# circuit analysis

1. ### Simple Timer Circuit - Will this circuit work?

Hi Guys, So I've been trying to wire up a simple timer circuit on a breadboard. I'm a complete novice so I'm just following youtube Tutorials. I found this one video which shows how to do it but It's a little over simplified so I had to fill in a lot of the gaps which may be a source of...
2. ### Circuit review/analysis for a stepper motor auto-enabling and time-delay mechanism.

Hi people :) I would love some help reviewing my little circuit.. I have a stepper motor driver (TB6600) which has an "ENABLE" function. It has an ENA- that is supposed to be connected to the ground, and a ENA+ where you supply the signal for ENABLING or DISABLING the stepper motor connected...
3. ### Will this simple Piezo circuit work?

Hi guys, Just wondering if this simple circuit will work as I expect it to. So this is for an engine, I'm utilizing multiple Piezo igniters to create a spark plug and I'm trying to figure out if this will work. I understand that this would be pretty easy to test I just don't have the...
4. ### I can't understand how to translate this into math: potentiometer as voltage divider.

Teacher gave us this circuit to analyze and we're supposed to use the voltage divider formulation: $V_{R1} = \frac{E\cdot R1}{R1+R2+R3}$ It gives me: $V_{R1} = 4.55$ $V_{R1} = 6.69$ $V_{R1} = 3.75$ The problem is, either I don't know how to interpret these numbers, or I'm not...
5. ### Thevenin's theorem BJT derivation

Here, I want to use Thevenin with those 2 resistors in the base. How can I combine those two resistors with thevenin or do you have any other better idea to combine them? (circled with red in the picture) (PS: I don't ask the solution of the question. I'm only asking individually the...
6. ### Help with this dc offset circuit

Qualcuno può aiutarmi con una spiegazione della funzione di questo circuito. Translated; Can anyone help me with an explanation of the function of this circuit I can't find any article on the web
7. ### Shocked by beginner circuit kit

I was trying to visualize a beginner circuit problem on my breadboard and I plugged in my circuit, touched a resistor and got a nasty shock. I am a cs student playing with circuits to build some logic gates so I really am a complete beginner. Why did this happen? How can I prevent this from...
8. ### How Can I measure MOSFET ro(output resistance), ID(DC current) at LTSpice?

Viewed 1 time 0 The subject is to make ro=500k, ID=100u by setting VG3,VG4 and W/L of MOSFET. And I got the exact values from Hand-calculation, and am trying to test it by using LTSpice. I did make this schematic. and DC currents of two mosfet was around 74uA (I don't know it is right way to...
9. ### I'm getting different results with the LTspice simulation

Hi, There was an example from my book and I wanted to build the same circuit on LTspice to test the results. However, when I create to simulate the circuit in the LTSpice environment you see below with the different outcome values. and here my ltspice results: I could not find the same voltage...
10. ### Which University affored affordable single course for non-student ?

I was looking for affordable course in electrical engineering that as overall and particularly in Analog, digital circuit and HF. I did find a very good one from Standford University but it is too expensive. has anyone get into single course from his choice in University where the prices are not...
11. ### The relation between Vin and Vout (diodes circuit)

Hi, can anyone here tell me if the function I found that relates the Vin to Vout is right? So I made a mesh analysis to find the current in the first mesh (left to right) and in the second and finally got that the Vout = (2/11)*Vi +6.328 (is it right?) threshold voltage = 0.7V
12. ### Why the voltage is positive while the current is decreasing

Hi all, The question is: The solution is: The formula used is: Why did he change the formula by putting an additional negative sign in front of the formula? Why does the voltage increase as the current decrease? The question and answer are from: FE Exam Review: Electrical and Computer...
13. ### Problem about Summing Amplifier on LTSPICE

Hi, I'm studying about summing amplifiers and try to make a proper circuit via on ltspice You can find my .asc file and the screenshot of my graph. My problem is I'm having trouble with trying getting a proper sin wave from Vout... I'm getting proper sin waves for inputs of V1 and V2 but Vout...
14. ### Samsung Washing machine won't power ondc41-00189a

Hi there, I have samsung eco bubble washing machine. I was using multimeter probes to test voltage and the probe slipped and it seems something was shorted. Now the machine won't power on. PCB dc41-00189a I'm a Newbie Please help me to troubleshoot this pcb.
15. ### I want to study about "Capacitance" on the graph calculations. Please suggest me source for it

I wanna study about calculating the capacitance value using the graph Where can I study about it and here is the example graph for this

I have solved my question like that successfully with mesh analysis which the question wanted from me. But I am just curious that how can I calculate this circuit using nodal analysis? Here is my calculation: and here is the question of the circuit: I don't want the whole solution. I...
17. ### I'm stuck at couple points in the problem

I realy tried this question but still I am out of the answer. Please and please can you solve it?
18. ### Mesh current equations yielding 2 different values for i2 current.

My mesh current equations: - 300*i1 + 500(i1 - i2) + 600*i1 = 0 - 200*i2 -25 + 13 + 500(i2 - i1) = 0 Since i1 is 25mA i2 can be found easily. However, equation 1 will yield 70mA while equation 2 will give 35mA for i2. What am I missing here? I would be very grateful if someone can point out...
19. ### Can I add 120V lines to the schematic as shown without frying anything?

This is an electrical question, but I want to explain the application first: I have an LED fireplace that I'm putting in to replace a wall heater. I wired it to run through the wall thermostat, but when the thermostat turns the fireplace on it just turns on the lights, then you have to manually...
20. ### Multiple-input controlled sources and Tuinenga SPICE book pg27

https://www.pspice.com/multiple-input-controlled-sources-and-tuinenga-spice-book-pg27 (briefly how is he getting k8.v2.v3 in the images) He's trying to use POLY(dimension) to model a source using a polynomial to represent it. Form of Poly is k0 + k1x + k2x^2 and so forth so.. how the heck has...