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1
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0answers
29 views

Binary Encoder Circuit

How exactly would I go from 7 output lines to 127 outputs. Since you can encoder a value of 127 with 7 lines I would imagine this should be possible.
0
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0answers
22 views

How to set up the read part in Ram from Logisim?

I really need help for the read part in this project! Basically, we should build up a 4 nibbles Ram with 4 bits data register, 2 bits address register and 1 bit mode register. The problem is my ...
2
votes
2answers
90 views

Lithium Battery Charger IC - Charging and Power

Basically, for the circuit I'm making, I need it to be powered by a Lithium battery. Also, this Lithium battery has to be able to be charged via USB. I have seen external chargers for doing so, ...
0
votes
0answers
24 views

Multi Circuit Button [on hold]

I'm a complete beginner in terms to electric circuiting. I'm trying to add a additional audio circuit to a toy but still use the buttons and circuit already there. Before I try I just want to ask, can ...
0
votes
1answer
33 views

Pump control system without arduino

So i saw this schematics i pretty much understood it all, the comparetors, the sensors, the variable resistors , but because i am a beginner i still dont understand some things. 1- why did he use a ...
0
votes
2answers
69 views

Odd results solving this very simple first-order RC circuit

Here's the circuit: I'm trying to find the differential equation for the current through the capacitor (i_c(t)). Using KCL at the top node, I know that ...
4
votes
8answers
705 views

When does the placement of a resistor matter?

I've been a programmer for years but am very new to electronic engineering. So far I see people saying it doesn't matter where a resistor goes in your LED circuit as long as it is present, but it ...
0
votes
1answer
50 views

Reciprocal Resistances of a 2-port

I was trying to calculate both symmetrical and reciprocal resistances of this circuit: I managed to solve the symmetrical resistances: $$R_{11}=9.09 \Omega \\ R_{22}=4.09\Omega$$ But I can't ...
0
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0answers
27 views

Nodal analysis phasors question?

In the figure, 1H and \$4\Omega\$ are in parallel and are equal to \$(2+j)/4j\$ \$6\sin(2t) = -6j\$ \$1/6\$ F \$= -3j\$ So in the node \$V_1\$ we have $$-6j=\frac{V_1}{-3j} + \frac{(V_1-V) ...
-3
votes
1answer
52 views

mosfet driver buffer with jfet [closed]

i want to drive 10 irfp460 mosfet that parallel and use ir2110 to drive them.but ir2110 cant.can i use bjt totem pole or i Must use jfet totem pole to drive mosfet? the Threshold Voltage of irfp460 ...
0
votes
2answers
67 views

Automatic 12V plant watering system?

I'm planning to make a plant watering system . There is a beeper so it will alert us when the soil is dry.I have got a 12V DC motor . So i'll be removing this beeper and i need to add this DC ...
-1
votes
0answers
37 views

Powering high power LEDs [closed]

I want to power some high powered LED (R2) with this circuit. I would like the LED to be on for about 1 minute and they discharge C1 via R2. When C1 charges SW1 is open and the LEDs are off. When ...
0
votes
0answers
60 views

Controlling the luminosity (flickering) of 2 sets of 12V (in-parallel) lamps connected to external power source, via a PWM pin

I have been playing the last few days with the Arduino mic, and must say it does open a fascinating world. One very basic project I have been doing, with the help of various online tutorials, is to ...
0
votes
2answers
81 views

What is the name of a circuit that delays powering of another circuit?

I'm having trouble figuring out the name of this circuit. It needs to delay turning "on" a 12V circuit and a 120VAC circuit, after a 5V circuit has been turned on. Example: Turn on 1x power ...
0
votes
1answer
32 views

Programmable Unijunction Transistor Circuit

I am currently teaching my self electronics and have a question about PUTs. I am wondering why there has to a resistor on both sides of the PUT in this circuit: Please note that I have already read ...
0
votes
1answer
62 views

How to Simply Lower Current in Circuit and Maintaining Voltage?

A charger with a transformer is putting out 12.6V and runs at 5A when I plug in the battery as the bat is fairly empty (10V of 12). I would like to limit the current to 2A. I tried a 5ohm 5 watt ...
0
votes
1answer
36 views

Assigning current direction in mesh analysis

Below is a circuit schematic of sources and resistors. $$V_S=10V, R_1=50Ω, R_2=15Ω, R_3=5Ω, I_S=2A$$ Question 1: Calculate the current i1 in amps that goes through R3 from left to ...
0
votes
1answer
63 views

high speed optocoupler circuit

I have 4n35 optocouplers, I am using these to isolate a motor driver circuit and the Arduino controlling it. I put one on the slave select pin and one on the tx line to the motor controller (there is ...
2
votes
2answers
226 views

Is this 12 volt LED circuit correct?

I found this "Plant Grow LED light" circuit on the Internet and I wanted to know if: (Please don't feel pressured to answer all my questions. You can just answer a few only if you like.) this is ...
1
vote
1answer
99 views

Minimal circuit for ARM STM32F411

I'm trying to determine what a "minimal" circuit is to get an STM32F411 processor running and able to blink an LED. I wish to use the internal PLL and no external crystal at this point. I've looked ...
-3
votes
2answers
87 views

How to Design a schematic for 8-LED Logic Circuit and Turn them on in pairs? [on hold]

I'm trying to design the schematic of an 8-LED logic circuit and turn them on in pairs according to the following sequence: 1 - 8, 2 - 7, 3 - 6, 4 - 5, 5 - 4, 6 - 3, 7 - 2, 8 - 1 ,i used ...
2
votes
1answer
202 views

Amount of heat developed in capacitors

simulate this circuit – Schematic created using CircuitLab Q10 is equal to 10μC. No charge on C2. I need to find the amount of electric work that is converted into heat, from the moment ...
0
votes
1answer
43 views

Binary Counter IC Counting Incorrectly

I'm currently trying to use 74HC163 in a project, and it appears I have it wired up correctly, but it counts in a very strange sequence. I wrote down the sequence as follows: ...
0
votes
0answers
40 views

switching of mosfet using IC TL594

Switching of mosfet using IC TL594 I can't find the required circuit diagram switching of the MOSFET using an IC. Is it good to use the PWM method for switching ??
0
votes
0answers
38 views

Temperature Sensor Circuits problems (circuit and schematics pics included)

Just finished soldering this college project and tested for shorts with multimeter. All good in that region. The problem is the output at room temp is reading 3.5V ish which corresponds to over 40 ...
0
votes
3answers
83 views

Circuit Starving Question

I have a circuit where 2 DC motors are connected to 4 AA batteries and being controlled by an Arduino microcontroller. Whenever the motors start, they starve other components in the circuit and it is ...
0
votes
1answer
70 views

Simple digital circuit schematic question

Below you'll find the schematic for a circuit I have to build and analyze tomorrow for a lab. simulate this circuit – Schematic created using CircuitLab (Note that the blocks I've shown ...
0
votes
3answers
39 views

Powering on specific pieces of circuitry in sequence

I'm trying to power on specific pieces of circuitry in sequence, and have one piece active at a time. I thought a decade counter would be the way to go but most people seem to think a decade counter ...
1
vote
1answer
43 views

Motor speed control mosfet

I have a Raspberry Pi and I want it to control DC motor speed. I make the pi output 3x3,3V for controlling the speed. I need circuit that works like this; when one output gives 3,3V motor have 6V, ...
0
votes
6answers
162 views

How do you find the voltage across a capacitor at time t= 0 and t = infinity?

Here is a diagram of the circuit, I am confused about problems a and b. How do I go about solving these two problems? Thanks! By the way you don't have to tell me the answer, I just want to ...
-1
votes
2answers
84 views

Op amp circuit design

I am having trouble with understanding how to design circuits involving op amps. I need to design a circuit using as less op amps as possible which has the following characteristics: high input ...
2
votes
1answer
100 views

Correctly choose circuit decouplers and filters and schematics advice

I want to ask some help to correctly design a power supply circuitry with TPS799 voltage regulators. I've this reference circuitry: And nothing more explainations. I want to use same specifics of ...
0
votes
2answers
96 views

LC Oscillator, Tank Circuit

How does a tank circuit work with a dc power supply? I understand that if you charge a capacitor that's in parallel with an inductor and then remove the power supply then the capacitor and inductor ...
0
votes
3answers
100 views

Simplifying Series/ Parallel RC circuit

I was doing some exercises on transfer functions and ran into this RC Circuit. I thought that I was allowed to add up the two resistors since they are in series. Which makes that the voltage across ...
1
vote
2answers
90 views

Stuck in circuit analysis

I am having the following problems understanding the above circuit: -I understand the part where the opto-coupler activates transistor T3 acting as a relay driver. I also understand that this would ...
1
vote
1answer
56 views

Switch to power pump with relay [closed]

I couldn't find this question anywhere else. I have a pump, a 12v battery and a switch and can purchase any relays etc that may be required. I want it so that when a switch is triggered and kept on ...
2
votes
4answers
433 views

How to change the frequency of AC supply?

Im using an inverter to convert Dc into Ac from battery. I want to control the frequency of the alternating current ie., increase and decrease gradually (eg: 1Hz 2Hz 3Hz... 60 Hz). Is it possible to ...
0
votes
1answer
92 views

open collector digital output

I have a digital output board design which has 32 open collector (sinking) outputs which can be connected in parallel to drive a resistive load. The collector of each output transistor is connected to ...
0
votes
4answers
78 views

Why the output decreases in series?

I am just confused with below statement "A 100 W bulb is connected in series with a room heater. If now 100 W bulb is replaced by a 40 w bulb, the heater output will decrease !" if I follow this ...
0
votes
1answer
95 views

For what use is this circuit?

I need to power up an IC, but there is no description of reference design. Just an image. This is the image: This is a circuit to add to IC. But i can't understand it's use. Do it provide me a ...
0
votes
1answer
50 views

How to generate bar using decoder

Ic74154 decoder generate active low o/p i.e for example if input is binary 5 , 4 becomes low. I want a circuit which will give output when i/p is binary 5 then o/p is low for 0 to 4.It is possible by ...
0
votes
0answers
78 views

Light LED when 2 others are disconnected [migrated]

I need to make circuit in which orange LED will light only when yellow and red are disconnected. When one of buttons is pushed orange LED should turn off. See my attempt at it below. I am new to ...
0
votes
2answers
68 views

Can I feed lower than rated voltage?

I'm poking around on eBay for some capacitors to use in circuits which I'm working on and see that they have a rated voltage. After some quick research, I found that going over the rated voltage of a ...
2
votes
2answers
178 views

Transfer function of an op amp circuit

Let's suppose the following circuit: I am trying to find a relation between Vs, V1 and V2 at this circuit. Please note that Vs is measured in relation to the ground. I have declared some extra ...
0
votes
3answers
83 views

How to know if the generator is dissipating or generating power?

How do I determine whether current/voltage generator is generating or dissipating power. For voltage supply I'm quite sure it depends on current direction, if they are the same, then it's generating. ...
2
votes
1answer
89 views

Confused with mesh analysis

something about mesh analysis confuses me and I can't find an explainaton anywhere, as you can see on this picture (it's in French, but the schema and formulas should be enough to understand) They ...
-4
votes
1answer
41 views

how can i using CPU8085 and PIO8155 crate an alarm circuit and program [closed]

example ; we have smoke sensor, speaker and my circuit.When Sensor has been active, speaker to sing it. i'm newbie in this topic. how can i do it like this circuit ?
-2
votes
0answers
37 views

connecting two 3.7v battery's to tablet, in parallel for extend the working capa [migrated]

my tablet have 2500mah battery. it works for four hour. but I want to extend the source power. so I want to connect another same voltage battery to tablet. battery was 1500mah. can i make connection ...
0
votes
1answer
91 views

Resistance Wire Circuit Safety Around Water

I'm working on a project that requires heating of a copper pipe with water running through it. I'm aware that this is a common issue by itself but as there will be people working around the system ...
1
vote
0answers
47 views

Is lithium ion battery sutaible for all terrain vehicle

I have manufactured an all terrain vehicle.Is li-ion can sustain in the jerking of car,if battery is fully packed and waterproofed.If not,which battery should i use? Can i go for Li-polymer battery? ...