematic
I need to use 2 or 3 color LED for my circuit.(preferably 3 color one). I am going to use PIC18F26K83 to control the LED. However, I am confused how am I going to make it change colour. I think I ...
0
votes
1answer
31 views
eeschema: prevent Value, Reference from moving relative to symbol library?
When I create a symbol in the symbol editor and then drop it into a schematic, many of the fields (Value, custom fields) are automatically moved outside the bounding box of graphical objects.
In the ...
0
votes
1answer
30 views
How to properly use a shut pin in audio connector to prevent floating pins when disconnected
I'd like to use this RCA jack in a project that detects roughly the volume level on an RCA audio source. The circuit filters out the DC line voltage, amplifies it with a PNP transistor and then shifts ...
1
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1answer
165 views
Understanding 5V to 1.8V UART level-shifting circuit
Hopefully it's OK to ask very basic electronics questions here.
I had a TTL 5V UART cable, however the board I had only accepts 1.8V max. So I found some online schematics that uses resistors and a ...
2
votes
1answer
60 views
What is this contact on a jack socket schematic?
I'm looking for a 4-poles (TRRS) 3.5mm jack socket with integrated switch, and stumbled upon this connector schematic:
(this is an extract from the CLIFF FC68129 datasheet)
I understand that pins 1, ...
0
votes
1answer
57 views
How to diagram power-side and ground-side switches?
I'm an early-stage self-teaching hobbyist.
Just as a practice exercise I'm diagramming simple circuits (without looking at the instructions) of DIY kits that I've bought on banggood.com (awesome ...
0
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1answer
40 views
LCSC parts for Coil & Capacitor
Greeting,
I'm using This Schematic as a reference to create a customized BLE PCB board.
I need some help to identify the below parts (with LCSC part No. if possible) as this is my first time to see ...
8
votes
2answers
738 views
Schematic conventions for different supply rails
I have two ICs in my circuit. They have different supply voltages, 3.3 and 2.7 volts. The voltages are subject to change as we refine the design. I'm trying to come up with labels for these rails. One ...
1
vote
1answer
66 views
PSpice AC Circuit Simulation Showing 0 V for Output Voltage?
I am trying to run a simple Op Amp simulation. My lab gives zero instruction on PSpice, tossed us a brief manual on DC PSpice circuits (even though the class is AC), and said go forth. The circuit I ...
3
votes
1answer
302 views
Help understanding 1986 schematic for Rohde & Schwarz cryptographic key generator
From https://www.cryptomuseum.com/crypto/rs/pu104/index.htm :-
PU-104 was a key generator for perforated paper tape, made around 1986 by Rohde & Schwarz (R&S) in München (Munich, Germany). ...
0
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0answers
45 views
Designing a prototype pcb in Eagle with other parts imported?
I am protyping a project with several boards like microcontroller, charger, booster etc. for my bachelor's degree in electrical engineering. Now I want to switch from my prototype board and etch my ...
1
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2answers
64 views
Replacing elements in a tube amplifier
I assembled a tube amplifier.According to the specified scheme (Old Russian radio "Record 66").
1.What is the function of capacitors C9 and C8 ?
2.What will change the capacity of these parts? Will ...
