Questions tagged [negative-voltage]
The negative-voltage tag has no usage guidance.
138
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µA723 output Zener diode: why is it as high as 6.2 V?
The µA723 voltage regulator has a 6.2 V Zener diode on its output. I am trying to understand why the Zener voltage is as high as 6.2 V. (LM723 or LM723C are more or less equivalent parts, raising ...
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6
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How come negative power supply has negative voltage only
So I have seen power supplies that produce e.g. -48V DC (used e.g. in telecom but probably not only). For sure, that power supply is floating and in no way is negative terminal connected to earth. So, ...
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LT1054 wrong output
I'm using a LT1054 to generate a negative voltage to power my OpAmp's. I used the circuit described in figure TA03 of the datasheet. My Vin is 15 V and my R1 and R2 are 20k and 220k respectively. With ...
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Summing Amplifier Supply Voltage
Consider the case that I have a standard inverting summing amplifier with two inputs: 0.5V DC and 1V DC. Therefore, the output of the amplifier should be -1.5V related to GND. However, If I connect ...
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How to obtain negative voltage for op-amp?
How to setup negative -10 V for an op-amp to be designed on a PCB? I read that -10 V can be obtained from a power supply by connecting positive to ground and negative of the supply to the node where ...
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136
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Using a DCDC buck converter for negative supply
I am still fairly new to DC/DC converters and was wondering how to generate negative output supply with a positive input supply. I don't know what the general requirements and limitations are but here'...
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1
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661
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Op-amp dual supply methods
To power an op-amp with a dual supply (+Vcc and -Vcc) you can use two power supplies connected in series.
I would like to find an alternative and less expensive way to do this as (in my project) the ...
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Creating -5V supply from a AC/DC adapter
I want to use a Friwo FOX12-XM 5.9V adapter from RS with a -5V LDO to create a -5V supply which I draw as follows:
Would this be fine and is the adapter isolated?
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What is the most used bi-polar output SMPS topology in gate driver isolation?
I have some questions concerning this schematic:
What is the topology used here? I am guessing flyback without feedback circuitry.
Why is the TPS40211 utilized here? Is it to provide more current? ...
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How to generate -5 V from +5 V and GND?
I have an Arduino providing +5 V and GND. I have a component that requires +5 V, common GND, and -5 V connections. Is it possible to generate -5 V? If not, what input voltage do I need?
I am driving a ...
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Is it possible to use one voltage source for an op-amp?
This is a typical to op-amp for a non-inverting amplifier.
I have tried to google this before I asked this question.
Unfortunately, all circuit diagrams seem to require two voltage sources. In real ...
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±50 V from two 50 V DC-DC boost converters
I am having trouble building a power supply for my car audio amplifier board.
The board needs a ±50 V, 250 W RMS PSU, which is why I bought two switch-mode power supplies, each 50 V, to connect them ...
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How can I supply −5 V to an op-amp?
This is the circuit that I intend to implement on a breadboard.
I only have an ESP32 microcontroller, so I can supply the +5 V, but I have no idea how to supply the −5 V.
If I change Vee to 0 V (GND ...
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Biasing a low AC voltage for input to an ADS1115 ADC
I have an AC signal from a position sensor that changes between -200 mV and 200 mV, something like 400mV peak-to-peak.
I have ordered an ADS1115 breadboard and I use an STM32 microcontroller.
I'm not ...
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1
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Use GND as V- in voltage regulator
For a circuit sensor, I need +15 V/GND/-15 V. My supply voltage is a single +5 V rail from a standard switching PSU. I looked at different voltage regulators and found, besides others, the ITA series ...
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Negative voltage from a positive LDO
I came across this design which generates +1.5V and 1.5V from https://simple-circuit.com/arduino-ac-current-measurement-current-transformer/)
My question is: with the same DC/DC isolated transformer, ...
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136
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Using 12V output as ground in 24V power supply to form +/-12V rails
I have a power supply which outputs both +12V and +24V, Here's a photo:
Can I use the +12V as ground in my circuit to have a -12V(from 0V)/+12V(from 24V) output?
The load on the -12V output will be ~...
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Positive and negative voltage level shifter + inverter
I am looking for a level shifter/inverter that not only changes the high-state to another voltage but also generates a negative low-state voltage. The output of Inverter 1 is fixed to (0V … 600 mV), ...
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278
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How to get negative voltage on PWM signal
I'm researching EV charging stations. Looking at the SAE J1772 communication protocol, I see that there is a +12 to -12 volt 1 kHz PWM signal on the control pilot, which indicates the charging station'...
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Using negative supply rail instead of ground in SMPS IC
I'm working on a solar power inverter I noticed that all PWM ICs using negative 12 rail as a gnd...
As an example a PWM IC SG3524 which is used to convert batteries voltage to high dc bus voltage used ...
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1
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141
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low voltage cutoff for negative voltages
I've been trying to design a simple low voltage cut-off circuit for my dual supply +-9V circuit. The positive side works as intended with the LM431 and a PMOS, but the negative side not so much.
The ...
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Positive and negative voltage readings across a rig simulating bearing contact, supplied with a DC source
I recently ran a few experiments to simulate the effects of shaft voltages on motor bearings through using a simplified experimental rig. The rig simulates bearing contact. I applied a DC source ...
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Powering nixie tube from negative voltage?
I've built a photomultiplier tube supply; it takes +100VDC from a boost converter, which then goes through an inverting (in the sense of postive->negative rather than DC->AC) charge pump to give ...
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128
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Using NMOSFET for driving negative voltage
I want to use NMOSFEts for driving negative voltage. Is it possible to use it?
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Philips PE1535 bench power supply - reason for design choice?
Just a little question about the Philips power supply PE1535.
Link to original manual :
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Philips/PE1535%20-%20PE1545.pdf
Why the negative power supply ...
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0
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181
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How to safely read +-5V with an Arduino
I have a -5V +5V binary signal coming from a CNC controller that I want to read with an Arduino.
This is the way I have it setup:
The resistors are actually 10K. The left voltage source would be the ...
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188
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Does the negative voltage regulator emit noise into ground
I am designing an inverting voltage regulator using a LT3758 controller to generate -15 V from a 12 V / 5 V input. This is a non-isolated regulator.
My biggest concern implementing the design is if ...
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291
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Contrast voltage for display from PWM with negative rail
I want to control the contrast of this display using a well-filtered PWM output.
They recommend a potentiometer between Vdd and Vee (negative built-in rail):
With my MCU I can generate a filtered PWM ...
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If you source a negative voltage from a power supply, should the current be negative also?
I am clear that negative currents are simply currents that flow in the opposite direction. I am unsure as to how to apply this information to the real world. (relating to positive and negative leads)
...
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2
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DC to DC converter connection [closed]
I am fairly new to electronics and I started to have some doubts. I am going to use a DC to DC converter R1SE-0505/H2-R (5V to 5V) to have an isolated power supply for the audio components. I have ...
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196
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Negative voltage value for AD620 amplifier
I am using AD620 to amplify the signal of a pressure sensor, and a negative supply voltage must be added to V- pin. should the negative voltage value be the same as the positive supply voltage? or any ...
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2
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68
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OP2177 opamp with single supply
Does anyone know if I can use "OP2177" with a single supply without a negative voltage on V- ?
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Is it OK to create a negative rail just by dividing voltage with resistors?
I want to build some circuits to learn about op-amps, and so I would like to set up a negative rail.
Are there any problems in creating a negative rail by using an 18 V bench supply and then simply ...
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338
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Improve the response of this circuit
I designed this circuit (shown below) to level shift an input PWM (10 kHz 5% duty) signal (from microcontroller, 0/+3V3) to 0 and -12V. When the input PWM is HIGH (+3V3) the output is at 0V while when ...
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PWM level shift
I have a 10 kHz PWM (0V (LOW) to 3V3 (HIGH)) which I wish to level shift as following; when PWM is high (3V3) the output should be 0V while when PWM is low (0V) the output should be -12V. Ideally this ...
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How to get negative voltage?
There's a bunch of posts about this, but they're all for very specific scenarios. I'm a newbit, and some components, like op amps, require both a positive, and negative voltage.
But how do you get ...
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Trying to understand negative voltage generation with capacitors and diodes
I want to generate a negative voltage from a possitive rail. To do so, I'm reading this article. Here is the schematics it is depicting, assument the input step is +10V:
I understand that when the ...
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141
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Vestax PMC-07 Mixer PSU
I'm trying to fix a Vestax PMC-07 Mixer and I'm puzzled by the schematics.
It is fed by a single +12V wall-wart switching adapter through a DC Jack.
Can this configuration really produce a negative ...
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How can i generate a negative potential/current and alternate the pin-input between positive and negative potential/current using an arduino uno?
My goal is to make the barmagnet rotate by activating two coils and use both forces at the same time with an Arduino Uno. One coil should have a positive potential or current to attract the negative ...
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Virtual ground concept in electronic circuit
This is my current sense circuit that I connect to Arduino in order to measure how much current a load draws.
As you can see at the bottom of the image there is a -5 V voltage source connected to the ...
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Is there any way to have a diode that have very small resistance from reverse path?
I'm trying to find a way so I will always have close to 0V at the measurement point (above the diode), when I have 0V as input. ...
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117
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How to adjust/vary a negative voltage
I'm in the process of building a bench top power supply, based on an ATX PSU.
I have nearly finished the build and have a unit which can supply +3.3 V, +5 V, +12 V and a variable voltage between +0.8 ...
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What is the problem with connecting a negative voltage to an op amp's negative lead while the possitive one is grounded?
I'm reading a manual on op. amps that presents the following schematics:
And says:
[Context: Vin goes from -0.1V to -1V]
When Vcc is powered down while there is a negative voltage on the input ...
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1
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662
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Discrete negative voltage regulator oscillating under load
I'm trying to save a few volts voltage drop and use a discrete voltage regulator, having a feedback doesn't really matter because the current draw is very low.
In the diagram below, if I remove C2 ...
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Using a switch detect IC with negative voltage
I am designing a circuit where a negative voltage signal can have multiple levels, eg -12, -8, -6 depending on the circuit state.
I am looking at several switch detect ICs such as TI's TIC12400 that ...
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How do you calculate negative and postive voltages in a grounded circuit?
This may be a vintage question, I'm not sure. I am self-studying electronics using some old books and came upon the problem below from "Basic Electronics" by RCA Institutes, 1965. The book ...
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How does this -ve power supply work?
This data sheet (linked from the product page of Rapid p/n 61-6211) covers an adapter for LVDS displays, that can provide various different voltages. This includes a 'VGL' signal that is set at -6.8V.
...
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Pulling down positive voltage to limit negative voltage current
Below circuit is the negative rail of a dual tracking power supply.
How do I detect voltage drop on Node1 and pull down Node2 to limit the current without using an op-amp?
Edit: I just want to define ...
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195
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Problem with a tracking LM337 stability
I'm building a dual rail tracking power supply, for the negative supply because the current is not going to exceed ~200 mA I decided to use LM337 both for simplicity and stability of the circuit (so I ...
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4BIT DAC has negative voltage at op amp output
My school task was to simulate a 4BIT DAC converter in multisim. Im supposed to simulate the circuit when the switches are on/off and measure the output on the op amp.
I think the circuit works fine ...
