Questions tagged [undervoltage]
The undervoltage tag has no usage guidance.
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DW01 2s protection
I want to protect 2 18650 batteries with single DW01.
The problem is how to increase the protection voltage on DW01 .
I have read that I should use voltage divider on VCC pin. I just want to make sure ...
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Calculating an operational amplifier with changing power source
I've been stuck since days to calculate an operational amplifier circuit used as an under-voltage protection. At first my design:
simulate this circuit – Schematic created using CircuitLab
The ...
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Switching between 2 power supplies upon dropping below cutoff voltage efficiently
I am making a circuit which is powered by a lipo battery of 11.1V(3.7V*3). I need to check for the lipo's under-voltage so that the circuit automatically switches to a second lipo when the first one ...
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Low voltage supply to ups
Circumstances :
The power supply to our home is faulty and runs very low. Sometimes as low as 138V, most of the time 170V, but never 220V as it should. (We are in South Africa)
Sometimes the UPS ...
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Lead-Acid battery discharged to 5V - how much damage?
Something in my bike (USB Charger, Hella Socket itself) has made a short circuit leading to deep discharge of Lead-Acid battery.
Battery was down to 5.2V for time counted in minutes.
I've ...
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What is purpose of an Undervoltage Sensing Circuit?
I am wondering what is the purpose of an IC such as the MC34064. Is it just to ensure a reset of microcontrollers upon power up or are there other reasons? I used to make a simple transistor switching ...
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Powering 4 12V 0.45Amp fans off USB?
This question actually has a few parts.
Basically I have 4 12V 0.45 A computer fans,which I want to use in a DIY cooling pad project I'm currently working on. I know that as per the standard USB 2.0 ...
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Controlling BLDC with IR 2130 - stuck at fault, unable to reset
I'm working right now with the following circuit, trying to drive the BLDC motor with it.
I don't exactly know how it works (especially the overcurrent sensing part) and the man that designed it is ...
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Voltage Cutoff Circuit for battery based application
Here is schematic of battery charging circuit. The battery voltage at 100% charge is 4.2V and it gradually decrease and is 3.2V, discharging below 3.2V will affect the battery life.
How to make sure, ...
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Hi-voltage required for 100% SoC in LA banks?
Talking large banks of expensive true-deep-cycle cells, not the stuff you see in mass retail channels. Maybe the 6v golf cart batts from Sam's, at the "value" low end.
I think end-of-life ratings are ...
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Simple Zener diode circuit for UVLO
Please see this circuit attached in this post/.
Basically, I want to build a simple UVLO CCT for my LED controller and I came up with this circuit.
simulate this circuit – Schematic created ...
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Laptop Charger Failure during AC supply undervoltage
My Laptop Charger is rated 240V AC Voltage. While plug in the outlet the undervoltage occurs (using multitester) the voltage is 107V. At that instant my charger is very hot, right now my charger is ...
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Can undervoltage kill a circuit? [duplicate]
I was fooling around with a DFPlayer Mini MP3 player, which looks like a really nice and easy to use device.
For some reason I couldn't get mine to output sound on its speaker outputs, so I decided it ...
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Voltage supervisory circuit selection
I am trying to understand how to choose a suitable voltage supervisor IC for a given project. I have two questions:
if I have a digital IC, in its datasheet there is information about the minimum ...
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Avoid voltage drop on DC motor start-up with h-bridge
I'm trying to control a 12V DC brushed motor (4A with load ) with an H-bridge , TLE5205 datasheet ( 5A , 6A peak , 40V , integrated free-Wheeling diodes ), but when using a 3S1P lipo battery ( 11.1V , ...
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Low voltage cutoff circuit with Zener and BJT
I have a circuit that's supposed to cut off at <4V. It instead caps the voltage at 3.3-ish and reduces the voltage linearly below that.
Zener - 3.3v
Source - 5V +-5V
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Is there any benefit to using a voltage booster (such as Batteriser) on "dead" batteries?
The Batteriser [Edit: removed dead, harmful link] is a crowd-funded product intended to extend battery life by boosting the voltage. It is basically a joule thief that is in a tiny package that slips ...
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How bad is it to undervoltage a 12-volt lead-acid battery?
I had a heated discussion with a few colleagues today revolving around how low of a voltage was alright for 12 volt lead-acid battery; they were in the opinion that the low voltage warning buzzer and ...
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Help with high current single cell lithium charging
I am designing a system to charge a single cell lithium battery. It requires pass-through, path-selection, over and under voltage protection. The bottom line is this system needs to power a device ...
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To protect a LiPO cell from undervoltage, how low current is low enough?
This may seem like a topic beaten to death, but bear with me.. this is an apparently ignored wrinkle. Over the past several weeks I've been designing various circuits to protect a LiPO cell from under-...
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Motor undervoltage
In the situation of a motor losing voltage, say it's rated for 240vac, but it's only receiving 190vac, what happens in terms of the power triangle? Does current increase, does it slow down and reduce ...
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USB current limiter and under/overvoltage protection
I know recent motherboards already provide these, but lately USB ports are also available in many different gizmos (smartphone chargers, TVs, standalone players, etc.), which I am often tempted to use ...
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ST1S10 step-down regulator - can I drive the EN pin from the voltage divider?
The ST1S10 step-down regulator has an INHibit (active low) / ENable (high) input terminal, like many other DC-DC regulators.
I'd like to use it for an UVLO function. I initially thought of matching a ...
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Driving TEC below rated voltage
Can a TEC driving IC such as the MAX1979 rated for TEC voltages up to 6V be used to control a 12V TEC - can TEC work under their rated voltage, with the amount of heat moved controlled by current, or ...
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Stabilizing the UVLO feature on a DC/DC converter
Very many DC/DC controller IC's utilize an under voltage lockout feature by way of an external pin monitoring the applied voltage and comparing it with some internal reference, putting the IC into ...
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Are there any single chip solutions for single cell LiPo battery protection? If not, any references?
I can't seem to find one, but does anyone know of a single chip solution for LiPo battery protection on a single cell/3.7V battery? Looking for things like over-current/overvoltage/undervoltage ...
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Choosing values of resistive divider, versus pullup resistor value
I have a slight Catch-22 with my circuit portion shown below.
The ADM6320 is, among other things, an undervoltage detector with factory threshold of 2.93 V (thus Reset output pin toggles when VCC <...
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Choosing Fuses or MCB in 24VDC vehicle circuit
I am currently designing a 24VDC circuit for a small vehicle. I personally prefer using MCB's since they are simple to reset and easy to detect faults in the system, although i do find it rather hard ...
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Decoupling capacitor across Raspberry Pi GPIO input (+ Arduino + robotics)
I've been messing around with a robot kit from Parallax (the BOE Shield Kit), which has a 5xAA (7.2 V?) power source. The BOE shield includes its own 5 V regulator, which is used to control servos ...
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Undervolting PWM fan from 12V to 5V [closed]
What will happen if I feed a 12 Volts rated PWM fan with 5 V driving voltage?
Given all the other variables stay the same (PWM control signals) - will it reduce RPM? By how much?
What happens to the ...
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Scaling voltage to meet two conditions at once
I am using an IC (STM6600) which, among other functions that I need, is also capable of Undervoltage Monitoring. It works like this:
The IC monitors VCC in comparison to two thresholds, V_Low and ...
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Under Voltage Protection for LiPo Battery
I have a 3Cell LiPo battery which I am going to use with an RC Car, and I want to design a circuit to protect the battery cells from going under ~3.3v each. So what do you think of this design?
As ...
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Placement of undervoltage monitor and cutoff
Suppose I have a circuit running at 3.30V, supplied via an LDO regulator (e.g., ADP124), powered by a Li-ion battery. In other words:
Now, I would like to implement an undervoltage cutoff to "turn ...
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Possible to fry a circuit with a power supply under its current requirement?
I recently had someone explain to me that he was told he fried a laptop's hard disk by putting it in an external drive enclosure that was not rated to supply sufficient current. (Apparently the disk ...
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How much negative voltage is too much for a µC?
I've been attempting to measure some stuff and trying to be careful about what I feed into my microcontrollers. I've had difficulty figuring out how to keep things within perfect limits, though.
For ...
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Safe operating area for different types of battery chemistry?
I'm trying to find the safe operating area for various types of batteries; in particular I need minimum and maximum termination voltages, although information on temperature / power / current is also ...
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Do LEDs Need UVLOs (Undervoltage-Lockouts)?
I'm currently working on a project involving (I think 3mm, 1.5VDC) Infrared LEDs. However, due to my photoresistor, I think the current, voltage, or whatever (forgot) will vary greatly to minuscule ...
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11-16V DC voltage stabilization for 13.8V powered ham radio
I am looking for any resources on how to construct a relatively high power (25A, 13.8V) voltage stabilizer (or voltage booster if you like) for my 13.8V powered ham radio.
The problem I try to ...
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how to build a low-voltage disconnect switch for DC 12.4V 70A?
How can I make a device that will make the power connected as long as the voltage of the power-supply keeps over 12.4 V (adjustable) and disconnect it if it falls below?
It also must connect the ...
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Circuit to protect against undervoltage?
What is the simplest way to regulate the min DC voltage in a circuit?
Is it possible to do with zener diodes?
...
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