# Questions tagged [circuit-design]

For questions about the design of circuits. This may cover everything from processing steps to models to high level circuit design issues.

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179 views

I am having trouble finding a 3.4 µH through hole inductor that is in stock right now. I was wondering if I can just place 2 inductors that add up to 3.4 µH in series to solve this problem. I am not ...
259 views

### Simultaneously charging and transmitting data to an android phone using usb

Dear engineers, I have to make an engineering project which is a portable solar phone charger. One thing I need to do in it is to somehow charge the phone (android) from the battery (which is charged ...
428 views

### Units for rotational impedance

I'm trying to use the mechanical impedance analogy to describe a spring mass damper system as an electrical circuit. Mechanical Impedances for linear motion are  Z_{lin}(s) = \frac{F(s)}{\dot X(s)...
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3k views

### Square wave transfer function?

I made a mathematical model (transfer function) of a rlc circuit. I simulated it in matlab simulink with step input and square wave input and observed the result. I can also calculate this system with ...
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498 views

### Thermostat design properties

Cut-in, cut-out thermostats are commonly used with refrigeration devices in order to hold a consistent temperature range. Their general operations is such that when the temperature by the probe ...
452 views

### Arduino DAC to Speaker

I'm working with an Arduino Due's two DAC pins. I want to output to a single 4W 5.7Ohm speaker to test my code, with the intent of eventually outputting to a set of speakers (woofer, mid-range, and ...
283 views

### What does this Logic Circuit do?

So I have to analyze this circuit, with inputs C0, A0, B0, A1, B1, A2 and B2, and outputs S0, S1, S2 and C3. It's been suggested I don't use a truth table to figure it out. I need to find out what the ...
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135 views

### If I have multiple different DC voltage inputs, how do I get a stabilized output at an intermediate voltage?

Let's say I have $3$ DC lines input as $10 V (x A), 24 V (y A), 6 V (z A)$. Now I want to convert the output to say $16$ VDC at $k A$. What kind of converter can I use?
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1k views

### What controls the gain in a BJT amplifier, and why does this circuit have a gain of unity?

In the case of the first circuit, The ratio between the input voltage Vin and the voltage at the collector and the ratio between the input voltage Vin and the voltage at the emitter are supposed to be ...
60 views

### How to provide conditional locking to drawers?

I am designing a device in which I want to lock each drawer until it's time to open them. Let's say that there are 4 compartments in the device. Each compartment needs to be programmed to open at a ...
387 views

### Designing a Voltage Divider [closed]

I am struggling to solve this problem and my available time conflicts with my professors available time. Could any of you offer me some help, perhaps describe the method I would use to solve such a ...
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717 views

### How can I calculate overcurrent from over voltage for the AP9101C IC

I designed a battery charging, protection, and boost circuit for a project I am working on. However, I made a complete noob mistake and forgot to find the overcurrent value for the battery protection ...
47 views

### Comparisons of multiplier circuits

Could someone please explain some of the advantages/disadvantages of the wallace multiplier circuit vs a shifting and adding multiplier circuit vs an shift register multiplying circuit? We went over ...
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59 views

### Is there any hardware to use in GPR applications? [closed]

I want to make a radar system which needs to send EM wave and receive the reflected wave from the ground. I am looking for a ready to use RF signal processing hardware but can't be sure which is ...
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1 vote
145 views

### Electrical potential and grounding in a circuity, why it works?

I thought I understood the ground concept but now I'm a lot confused. From: Pg.67 Practical Electronics for Inventors - Scherz Paul As it's explained in the book, the first circuity is the one that's ...
1 vote
108 views

### Precisely control voltage output

I think the component name is a rheostat- is that what allows you to control the voltage output please? I want to control it in steps close enough to 0.1 ish volts? So I would like to attach a knob ...
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1 vote
85 views

### What are the charge/power connector of restaurant order pagers / buzzers called?

They look like snap buttons and used for stacking pagers for charging. Closest things I can find are socket screws and cap nuts.
1 vote
354 views

### Building oscillating magnetic field circuit

I wanted to create an oscillating magnetic field using an electromagnet which is rated for 12V continuous duty. I was thinking that I need an arduino to control the electromagnetic circuit by using a ...
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1 vote
53 views

### Designing RLC circuits at specific frequencies for teaching use

I need help designing simple circuits that resonate around specific frequencies. Basically I am looking for recommendations as to what size capacitor, inductor, and resistors I should get. Sorry if ...
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1 vote
27 views

### How do they get more signals simultaneously inside a node of a neural network? [closed]

Why the circuit does not freeze/lock when the signals SUM ? But the electrical signals are SUM together in what sense? This question is about neural network circuits because I don't understand what ...
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1 vote
235 views

### Designing a loaded voltage divider?

I was wondering how to design this circuit in depth, since I have no idea what to do.
1 vote
565 views

### I am trying to create an op amp based negative voltage regulator

I am trying to find simulate an op amp based linear regulator negative voltage regulator circuit. I have done the circuit for positive voltages, but does not know how to do it for negative voltage. ...
1 vote
207 views

### Adding an R2R Digital to analog converter inline with TRS connector

I am trying to create a simple R2R DAC, maybe 8-16 bits. I want to be able to that type of DAC inline to a headphone line. Since the an 8 bit R2R DAC will need 8 pins, how exactly do I wire up a TRS ...
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1 vote
78 views

### Can different analog and mixed signal devices be combined on a single chip

Say I want N-ADCs, M-amplifiers, K-filters, and why not, an oscillator too. Is there a platform to combine whatever device i need, and that this platform is implemented on a single chip? I know an ...
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1 vote
3k views

### No Voltage appearing on Pspice

I am trying to compelte this question, however when i run the simulation there is no voltage atall on the output votlage, and cahnging the capacitor value as requested in the question does not chane ...
1 vote
91 views

### Circuit that multiples two numbers together?

Design a combinational circuit that multiplies two numbers together, and outputs the result. The biggest product will be 3 * 3 = 9. Four bits to represent the product. ...
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1 vote
45 views

### What should be the clearance and creepage for the line to line 440 Vac and line to neutral 240 Vac of the three-phase system on PCB?

Also is there any link to calculate this as per the UL and other industrial standards
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1 vote
165 views

### Methods for External Antenna Detection - RF systems

I’m designing an RF device that should be able to use multiples sets of antennae, one a low-gain internal PCB antenna and the other an external high gain antenna attached via an SMA connector. I’d ...
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1 vote
532 views

### PC Controllable DC Power supply (0-30V)

I have a Proportional solenoid valve that uses a 0-30VDC for control (opening the orifice) I only have capability to provide 0-5V or 0-10V. I need to control the valve using my PC. Is there any DC ...
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1 vote
291 views

### Difference between a positive and negative adjustable voltage regulator (LDO's)

I am having trouble understanding the difference between positive and negative adjustable voltage regulators (LDO's). There are circuit diagrams for the positive LDO's such as the following: I am ...
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1 vote
276 views

### Calculating gain of an overall system. Analogue electronics

Our professor has given us a review for a upcoming exam. But he has never done anything like this question and it has stumped a quite few of us. We are hoping someone can walk us through this so we ...
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1 vote
2k views

### Percent (%) error between calculated gain and measured gain of FET amplifiers

I've recently been learning about FET amplifier circuits and I'm looking for some information that can help explain why the calculated and simulated Gain Values can differ by up to 15% in some cases. ...
140 views

What would happen in real life if you made a paradoxical circuit (a circuit whose output is on iff its output is off). Something like this: Would the discrete model break down and the output end up ...
4k views

### Is there current multiplier circuit?

Is there an electric circuit that can multiply the input current? if yes, what is that called, and how to make it? My input is DC from a small DC motor which I use as a generator. My input current is ...
52 views

### Why does a metastable state eventually resolve to a stable state?

I was studying with a book named "Digital design and computer architecture". When I read the part of metastability, it stated this without any additional explanation.. Why does a metastable ...
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149 views

### How to make motor spin the other way

Let’s say I want two motors in parallel in a circuit (so they get the same Voltage), and wanted one motor to spin anti-clockwise and the other clockwise- is it possible? I thought by flipping one of ...
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58 views

### How to Supply two different DC voltages using High Current

I'm trying to function a 12V stepper motor(>2.5A) and five 6V servos(>3A). Are there any reliable circuits that can output both these voltages and a high output current since there will be some ...
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41 views

### Explanation for photovoltaic circuit

My background is in Environmental Science, although I have recently been taught in the basics for energy engineering especially for solar panels. I'm currently using PVsyst to build solar panels on a ...
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322 views

### What signals are expected on the connectors for this 12V Volkswagen Scirroco wiper motor circuit

EDIT: added a picture of a very similar unit. I picked up a used VW rear? wiper motor that I want to use for a simple motion experiment. Having no idea how to power the thing I popped open the case ...
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60 views

### How to minimize ozone production while ionizing air?

Right now I am using nine components intended for home air ionizers in parallel, I'd like to build one big one. I've heard that if one keeps the discharge voltage at -4kV, this produces negative ...
155 views

### Is learning VLSI design useful for a control/automation engineer?

I've known of a few universities that include a class about VLSI design as a part of their control/automation engineering programs. I undestand VLSI design to be about creating integrated circuits ...
619 views

### Utilize multiple vehicle power outlets to increase wattage capacity of inverter

I'm trying to determine whether it would be possible to use multiple power outlets in vehicle to increase the wattage that can be obtained. This question is driven from a desire to install an DC to ...
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13 views

### CMOS AC-to-DC Converter Design

I am trying to analytically model the power conversion efficiency of an AC-to-DC power converter circuit (see Figure 1). In this design, the drain-source voltage of each MOS device can be expressed as ...
51 views

### Strange problem with Impedance?

I've encountered a strange problem with a 12V key-fob device. We use a device to remote control a relay via a key-fob transmitter. It's installed in a plastic box that is mounted at an operator ...
32 views

### How do I draw a circuit for a conducting loop inside a solenoid?

To solve a homework problem, I need to redraw the following diagram in circuit form. The large blue circle represents the solenoid. Inside the solenoid, the two gray semicircles represent a wire loop,...
31 views

### How to build a 4-bit full adder that shows result on 2 7-segment LEDs, without using Arduino?

I'm required to create a 4-bit full adder (ALU actually), that displays result on 2 7-segment LEDs with both are common cathode, using only 74HC283, CD4511 and some other logic gates. I'm confused on ...
18 views

### Building drone transceiver module with 2 recievers onboard to switch gates ON/OFF to turn motors On/Off

I'm looking for any resource that can help me build a radio (no infrared) controlled circuit with two receivers onboard a drone. The purpose of this circuit is for research and education. Whenever ...
182 views

### Voltage at node A respective to the ground

I want to calculate the voltage at node $A$ respective to the ground. $R_1=1.8\text{k}\Omega, R_2=3.8\text{k}\Omega, R_3=1.8\text{k}\Omega, R_4=5.8\text{k}\Omega, R_5=2.4\text{k}\Omega$ and \$V1=4.3V, ...