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-1
votes
1answer
56 views

Which Clock Would Run Faster [closed]

I have two identical clocks: one is plugged into 120 VAC @ 60 Hz. The other is running on a 12 volt battery. Which would run faster, and more importantly, WHY? Based on my understanding of a quartz ...
0
votes
2answers
34 views

Short the circuit of a voltage controlled voltage source when finding out the v(t) for \$t>0\$

Question Find v(t) for t<0 and t>0 in the circuit below. Solution My Question Why we can see the voltage controlled voltage source as a shorted circuit when finding the v(t) for ...
0
votes
1answer
32 views

Current of a circuit with regulator

When the specification of a regulator says that output is 1A for example the whole current of the circuit will be 1A? For example I have a regulator in series with a 100Ω resistor and a 7V source.The ...
2
votes
1answer
84 views

Operational amplifier circuit with one ac and one dc voltage source

The following circuit contains ideal operational amplifier, Vs voltage is sinusoidal with amplitude of 1Volt and frequency of 1kHz, where VE is a dc voltage of 2Volts. I am trying to use ...
3
votes
2answers
254 views

0 to 2A variable current source circuit

I'm trying to build a 0 to 2A variable current source following the Linear app note. Here's the schematic: The circuit is a difference amplifier (LT1995) providing gain to the voltage developed ...
1
vote
1answer
492 views

Connecting Switches to Hidden Supply Pins in Proteus ISIS

I am currently working on a simple circuit involving logic gates in Proteus ISIS from Labcenter. By default, the power pins are hidden. You can access them by right-clicking the component, selecting ...
2
votes
1answer
173 views

Maximum current, maximum voltage

Given that 0 <= R <= ∞ in the circuit shown, consider these two observations: Observation 1: When \$R = 2\Omega\$ then \$v_R = 4V\$ and \$i_R = 2A\$. Observation 2: When \$R = ...
0
votes
0answers
23 views

CFL and CCFL difference: Can I use CFL balast like CCFL inverter?

I want to ask where is the difference in CFL (compact fluorescent lamp) and CCFL (cold cathode fluorescent light) in the meaning of thier elctrical circuit. I know it's two different types of ...
-1
votes
2answers
94 views

Connecting a 10V variable source across a load (without ground) [closed]

I have a problem. I am a second year Electrical Engineering student. But the problem I experienced is from first level electronics (for which I could not find a solution). I have been recently ...
1
vote
2answers
118 views

0-12V Adjustable Home Made DC Source not working [closed]

I have a home made dc source that is made a few years ago. Solders at the back of the board are very bad so I can not track the connections very good. But it's circuit diagram is very similar to the ...
0
votes
1answer
56 views

Expressing the current through a dependent voltage source

Consider the circuit below: The task is to find the node voltages V1, V2 and V3 (labelled 1, 2 and 3 above). In order to solve the problem I apply the node voltage method; summing all the currents ...
0
votes
0answers
50 views

Calculating currents with a current source in series

Is this circuit correct? I am not sure if I can consider I5 as a current source. I remember that current sources cannot be in series. Or is this as easy as it looks. Specifically I am getting ...
0
votes
2answers
66 views

Current and voltage sources

What happens when a current source is connected in series with a voltage source? I mean to ask, what will the current be through the series combination and voltage across it? Is it allowed to make ...
4
votes
2answers
432 views

Logic gate using current source and diodes

This circuit is supposed to work as a logic gate. I need to find out the logic operation it performs. Suppose the diodes are ideal. https://www.circuitlab.com/circuit/egg3wh/logicgate/ ...
0
votes
1answer
189 views

Low voltage/current power supply for wide range of inputs

I was thinking of simple low voltage/current power supply that can accept wide range of input voltages, up to the hundreds. Let's say, the input is 20 to 160V DC and output has to be 10V with 20ma ...
2
votes
1answer
258 views

current controlled current source

Objective I am trying to build a gain-of-1 current controlled current source (current mirror) that is less sensitive to resistor value variation. The designs i have been making are highly resister ...
4
votes
2answers
644 views

Driving Relay Board with Shift Register (Shift vs Sink)

I am trying to drive some ebay bought 8 channel relay boards. They are pretty simple, have a launchpad or arduino toggle a pin and the board turns on. However, I need to use a shift register with ...
0
votes
3answers
417 views

Use transistor to auto swap power source

Basically I'm looking to use a simple transistor circuit to diconnect one V+ (or ground) when another is connected and automatically switch back when the switching source is removed. Like having a ...
5
votes
3answers
529 views

Purpose of these two transistors

Hi does anybody know what's the purpose of the Q1 and Q2 transistors, sounds to me like they are constant current sources. Am I wrong? Could somebody explain me the purpose of those Q1 and Q2 ...
2
votes
1answer
322 views

Converting a battery powered pocket heater into a portable 5V power source

I bought the attached pocket heater. The elevated element seems to be heater spirals so the red cables seem to lead to short circuit - capable circuitry. Background: So I built this tight case for ...
5
votes
3answers
271 views

Capacitor discharge and 1/2 terminal voltage sources

I understand that this is really basics of electronics, but I would really appreciate if somebody clearly explained following question. So here is a small set of questions related to similar topic: ...
4
votes
1answer
245 views

Understanding a transistor configuration

I started watching this video series on a DIY lab power supply by Dave @ EEVBlog. On his video he's analyzing mostly simple constant current circuit. However, at the top of the circuit there's two ...
1
vote
2answers
487 views

Current source with pulse option

I am seeking a very fast (10nsec rise time) transistor based fixed current source that I can use with my CPU. The CPU will use the GPIO to turn on or off the current source. This will be used to ...