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0
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3answers
45 views

How to measure the resistance of digital potentiometer AD5241 in circuit when power on

I have designed a transimpedance amplifier including a digital potentiometer AD5241. The circuit is showed below. I want to test the AD5241 to make sure it works as designed. simulate this ...
0
votes
2answers
73 views

Draw a finite state machine for a welding machine

I am trying to draw a fsm for a welding machine. So far I have the following table, which I think is right.. The system has three normal states: stopped, started, and welding. It will only transition ...
0
votes
1answer
39 views

Laser activated switch using a photo-transistor

I would like to make a laser activated switch using a photo-transistor or an LDR, by which I can switch off the lights in a room from a long distance. I just have to point the laser and it will detect ...
-1
votes
1answer
42 views

How to Control a 3D Printer Extruder [on hold]

I am trying to control a 3D Printer Extruder that I got online. I know that for the most part, a person would just plug this in to a circuit board and it would just work. I want to make my own circuit ...
1
vote
2answers
74 views

Variable Voltage Using PWM and Low Pass Filter

I am trying to control a steady DC output voltage using a Micro controller with a PWM duty cycle. With the current schematic, the Voltage on Vout is pulsing along ...
-1
votes
0answers
32 views

LED strip flashing to music

I'll give you the backstory: A few weeks ago, I used a popular enough circuit to create LED lights that flash to music. The circuit I used as a template is the first image in the imgur album ...
2
votes
2answers
142 views

circuit protection feedback

The is the simulated version of the schematic. I have designed a protection circuit for my pcb and I would appreciate having some feedback before starting the PCB design. The circuit is broken down ...
0
votes
1answer
52 views

I would like to ask if my answer to this simple circuit is correct

The problem is to find the values of Vx and i3. I was reviewing DC using KVL and KCL and I would like to check if I got the answers right!
3
votes
1answer
161 views

PCB design: the setting of the test point and the use of variable resistor

I am designing a PCB circuit and meeting two problems: My design includes a two-stage MFB band pass filter. To make sure the center frequency of the filters is the same, I need to add a variable ...
0
votes
1answer
73 views

Exact (accurate) and cheapest Second Signal Generator circuit

Sorry, this is my first question. I want to create a watch (clock) with needles, but I want to create a circuit to generate the second signal (not labview, not software). I need to know the IC's ...
0
votes
2answers
83 views

Switching Regulators in Series

looking for some help regarding switching regulators for a personal robot project. The problem: I have: two 18v 4.5Ah batteries (which when fully charged are actually more like 21v) I need: 5v/1A ...
0
votes
2answers
42 views

What potentiometer should I use for my led strip?

I have a led strip, this led strip is consuming about 2.5A @ 12V. Before, I was using an Arduino to modulate the intensity of the light with PWM but I realized that a simple circuit would be even ...
1
vote
1answer
31 views

Help finding maximum power transferred to load RL

This isn't homework, it's just a review problem. The answer is 4mW. I tried working the problem and came up with the wrong answer. What did I do wrong, and how can I solve this correctly? My ...
0
votes
3answers
69 views

Diode in parallel with two DC sources

Please help me to find the answer for the following question from Flyod 9th Ed. Determine the voltage across the diode in the following figure, using the complete diode model with r'd = 10 Ohms and ...
2
votes
5answers
553 views

How to blow a 0.6 ampere fuse

I am trying to do a simple project in which I am trying to show that when a high voltage battery is connected in a circuit then the fuse will blow and protect other appliances. In detail, I have four ...
2
votes
1answer
121 views

How can I control a 120v, 1amp fan with a Nest thermostat?

I have a fan (hot, neutral, ground) that requires 120V and uses 1amp max. I'd like to be able to control this with a thermostat so that the fan turns on when the temperature is above a certain set ...
2
votes
4answers
213 views

Need help explaining this circuit and how it is dimensioned and designed

I'm working on a project to school where I'm designing a battery charger with battery status indicator, and I found this circuit online: but to include it in the project, I must explain how it ...
3
votes
3answers
55 views

How to correctly connect audio plug to LM386?

I'm working on my first circuit which includes LM386 chip and some music. Since I don't have a lot of experience with electronics I need a little help with audio plug. It's the same as that: I know ...
2
votes
2answers
47 views

Separating / Isolating the circuit blocks

I was designing the circuit of a superhet receiver, block by block. Needless to say, my concern is how would I separate the various blocks. In other words, how would I interconnect the blocks ( not ...
1
vote
1answer
48 views

Monitor if circuit is open or closed?

I'd like to design a simple device that uses a microcontroller (in my case a TI Tiva C Series Launchpad) and a relay to drive a load, then monitor whether the load is actually drawing any current. ...
0
votes
1answer
41 views

Color Changing LED Circuit upon power on

The circuit I plan to make will have 3 RGB LEDs in it and what I would Like is for it to change colour each time it turns on to a random colour. I'm a beginner level so any help will be greatly ...
0
votes
1answer
59 views

Female Rectangular Headers with Long Pins (Pass-through style)

Female Rectangular Headers with long pins (passthrough style) are used to stack/connect an Arduino shield board to the Arduino board. 1x8 and 1x6 position headers are easily found. Problem: However ...
0
votes
1answer
34 views

phasors and differential equation circuit analysis?

I am having trouble, the steady stae voltage i find by differential equations is no the same as the one i find by phasors, what is worng? \$V_{ss}(t) = \cos(4t)\$ volts ........ by diff eq, ...
0
votes
0answers
72 views

Equivalent circuit of resistor capacitor

I came across a capacitor that has a marking like this: 0.1uF+2x2000pF XY + 2MOhm 220V~ HPF fo 1.6MHz 7.75 560.7 it looks like this one below the only ...
0
votes
0answers
29 views

Breaking down currents into mesh currents?

I have drawn a circuit above, but instead of components, I've just drawn squares to act as black boxes for components. In this hypothetical circuit, say the currents are as indicated in the ...
0
votes
1answer
58 views

Connect two boards together after removing Screw Terminals

An adapter board (to a card edge connector like PCI Express x1) is needed to be designed to for the breakout board below. This should involve replacing the board's screw terminals with some male ...
0
votes
2answers
46 views

Finding load resistance to achieve max power transfer

1) So, to find Thenevin equivalent resistance, R-Th, I disconnect R_L and disable the voltage source by shorting it out. ...
1
vote
2answers
44 views

A question about superposition and zeroing condition

Hey I couldn't do this question for my school and I'd be grateful if you help me. The question is: Calculate the voltage Ux circuit below. Specify zeroing condition of the Ux indicated in the figure. ...
0
votes
2answers
85 views

Find x cubed with half adder

My excercise is the following: Make a circuit which outputs X^3 of two bit input of X. Use the lowest number of HALF ADDERS as you can. I don't really understand ...
0
votes
1answer
29 views

Finding the Current I1 using Polar Notation

For the circuit in Figure Q3. Convert all voltages and currents to the form X sin(t + φ ). You need only find the stead-state solutions. Solution My Steps ... It seems that I am going along ...
0
votes
1answer
45 views

Sum 4 numbers, 1 bit each, with three full adders

My excercise is the following: Make a circuit which sums 4 binary numbers, one bit each, with three full adders. My solution was the following (sorry I can't ...
-2
votes
1answer
66 views

How can I add a second fan to this circuit? Directly control the fans?

I want to add a a second fan to my laptop. On its mainboard there is just one fan connector but there are also 3 exposed contact points nearby. Could I somehow use them for that? JFAN1 is the exposed ...
0
votes
1answer
50 views

Need help finding my mistake using Thenevin's Theorem for this circuit (not homework!)

So I have the following circuit (an example from my textbook). The answer for V_o is 3.88V. I got the wrong answer and I'm not sure where I went wrong. I know I could solve for V_o using other ...
6
votes
2answers
323 views

What is purpose of components in this circuit

I'm trying to understand this circuit but I can't understand purpose of R4 and R6. Can someone explain their purpose?
0
votes
1answer
63 views

Analyzing Opamp circuits

I was asked to analyze this Op-amp circuit and I need a little bit of advice about it. I have presented my analysis about the circuit, kindly correct me wherever I am going wrong. simulate this ...
-1
votes
1answer
71 views

Is white residue on a mobile phone water damage indication

I have bought a Samsung Galaxy S4 mini that burnt from the charging point. When sent to get repaired, they told me it was water damage. Illustrating in a picture some white residue circling a black ...
0
votes
1answer
58 views

Do I have to use a sense resistor? MC34063 Step-Up

Do I need to use a sense resistor for the MC34063 Step-Up Circuit? I would like to step-up my voltage from 5V to 40V. After doing the math, I've found that I will probably need a 0.16 Ohm Sense ...
1
vote
1answer
64 views

How can I create a DC-DC voltage multiplier [duplicate]

I want to take the 5V output from a USB port and make it 12V, so that I can run a cooling fan which is 12V. Is there any circuit I can make at home myself? If the output voltage is not exactly 12V, it ...
0
votes
2answers
78 views

Using Linearity, how can I find Vo in this circuit? (not homework)

I am making the assumption that Vo is 1V. Moving right-to-left through the circuit, I want to use that assumption to find Vs. Then, the ratio of the real Vs to my found Vs will be the same ratio ...
0
votes
1answer
62 views

Measuring voltage output in a voltage divider

I'm currently working my way through Electronics for Dummies, where I am shown a simple voltage divider circuit consisting of a 9V battery and two resistors, R1 (12,000 ohm) and R2 (15,000 ohm). ...
0
votes
2answers
177 views

Ohm's Law for voltage divider

I'm currently working my way through electronics for dummies, where I am shown a simple voltage divider circuit comprising of a 6V battery and 2 resistors, R1 (220 ohm) and R2 (1000 ohm) in series. ...
-1
votes
3answers
75 views

How to design a circuit using inverting op-amp when input-output relation equation is given?

Like this: $$V_0 = 5V_1 - 3V_2 + \frac{V_3 + V_4}{2} - V_5$$ I know about the transfer function but I am not able to make circuits from these relation and I am not able to find it in any book.
1
vote
2answers
92 views

Battery Voltage Sensing Circuit (Voltage divider, buffer)

I've been trying to figure out a quick and easy circuit for sensing a battery's voltage, then translating that voltage to an 0-5v signal that could be read by a microcontroller like an Arduino. My ...
1
vote
1answer
54 views

USB port suppressor

I am using SN65240PWG4 USB PORT SUPPRESSOR. This is a part of the schematic: (I have connected pins A (6) and B (8) to D- and D+ USB pins. C and D I must connect to the supply) In this schematic ...
0
votes
1answer
64 views

Instructions on building CMOS camera wifi video transmission [closed]

I am not sure this is the appropriate place to ask this kind of question, but I believe this is the best community to ask. I'd like to learn how to build my own circuit that would be capable of ...
0
votes
0answers
40 views

What is a good fundamental explanation for dependent current sources?

As in how one would explain to a student? Dependent current sources are slightly challenging to explain and are easy to over complicate.
1
vote
3answers
91 views

How to deal with grounding and the capacitors in this opamp schematic?

Here is a schematic I'm planning to make (right click on the image and 'open image in new tab' to see it better'): I have a transformer and AC to DC converter that makes +/-12V. (1) Does 'power ...
0
votes
0answers
49 views

How to bias a MOSFET folded cascode transistor using a cascode current mirror?

In the given picture how the folded cascode present at the output is biased. The method used by the author is direct voltage source biasing, but I wish to use a cascode current mirror but facing a ...
0
votes
2answers
141 views

How to replace this NPN transistor with a MOSFET?

Here is the schematic of the circuit I'm trying to build (source) but I only have an IRF9530N Mosfet; I don't have any NPN transistors at hand. What would the schematic look like with a MOSFET ...
0
votes
2answers
119 views

Open circuit voltage

I'm not sure how I go about finding \$V_0\$ in this circuit. The current source just confuses things for me. \$R_1\$ = 10 kOhms and \$I_g\$ = 17 mA in this example.