Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [dual]

77 questions
19
votes
2 answers

What is the dual of a diode?

A diode has an exponential I-V curve. To a first approximation, it will pass whatever amount of current is required to keep the voltage across it constant. Is there a passive component that will (approximately) drop any amount of voltage to maintain…
user253751
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Building a dual-rail, regulated DC power supply: 1 diode bridge & center-tapped secondaries, or 2 diode bridges and separate secondaries?

I'm looking to build a dual-rail, regulated, 18VDC power supply based on the 78xx and 79xx regulators. The circuit is inspired by AMB Audio's sigma25 (amb.org/audio/sigma25/) and sigma26 (amb.org/audio/sigma26/) regulated power supplies. I have also…
dhaninugraha
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6
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3 answers

dual potentiometer wired in parallel

I'm trying to understand if those two circuits are 100% equivalent. I mean, if I use a dual gang 100K linear potentiometer, and wire it like VR1A-VR1B, do I get a single potentiometer exactly like VR2 (50K linear)? is the same true with the presence…
Dimitri Petrucci
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5
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3 answers

Switching between two power sources

I am designing a circuit, which can use either 5V from USB, or some higher voltage (7-12V) from a battery. If both power sources are connected at the same time, I want some kind of electrical switch, that would disconnect the battery and power the…
Dan
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4
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2 answers

Why are capacitors used when obtaining dual power supply from a single power supply and how to know the values?

What happens if we only use 2 resistors in the figure. Why do we use capacitor if we have a DC source already? And whats the easy way to calculate capacitor capacitance for given R and Vin?
user16307
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2 answers

Complementary Transistor Pair

I am wondering, why is there no complementary transistor pairs to buy, since their use as individual devices is pretty common in audio amplifier applications. So for complementary transistor pair it is desired to have as identical properties as…
Keno
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Dual Supply from single 24v dc source and 12v regulator

I was thinking about different ways a dual supply could be created, and I was wondering if something along the lines of what I made in this schematic would work. I don't have any kind of formal education in this stuff so excuse me if there is some…
Ella Robinson
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Can Dual BJT packages be reliably used as Current Mirrors

Say I need current mirrors, can I just use Dual NPN packages? I know that if multiple BJTs are manufactured in a die, they can pretty much be guaranteed to have the same spread. Or, should I just stay away from them and just go with those that are…
Majin_Boo
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What should I do with the unused diode in the SOT-323-3 (SC-70-3) package?

I'm planning to use one of this diode in my circuit. But the package contains two of them. I chose it mainly because of its 3ns reverse recovery time. How do I use them in my circuit? I have three options in my mind if you won't suggest a forth…
hkBattousai
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Measure dual voltage with single power

I have to build an MCU system that has to measure a dual voltage, V+ and V-. The problem is that my system needs to be powered with a single power supply. To measure the V+ input, no problem, I simply make a resistive divider and an op amp as a…
Federico Massimi
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3 answers

How to power one fan with two different power supplies individually

I have two systems that run on separate power supplies and turn on independently of each other.The issue here is that each system needs to be cooled by the same cooling fan. So I need to know if there is a way that I could have either system on and…
user147980
2
votes
3 answers

Connecting two op amp circuits each of which use dual supplies, but where the two supply voltages differ

One of the op amps uses +- 12 volts and the other +- 5 volts. With only one circuit, I understand that the common ground for the entire circuit is midway between the two supply voltages, but when the second circuit is present, I do not understand…
Zweite Bear
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2 answers

Common ground with 2 transformers

Beginner question so please go easy on me. My question is around what is the correct way to have a common ground reference on a circuit at that 2 different voltage sources. the below schematic is a simplified version of the problem. The device I am…
rducky
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Power supply with three pins on the output, why?

I opened up the power supply to a HP printer and I see that the output has three pins. I measured voltage on one pin to ground and it shows 8.3V. The adapter says: Output 24V @ 1A. Is this a dual rail power supply? Why don't I don't see 24V on the…
Grepsoft
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What are limitations of Millers theorem for amplifier?

I mean to say that are the two circuits one original and other its miller/ drawn exactly equal in all respects or their are some difference in some respect if so please mention. I am not able to think about any other parameters except current hain…
SUNITA GUPTA
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