Questions tagged [dual]
The dual tag has no usage guidance.
80
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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 (...
7
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2
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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/...
6
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3
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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, ...
6
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3
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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 ...
5
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3
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Can dual BJT packages be reliably used as current mirrors?
If I need current mirrors, can I just use dual NPN packages? I know that if multiple BJTs are manufactured on one die, they can pretty much be guaranteed to have the same spread.
Should I just stay ...
4
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2
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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?
4
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2
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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 ...
4
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2
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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 ...
4
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0
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323
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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 ...
3
votes
1
answer
53
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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 ...
3
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3
answers
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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 ...
2
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1
answer
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Power supply with three pins on the output, why? [closed]
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 ...
2
votes
2
answers
818
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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 ...
2
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3
answers
518
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Supply current of negative rail
I'm using an LTC1983ES6-5 to provide a negative rail for both a MAX4311 and a MAX4395. LTC1983 provides up to 100 mA, but I cannot find in the other datasheets how much current is required for the ...
2
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3
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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 ...
2
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3
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Dual power supply with two boost converters
I currently have a dual power supply, that supplies +/-15V. One -output of the PS is connected to the other channel's +output (GND). Now, the problem is that I need +/-50V. I bought two step-up boost ...
2
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1
answer
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Design for a balanced (positive and negative) HV DC regulator
I'm trying to design a high voltage DC regulator for driving a PZT that will provide both +200 and -200 V outputs referenced to ground. The input is a rectified AC waveform that will provide UK mains ...
2
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1
answer
607
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Chassis Grounding a Bipolar Floating Power Supply
I'm building a simple function generator powered from a 24V AC wall adapter. I've rectified the incoming AC to 24V DC using a full wave bridge and an LM317. I intend to split the supply into +/-12V ...
2
votes
1
answer
481
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Voltage step up for bidirectional current source
I will be using a circuit similar to the following to create a bidirectional current source driving a max load resistance of 10k at a max of 2.5 mA. (based on this article http://www.ti.com/lit/ml/...
2
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2
answers
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How do I switch between primary battery and backup battery, if the primary battery drops below operating voltage or get disconnected?
I have low power system which requires dual batteries to overcome the loop holes in the current system. Currently I have two batteries: Primary Battery Li-Ion 3.7V 1800mAh and a secondary battery Li-...
2
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1
answer
689
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Virtual ground before or after low noise LDO?
I have two boards (microphone amplifier and speaker driver) that require +/-15 VDC. The max current required for the boards is 500 mA. Since low-noise dual power supply devices are hard to come by, I'...
2
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0
answers
554
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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 ...
2
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2
answers
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How to obtain a dual power supply ±2.5V from a battery for a portable system?
I’m working on a portable system that uses a microcontroller and an analog/digital converter. I want use this ADC in dual power supply mode so I need a ±2.5V .
In my previous project, the system was ...
2
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0
answers
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Is it practically possible to use mutually coupled capacitors as we use mutually coupled inductors? [duplicate]
Inductor and capacitor are dual to each other in Physics. One comes from Electric Field Theory while the other one comes from Magnetic Theory; the both theories expose strong duality with each other. ...
1
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3
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224
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What do these dual DC rating numbers on my Casio PB-2000C mean?
All devices I own except one have only one rating that matches what the PSU says, for example "12V ⎓ 2.5A" and that means if I have to get a replacement PSU it has to be 12V and at least 2....
1
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1
answer
1k
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Can I operate 2 electromagnetic locks using the same power supply?
I'm using this power supply:
Specs:
Input Voltage: AC90V-AC260V 50-60HZ
Output Voltage: DC12V
Momentary Current: 3A/5A
Persistent Current: 3.5A
To operate my ...
1
vote
2
answers
148
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Dual Slope integrator voltmeter improvement in Design
So, I'm attempting to design a dual-slope integrator voltmeter. I have the following block diagram so far.
Now an AVR microcontroller will have an ADC pin in the range of 0-5 Volts . So negative ...
1
vote
2
answers
324
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Dual Comparators connection that affect the design
If we use a dual in package comparator Example LM2903 and do use only one comparator, what should be done with the other one. It is sure that paralleling the two comparator will cause instability and ...
1
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3
answers
158
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How can I replace this 5565 SRAM with a dual port SRAM?
I have an existing device (an arcade CPU board) that stores some data in a 5565 64-Kbit SRAM. I want to replace it with a dual-port RAM so I can read the data with a microcontroller. I don't need to ...
1
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2
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How to switch between two DC power sources powering a motor on an electric vehicle?
Background: For a university final project, my student group is investigating the possiblility of powering a motorcycle with two seperate batteries, each of a different chemistry (Lead-acid and ...
1
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2
answers
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Why does the Dual Speed Dahlander motor need a bridge in the fast speed configuration?
On the nameplate of the motor is a Delta/Wye-Wye configuration, meaning you supply the ones (U1, V1, W1) and leave the twos open to achieve the slow speed. And for fast speed you supply the twos and ...
1
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2
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Coupled DC/DC-modules - correct input filtering
According to the support from TracoPower I use two THN-30WI modules (±15V) in conjunction as shown below (without each C1 and C2) to produce ±30V.
This works but I get a lot of noise.
The ...
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1
answer
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i want to duplicate a signal generator output
I want to duplicate signal generator output to dual. since i want to use same signal to two different place. Is this possible without amplifying and inverting the signals. Let me share some circuit.
...
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2
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Dual Power Supply (Two 9V)
I am Not Good At This, and I am trying to breadboard this circuit here:
http://www.instructables.com/id/DIY-EEG-and-ECG-Circuit/
But I am stuck on the power supply. The instructions state:
...
1
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2
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482
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Dual power supply circuit dropping voltage on applying load
I'm not an Electonics professional, and hope someone can explain why the circuit below, I've used to build a dual rail +15v,0v, -15v Power Supply drops voltage down to about -7.7 volts when connecting ...
1
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2
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Back feeding when connecting one side of circuit to differential op-amp
simulate this circuit – Schematic created using CircuitLab
I am building four 30v voltage sensing circuits to measure battery+/battery-, load+/load-, battery+/load- and battery-/load+ voltages ...
1
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2
answers
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On RS Latches (or Flip-Flops), NOR or NAND, via Duality Principle [closed]
Fig. 1 Duality Principle
simulate this circuit – Schematic created using CircuitLab
...
1
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2
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900
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2 dc-dc boost converters to create dual power supply
I'm doing a project with a Silicon Photo-multiplayer where the breakdown voltage when negatively biased is -25V. I was wondering is there anyway to connect two DC to DC boost converters to give me a ...
1
vote
1
answer
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Initial voltages of capacitors using mesh currents analysis
simulate this circuit – Schematic created using CircuitLab
The book I'm reading is noting that I should recognize the initial voltage across the \$C_1\$ capacitor is \$10 V\$ but I can't see ...
1
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2
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431
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Voltage not dropping in circuit
This schematic shows the circuit that I'm trying to build. At the moment I'm not using V2, as I'm having a problem with V1. From my understanding the diode should drop the voltage by about 0.7V, and ...
1
vote
0
answers
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Delta-Y transformation and dual circuits
I have been thinking about the relationship between delta-Y transforms and the dual of a given circuit and I am confused about a sort of overlap I see.
Take a delta circuit with resistances as shown, ...
1
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0
answers
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Addition of a voltage selector switch for a dual-voltage motor
I have a 3hp, single-phase 120V / 220 V, 1750rpm, 184t frame size, compressor-duty motor.
I would like to include a voltage selector switch in the junction box, to select 30A 120 V or 30 A 220 V ...
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0
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Dual fixture ( Stencil, SMT carrier...)
I have an output upgrade project on SMT, part of which is dual fixture (2 sides BOT & TOP on the same side).
So is there anyone here with experience with this? Can u give me some advice on this?
1
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1
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Circuit with dual power supply
Doing some reverse engineering to a PCB, I drew this part of the circuit. Looking into the datasheets, I found out the comparator (LMC6772) is able to drive the SCR (S6S2) by itself. But the designer ...
1
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0
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231
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Flyback diodes for motors wired in parallel
When driving two DC motors wired in parallel, do they each require their own flyback diode or can they share a single diode?
0
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1
answer
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Capacitor changing output voltage from 12v to 20v [duplicate]
I have a transformer with two output coils I have wired them together in series and used the connection between them as 0v and used the other two leads in a diode bridge rectifier. Without any filter ...
0
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3
answers
147
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I need a potentiometer to swing -/+ 5V
I need to have one "KNOB" that swings a dual power supply (+/- 5V) from balanced (+5 and -5) to 0v +5 or 0V and -5V and of course anywhere in-between.
My first thought is just the +5V ...
0
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1
answer
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What does dual DAC mode mean for this microcontroller board?
I have a STM32 development board with this manual, and regarding its two DACs somewhere in stm32f4xx_hal_dac.c file, the following is written:
...
0
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2
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146
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Replace lamp in old amplifier
I am trying to replace a fried lamp in my very old amplifier (a Dual CV 1280 Integrated). As I essentially only use the mode that is indicated by the fried lamp, I thought I could just switch it with ...
0
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2
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How can I use a dual 4-channel analog multiplexer independently?
I have a CD4529BCN Dual 4-Channel Analog Data Selector (datasheet).
Here is the truth table:
Here is the problem:
I have two sensors which are resistive. I want to read their voltage via a resistive-...