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Questions tagged [circuit-design]

a term to describe how a circuit should behaved based on accomplishing a particular task. When designing circuits, one should consider how it works, the target specifications, efficiency, cost effective, code compliant, and ethics.

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2answers
50 views

Running case fans on D cell batteries

I'm moving into my car and I may need to wire up ventilation that doesn't depend on the engine running. So I found these case fans. However, because I'm not going to be using the car battery, I need a ...
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1answer
39 views

Non inverting amplifier oscillations

The point of this circuit is to take a 300 to 400 kHz 5Vpp square wave signal and convert in to a sinewave of the same frequency amplified with a gain of 2. The filtering before the op amp seems to ...
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0answers
34 views

how to Detect if AC appliance is powered [on hold]

Hello I'm not an engineer but I know some basics of electricity and can install relay etc. My question is that I want to turn on an indicator when my air conditioner turn on. I have read on google ...
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1answer
28 views

Battery removal circuit via interruption

I am designing to detect battery removal with minimum current. I tried some designs that I expect interrupt when battery removal, but the port of my MCU was floating. If I design like circuit in the ...
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0answers
66 views

How are PCB stickers similar to Chibitronics made? [on hold]

Chibitronics makes sticker circuits. They appear to be circuits printed and fabricated over copper tape. How are these circuits made. Is there a word in industry for these circuits ?? Where can one ...
0
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1answer
17 views

How to get the Forward voltage of a tachometer?

I am currently in the process of building a circuit board for components that I am going to use on a lathe. I want to use this tachometer. https://www.amazon.com/dp/B00VKAT8A2/ref=...
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0answers
45 views

Explain The Radio Receiver Diagram [on hold]

Hello I am curious about radio. But I don't know how a capacitor, diode, amplifier and receiver works in radio. I want to know how they work technically. For example, describe the components using ...
0
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2answers
59 views

Help me understand what happens with the circuit when an AC signal is applied

Consider this circuit. Transistor is 2N2222A. Ic is chosen to be 10 mA. Hfe is 225 for that current. Resistors are calculated to have Vbe = 0.7V and Vc = 4.5V. I am trying to understand what happens ...
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3answers
212 views

Where to find proven design patterns? [on hold]

When developing software, it's recommended not to reinvent the wheel but to use battle tested libraries e.g. for sorting or proven design patterns like the GoF. However when it comes to electrical ...
2
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0answers
67 views

Biasing high frequency BJT cascode amplifier

So far, no one in the course has gotten both primary spec: 14.125 (with 1 V/V swing either way) nor 3dB-bandwidth of 500kHz to 20MHz using the 2N4427 (datasheet). Vcc = 9V I_CQ = 10mA-15mA I have ...
0
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3answers
104 views

Connecting multiple Fairy lights in parallel to single power source

The above diagram shows how I'm about the connect the LEDs, info regarding the drop forward voltage been taken from: Calculating forward voltage for a string of fairy lights: multimeter shows "1&...
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5answers
10k views

Why is the time constant 63.2% and not 50% or 70%?

I am studying about RC and RL circuits. Why is the time constant equal to 63.2% of the output voltage? Why is it defined as 63% and not any other value? Does a circuit start working at 63% of output ...
1
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1answer
49 views

Integrator circuit time interval

I am designing an Alpha particle time of flight detector which consists of two scintillators separated by 5cm of vacuum (few Torrs). The two scintillators are connected to two separate avalanche ...
0
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1answer
36 views

MagJack for PoE Powered Device

I am adding Power over Ethernet functionality in my Toradex's System-on-module (Colibri iMX6ULL) based carrier-board design. I ...
1
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1answer
64 views

PoE and Adapter Power Supply Design

I am designing a power supply cicruit. The circuit will get it power from PoE (preferably) and external adapter (7 - 12V). For ...
1
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1answer
54 views

Clarification on solder mask aperture in PCB?

I'm using a 0.5 mm pitch FPC connector in my circuit. I was using a DRC with a 4 mil stop mask value. This resulted in a stop mask layer in Eagle (tstop) that looked like the one below: Based on my ...
0
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1answer
35 views

Which of these board designs is more suitable for a high current circuit?

I'm creating a DC-DC switching buck regulator using the LM2596 5A regulator from texas instruments to convert 12V@3A to 5V upto 5A. Since this is a high current circuit to feed servos, I've tried to ...
2
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0answers
75 views

ignition timing light trigger current

I've built an ignition timing light, following: http://citroen.tramontana.co.hu/en/ignition/stroboscopic-timing-light here the original schematic: I've changed some components: Instead of the ...
6
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2answers
899 views

What are these wires on single-sided PCBs? [duplicate]

I have a few questions about this PCB, namely the wires across the visible side: I am new to electronics. Would these wires be considered a "trace", "jump", a "via", or something else entirely? How ...
2
votes
2answers
92 views

Routing thick high current traces to small SMD pads?

What is the best practice for routing high current traces through the pads of small 0603 components? I have a wide high current trace which that passes through a 0603 decoupling capacitor. Initially ...
1
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3answers
79 views

How many capacitors are needed for a step down circuit?

I'm tyring to build my first step down component using TPS562219 to get 5V output from a 12V input (instead of 1.05V output shown in the example). But as I'm new to this electronic stuff, I have some ...
2
votes
1answer
48 views

RC-circuit with one input terminal and many outputs with different integration time

What is the simplest way to create an RC-integrator with one input terminal and several output terminals which differ their times of integration (see schematics below). simulate this circuit –...
0
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1answer
45 views

Current Ramp with constant voltage.

I am trying to figure out a way to make a ramp (0A - Amax) with a constant voltage. Basically I have a SPST switch that is connected to a 24VDC battery. I need a ramped current output from 0A to 1.9A. ...
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1answer
120 views

10MHz Sine Wave Generator

I have been looking for some time for a good design for a ~10MHz sine wave generator, with variable frequency from about 5-20MHz. The max required peak to peak amplitude is 10V. Many suggestions on ...
0
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2answers
195 views

Safety design on mains detector

I've designed a simple mains detector which I have drawn below. The theory of operation is pretty simple. A capacitor is used to reduce the current so that my optocoupler can operate (represented by ...
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0answers
33 views

Creepage Distance in Altium Designer

I have a design with a high voltage and a low voltage part. Between the two I need to have a creepage distance of 8mm. Some optoisolators I use in my design are not wide enough on the PCB footprint, ...
1
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1answer
29 views

Can a photodiode tolerate a reverse bias beyond its specification

While searching a literature related to my experiment I come across this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4424026/pdf/PP_PP201500119.pdf . On the page 27 under the section SRS ...
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1answer
50 views

How can I use a comparator in a circuit?

I am learning about how to use Operational Amplifiers as comparators. I understand that comparators are used to compare an input signal to a reference voltage. However, I am having a hard time ...
0
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1answer
33 views

How to pick a voltage comparator switch for a low power circuit

I am finishing up an embedded project for my vehicle and the last step is to make it automatically power off with the car. The way I detect whether the vehicle is on or not is via a battery pin, which ...
0
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1answer
28 views

switch 3 references voltage for my servo position

I have some positioning servo driver and servo with pot feedback. Now I try to build circuit to switch between 3 positions. For testing I just use 3 way switch and 3 pots as voltage reference, but in ...
0
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1answer
37 views

IN/OUT pin of the crystal circuits [duplicate]

Got few questions about the input/output pins of a crystal circuit. As shown above, it's a common clock circuits. My question is: 1. If we want to measure the waveform of the clock, which pin should ...
0
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3answers
84 views

48VAC analog waveform [closed]

I want to make a circuit to drive out a 48VAC 10mA 60Hz sine wave signal. I was thinking that I could generate a waveform with a microcontroller to feed it to an opamp then to a audio transformer ...
1
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1answer
96 views

Circuit operation and component substitution questions for stroboscopic timing light

I'm trying to make a piece of circuitry, for a tool used to set the ignition timing of my old car. I've found the schematic and description here: http://citroen.tramontana.co.hu/en/ignition/...
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1answer
48 views

Negative Voltage Generator for Low Voltage ( +1V ) Input

I am working on an analog circuit. I can only use a +1V power supply. My design requires a negative rail, so that my level shifter will work. Attempts: I have already seen Build Your Own Negative ...
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0answers
22 views

Oscillator circuit based on a SAW delay line

I was hoping someone may be able to point me in the right direction for a oscillator circuit that depends on a SAW delay line for control of the frequency. The SAW central frequency is 20 MHz, for ...
2
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1answer
84 views

Programmable Electronic Load Design

I am trying to design a programmable electronic load for testing the PWM outputs of PLC controllers. The outputs operate between 5-36 V and 10-2000 Hz frequency. The output is supposed to tested for ...
1
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1answer
68 views

Fire danger when using IoT components

I am automating my house using components like ESP8266, 220 to 5V converters, relays etc. How big is the risk of a fire starting from a component malfunction and how can I mitigate this? What should ...
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0answers
46 views

SystemVerilog: VCS detect combinational loop

first of all I'm still learning English so thanks for your patience I'm debugging a large code, I did a testbench for every module and I think they work as intended but when I connect them together ...
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0answers
51 views

Test Equipment for generating large voltage spikes

I am trying to test a tachometer circuit which takes large voltage spikes from an inductive pick up and conditions them for TTL logic. I need input voltages in the order of 200V peak-to-peak but most ...
0
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1answer
65 views

Why is this MOSFET Differential Pair On on the Right-Hand Side?

Could someone please explain to me both the qualitative and quantitative analysis of the following MOSFET differential amp circuit, to explain why Vs = -0.5 V and the Right-Hand MOSFET is "on"? EDIT -...
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3answers
87 views

What exactly lies between an HDL and a circuit?

I'm trying to learn basics of hardware design process to get a better understanding of how CPUs, microcontrollers etc work and how are they made. My googleing gave me many articles with info like "...
4
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5answers
188 views

Noob questions: I'm confused about conventional current and electron flow and how it runs through and powers a circuit. Can someone please explain?

My apologies if these questions have already been asked and answered, if it has then I haven't found the thread so please link me to it if it exists. I've just started learning about electricity as I'...
2
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2answers
33 views

Slow build-up and discharge LED effect

I was trying to build a circuit that if switched on would slowly (in span of of 1~5s) light up around 20 LEDs - progressively, not all at once. To achieve that i used one capacitor to initiate the "...
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0answers
23 views

Need help in designing circuit with LT1959

I have to make a regulator circuit with 4V output using LT1959 switching regulator. Its mentioned on page.2 of Demo manual below DC356 circuit diagram] that "MOVE D3 TO POSITION D2 FOR OUTPUT ...
0
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2answers
31 views

RGB LED common cathode with 3.3V GPIO +single transistor

You can control a RGB common anode like this with only one transistor and 3.3V GPIO sources: How can you do this with a common cathode LED array using only one transistor per LED and 3.3V GPIOs? The ...
2
votes
1answer
39 views

How long can a brand new PCB last before additional protective coating is required if any?

I have just made several PCBs for a large project using the photoresist method. (I ran the boards through sodium silicate developer then through ferric choride) I then rinsed off all chemicals and ...
2
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1answer
63 views

How to add a LED to a Multimeter for use it with the buzzer in continuity testing?

I want to add a notification LED to my digital multimeter which i need to glow with the multimeter`s inbuilt speaker (piezo/buzzer/beeper) while in Continuity testing mode. MM Model : DT830D If i ...
3
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3answers
95 views

High Voltage ADC Measurements using a PIC and OpAmp

I need to make a device to measure voltage of a series stack of capacitors which will reach a maximum of 100V (DC only). On the schematic I have omitted several from the stack, balancing circuitry ...
0
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2answers
74 views

How can this capacitator discharge? (Make: Electronics experiment 9)

I am trying to get through Make: Electronics book and I cannot understand, how does capacitor in following circuit discharge when I press B button. Wouldn't the current just go in the circle that ...
0
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2answers
53 views

How to limit the output voltage of a TCXO?

I am using an SiT1552 MEMS TCXO providing 32.768 kHz. It will be sourcing two ICs: a microcontroller and a DA14580 Bluetooth Low Energy transceiver. The ICs and TCXO are all powered by 3.3V. The TCXO ...