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0
votes
2answers
24 views

Circuit for a DC motor with 2 microswitches reversing direction

So here is what I am trying to do... have a DC motor wired to an on/off switch and 2 microswitches. Each switch will reverse the direction of the motor, so one switch tells the motor to go forward, ...
0
votes
1answer
20 views

Find four current mesh

I have to find the 4 current mesh in this circuit V1= 12V R1= 1/12Ω R2= 1Ω R3= 1/3Ω I1= 6A R4= 1/3Ω R5= 1/2Ω R6= 1/13Ω I2= 6A I tried a source transformation and got this I3= 144V R1-2= ...
0
votes
1answer
60 views

How these circuit diagrams in the datasheet was made? [on hold]

I've seen so many IC datasheets, and so appreciate the elegant reference circuit diagrams they've made. I'm not meaning the 'function' of the circuit, but the 'beautiful' schematics itself, such as ...
1
vote
0answers
24 views

Circuit with coupled inductors, need help with mesh equations

Are the mesh eqations in the image below correct? It gets a little tricky with the mutual inductance and my textbook gives no solution (American textbooks..). Click the image below for a larger view. ...
0
votes
2answers
76 views

How this circuit works?

Recently, i see such a circuit in a board schematic, but can't figure out how it works, why the first Op Amp has positive feedback ???? Thanks.
1
vote
2answers
59 views

How does one reuse a thick film circuit?

I have a thick film circuit from a calculator that I want to use. How can I attach external connections to the sheet? I tried simply using the circuit as a contact in between a battery positive and an ...
1
vote
2answers
99 views

Problem related to semiconductor?

Ok so this is the question along with its four option given in my text book I can't figure out what the answer should be as it is not stated that is the semiconductor forward biased or reverse ...
0
votes
0answers
71 views

What kind of circut is needed to wire multiple 12 volt power supplies in parallel?

I would like to build a circuit to allow multiple 12 volt power supplies to share a load. Each supply is rated for up to 100 Amps @ 12 Volt output what kind of circuitry do I need to achieve this ...
0
votes
1answer
27 views

Using Thevenin's Theorem?

Say your trying to find the Thevenin equivalent of a linear circuit with dependent and independent sources. You would find \$V_{OC}\$ (voltage across the short circuit) and \$I_{SC}\$, the source ...
1
vote
1answer
62 views

Proof of Thevenin's and Norton's Theorem?

Googling this gave me a number of proofs, but almost all of them assume the load is a linear component. Could someone give me a proof for these theorems assuming the load can be anything (a linear or ...
-1
votes
1answer
59 views

Am I doing this right? (LED's to music)

simulate this circuit – Schematic created using CircuitLab I have been charged with designing and making a circuit that makes LEDs brighten or dim to an audio source. At the time I ...
0
votes
3answers
98 views

Voltage across a resistor?

simulate this circuit – Schematic created using CircuitLab What would the voltage across the resistor be? What would its polarity be? I don't see anyway for KVL to not be violated.
0
votes
1answer
39 views

Battery Voltage is not as it should be when connected to ckt

I brought 6F22 9V battery. One's output voltage became nearly 6 volt after some use.But when I connect it with a MCU ckt , It gives only 3.37V as output ( voltage tested directly from the battery's ...
0
votes
1answer
96 views

Why can I have the positive and negative at the base of a transistor at the same time?

I am reading/doing the make electronics book and I am having a hard time in understanding how is it possible to have the positive and negative poles connected (even with a resistor) to the base of a ...
2
votes
1answer
74 views

Two power sources, auto-switch?

Quick question (hopefully!). I'm new to electronics, but getting quite interested. Coming from a programming background, it's always interested me... Anyway. I have a circuit with two DC Power ...
0
votes
1answer
33 views

Implementing a function with 4 inputs with 2x4 decoders

I'm a bit confused on how it is done. In the pdf we were given it only showed the solution, no explanation whatsoever. My guess is in order to implement 4 inputs with 2 input decoders, the decoder ...
0
votes
0answers
69 views

To reduce the resistance

In the circuit I need to find out equivalence Resistance. I have applied the Kirchhoff theorem and but these look too broad and might take too much time to solve. Is there any easy way to solve ...
2
votes
1answer
60 views

oscilloscope time charging different from the math

For the above circuit, I calculate that the equivalent resistance of the charging circuit is 2.668 kΩ, and the equivalent capacitance is 2.055 µF. Therefore, the time constant would be ...
-2
votes
2answers
80 views

Is a bus bar needed?

For a short period of time, 10 kA must flow in a circuit, is a bus bar needed? I mean, since the flow of current duration is less than 0.010 seconds on a certain wire?
1
vote
1answer
173 views

What is the symbol on the supply voltage that looks like a shaded-in capacitor?

I am looking at a datasheet for NJM2073 (dual low-voltage power amplifier). On the fourth page, there is a sample circuit; right at the V+ input there is a symbol that looks like a capacitor. However, ...
1
vote
3answers
82 views

Fallback electronic circuit

I've got a 220 volts fishbowl pump that is conected and working 24x7. However, when a power outage happens (they happen often where I live) I need to switch to a 12 volts version of the same pump, so ...
1
vote
1answer
57 views

Trouble with phase locked loop: phase comparator is just showing the VCO output (with picture)

I am using the CD4046BC for the first time, and do not understand something that is happening. I am using the type I phase comparator, which is just a simple XOR logic gate. When I have the input as a ...
0
votes
2answers
73 views

How to make a push-to-break circuit

So, I can get push-to-break switches that will break my circuit when pushed in. I assume this is how the light in my fridge works. But how do these works? I would like to make something like this, ...
0
votes
1answer
86 views

Design a combination circuit which can detect prime numbers from 0 to 15?

No idea how to attack this question, full question being: "Design a combination circuit which can detect prime numbers from 0 to 15. There should be a single output line, which would be 1 if the ...
1
vote
1answer
36 views

EMF in an Open Circuit?

Lets assume we have a wire passing a magnetic field, it is know that EMF is induced due to the magnetic field, what if the wire is not connected to a circuit what happens? Is there ay voltage in the ...
0
votes
3answers
78 views

Movement of Electricity in a Simple Circuit: A Few Simple Questions and a Diagram

The diagram above is of two batteries a light bulb and some cables. A book that I am reading shows that electricity would not flow through the blue cable, it would flow through the red cable. This ...
0
votes
0answers
25 views

i do not understand what current actually is? Is it stream or wave ? [duplicate]

I am taking circuit analysis but it is just theory and they do not give enough explanation to understand what current or electricity actually is
0
votes
3answers
59 views

Inverting Amplifier Not Giving Gain of -2.2

A LM358N op amp is used with R_f = 220k and R_i = 100k, which should give a gain of -2.2 in ...
1
vote
1answer
110 views

smoke fire alarm circuit and relay SPDT

I want to put relay SPDT in the output of the below circuit to connect with circuit working in 12v. when the buzzer run the relay switch on or off to another circuit automatically I want to run it ...
1
vote
1answer
129 views

Is there a limit on the charge that can flow in a wire?

I assume when I hook up a 12V battery to a wire, all the free electrons in the wire move. If I hook up 24V, they move faster so more charge passes a area cross section for i=C/s. But in AC, their ...
0
votes
1answer
57 views

How do you find the equivalent voltage of the current source in this circuit? [duplicate]

The circuit is shown at this schematic. How do I find the equivalent voltage of the current source by simplifying the circuit?
-5
votes
2answers
97 views

Equivalent circuit?

Can I simplify this circuit to just one resistor? How can I find the equivalent voltage of the current source in this circuit?
1
vote
3answers
65 views

Converting a circuit from Multisim into a PCB

I drew this metal detector circuit in Multisim. How can I make a PCB board from it? Is there an option in Multisim to convert it to PCB or do I need another program?
3
votes
3answers
163 views

Maintaining a constant current with varying loads

I've designed a constant current source using a current mirror, we need an output of about 50mA. The problem is that we build it and heat has become a problem.The transistors and the R_load are both ...
-2
votes
2answers
83 views

Single supply 5V low noise hydrophone preamplifier [closed]

The title speaks for itself, I want to know if there is some circuit that provides low-noise, single supply operating at 5V and high gain to be used as a hydrophone preamplifier. The output of the ...
0
votes
2answers
76 views

What's a loop current?

I just started mesh analysis, but don't really understand the concept of a loop current. The current in different parts of a loop is not necessarily constant - two parts of the same loop can have ...
2
votes
1answer
51 views

Circuit analysis?

So far I've learned these circuit analysis techniques for: Tellegen's Theorem Using only KCL Using only KVL Solving a system of equations that consist of all KCL equations and all KVL equations ...
0
votes
4answers
115 views

Circuit capacitance question

Given the following circuit, what ways there are to calculate its total capacitance? Thing is this is not a simple case, and I can't really decide which part is parallel and which is a series, ...
0
votes
4answers
86 views

Current and voltage sources?

simulate this circuit – Schematic created using CircuitLab From what I understand, the magnitude and direction from an independent current source is constant. What would happen in the ...
5
votes
1answer
576 views

How can circuits always be solved?

I've just started circuit analysis. All the examples, I've seen so far involve using using KCL/KVL or nodal analysis. They all consist of setting up a system of equations and solving them which gives ...
2
votes
3answers
192 views

Input resistance of a transistor circuit

I have a question from the razavi's microelectronics book: I'm puzzled because in the solution provided, the first line states that: "We know that the input resistance Rin = R1||R2||\$r_π\$." ...
1
vote
2answers
76 views

Why are resistance matrices always symmetric?

My book says when using nodal analysis to find the voltages and currents in resistive circuits, the resulting matrix (of the system of equations) is always symmetrical. Why? The exact quote is: ...
0
votes
1answer
39 views

How I find the current and voltage in this matrix?

My book above uses nodal analysis to find the current and voltage across the resistors. Now consider this alternate circuit: Look at the branch that doesn't any components (the second straight ...
-1
votes
1answer
111 views

Generate -10V to 2V from 12V to 0V

I am generating square pulse 3.3V to 0V from FPGA and through a level shifter (12V to 0V). output we require is -10V to 2V. Any suggestion? We are wondering to use comparator now or is there any ...
1
vote
1answer
60 views

Energy harvesting circuit modification

I'm currently doing a project on micro-power harvesting and I wanted to make some practical application but need to modify a circuit I've found. I'm not really sure about all the calculations, so I'd ...
5
votes
4answers
422 views

Kirchhoff's Laws and Circuits?

I just started circuit analysis today and learn't about Kirchhoff's Laws. Its pretty straightforward, but in all the examples my book gives they already specify the direction of the current and the ...
2
votes
2answers
94 views

Why are some terminal blocks blue and grey in color

Looking at some terminal blocks like the one below, why are the top level positions color coded blue while the middle ones are in grey? I understand yellow-green are for ground connections. I am ...
0
votes
1answer
81 views

Choosing Screw Terminals for connecting Arduino to other components

For connecting a 16 channel relay board to 16 devices running off 24VDC, and for connecting the relay board to Arduino, I am thinking of using screw terminals where one side of the terminals connect ...
2
votes
2answers
53 views

Create a fake depth encoder signal on a surface system?

I am trying to create a test box which will do away with the actual depth encoder as it is awkward to have out all the time the encoder is similar to this: ...
0
votes
0answers
43 views

Thevenin equivalent circuit of a non-linear driver circuit

If I am using a non linear circuit to drive a linear circuit, how do I analyze the driver? Is there a way to find the Thevenin's equivalent circuit? For example if I look at the full wave ...