The process of removing energy from a store, such as a capacitor or battery. Stores may be parasitic, resulting in rapid spontaneous accidental discharge, as in a static shock.

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52 views

How calculate inductor discharge time through LED?

UPDATE Overnight I realized I'd been sleeping as I read part of the textbook I've been using or at least didn't quite fully grasp the purpose of inductor volt-second balance. I added the results of ...
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1answer
47 views

250Voltage discharging turnoff circuit

I'm reconditioning my hybrid battery. To do so requires multiple complete discharges which I do not have time to be around for. To avoid damaging my battery I've been attampting to design a circuit ...
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1answer
61 views

Charging and discharging of capacitors

I simulated this circuit in TINA-TI. However I could not understand the output waveform for the negative half of the cycle. Waveform: Green- Voltage across C2 (10 u cap) Brown- Voltage across C1 (1 ...
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1answer
32 views

Discharge / Bleeder resistors

I need to size and build a bleeder resistor network or could be as simple as two bleed resistors....im not sure but I have an application where a we have a step up transformer from 120VAC single phase ...
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1answer
51 views

active bleeder circuit for capacitor discharge

I have a circuit with a large capacitor, a solenoid and an N-channel FET fed by a 60VDC supply. When I trigger the FET the capacitor discharge activates the solenoid. This all works as expected ...
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2answers
72 views

Newbie question - sawtooth signal generation - capacitor discharge via bjt

I'm trying to realize a sawtooth wave generator. The circuit is composed by an op-amp integrator which creates the ramp. Then the integrator output is chained to a comparator with a fixed threshold, ...
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1answer
53 views

Help me understand capacitor discharging

Made this question in physics stack, but maybe I'll get a better answer here. If we apply loop rule while charging the circuit we get: $$\varepsilon -iR-\frac{q}{C}=0$$ The way I understand, we ...
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3answers
96 views

Area under voltage vs time discharge curve

Will the area under a voltage vs. time graph of a battery discharge curve (with a constant current load) give the amp-hour capacity rating of the battery? Thank you.
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2answers
63 views

Will it be fine to consume 0.0058 mA from a LiPo cell after its lowest discharge voltage of 3V has been reached?

I intend to connect a 240mAh 1S 3.7v 25C LiPo Battery with a 5V Step-Up Regulator to the Arduino pro mini v5 VCC pin bypassing the linear voltage regulator. But the battery datasheet says "Never ...
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1answer
43 views

Old 9v battery - Strange Behavior

The battery in my garage door remote finally quit. Before replacing it, I measured the voltage with a digital multimeter and was surprised to find it reading 9.70v, quite a bit higher than the ...
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2answers
86 views

discharge power rail with MOSFET

I need to discharge a power rail from 3.8V to 0V within 200ms. The control signal is active low (i.e. start discharging when control becomes low). I think the easiest implementation probably is to ...
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1answer
44 views

Formulas for Specific Capacitance Measures [closed]

I am designing a charging and discharging capacitor circuit for my power harvester. What I am looking for is the time it charges and discharges respectively. When I lookev over wikia and google. ...
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1answer
75 views

How to keep capacitor from discharging in/through regulator

I'm currently working on a project where I need the MCU to be able to keep running for at least a few seconds after the power have been interrupted (in case of power outage for example). So I choosed ...
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3answers
115 views

How can I quickly and safely make defunct electronics safe and free of charged capacitors?

I am planning a movie set which will contain old circuit boards from TVs, VCR's and other old electronics. The plan is to go to several Goodwill stores and buy up all of the TV's and such that they ...
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1answer
67 views

Can I connect two rechargable LI batteries of different specs in parallel?

More specifically, can I combine a high-discharge battery with a high-capacity battery if I want periodic high discharges combined with the higher capacity? For example, if I wanted to pair a ...
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1answer
51 views

Circuit Design for Managed Draining of NiMH Cells

One of my pet peeves is the prevalence of devices powered by odd numbers of standard batteries (AA, AAA). Since I try to avoid using disposable cells and all of the chargers that I've so far owned ...
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1answer
105 views

Charging and discharging of a capacitor experiment

I set up an RC circuit and connected it with a signal generator. In the lab instructions, I was told to apply a "square wave signal" in order to see the transient response of the circuit in the ...
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0answers
141 views

Battery testing depth of discharge vs cycles

I am currently investigating the relationship between the depth of discharge of a lithium battery, the number of cycles and capacity lost. I know from literature that the lower to DOD (%) the more ...
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3answers
250 views

Difference between battery and capacitor?

Can capacitor acts like power supply, in which situations? How related are charge/discharge time of battery and capacitor? Why battery has longer discharge time compared to capacitor? Why we cannot ...
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3answers
201 views

How do I safely discharge this capacitor with broken wire?

My electric lawn mower won't start, upon inspection some wires got loose and damaged by the motor. It's a 20µF 500V capacitor. Normally I would try to short the pins with a screwdriver, but as you ...
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1answer
77 views

Is it possible to calculate capacity of a battery using a resistor

Is it possible to measure the capacity of a battery if the discharge curve of the battery utilizes a resistor as the load? For example, if a 100 ohm resistor is connected to a battery and then the ...
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0answers
33 views

How to determine load to use in a battery discharge curve

I am making a discharge curve of a battery I am testing. So for the discharge curve, what load should I use? (This was kind of answered here, but it was kind of a guess in that the load is based on ...
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0answers
81 views

How to find the cut off and maximum voltage rating of a battery

How can I find the cut off voltage of my battery (for discharge) and a maximum voltage (for charging)? Is there an equation to do this, or are these two calculate by making a discharge curve? Thank ...
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1answer
64 views

How to make a voltage vs amp-hour discharge curve

This is in regard with another question of mine, how do you make a discharge curve with the y-axis of voltage and x-axis of amp - hour?
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1answer
75 views

How to make a discharge curve

I am trying to make a discharge curve for one of my batteries that I have. All I know about it is that it is a 1.5V battery. Now if I have to make a discharge curve for it, how would I make one and ...
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2answers
139 views

Mixing same brand batteries with similar voltage

Just about everyone has heard of the problem with mixing new and old batteries, but is it safe to mix various old batteries with each other, regarded that they are the same model and brands, and read ...
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2answers
98 views

Calculating the discharge of Ultra Capacitors

Say I have two 500F ultra capacitors, connected in parallel, charged at 15V. These are the capacitors BMOD0500 P016 B01. Then say I connect the capacitors (via an inverter) to a 230V light bulb that ...
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0answers
45 views

one-sided saturation with op-amp and RC high pass filter

I am working with a photodetecting circuit built as follow: When I drive an LED ON and OFF, I get the following waveforms: Blue indicates that the LED is turned on when a voltage is high and ...
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1answer
96 views

Why capacitors lose charge over time? How to minimize it?

Capacitors lose charge over time, even when they are disconnected. Why does it happen? Is there a way to keep the charge longer, like for years. If you cover the plates with better insulator, will ...
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3answers
160 views

Electricity needed to maintain power for camera [closed]

I am not an electrical engineer by any means and do not even know the terms I should use to ask this question but basically I am trying to determine which solar panel I can use to power my camera. ...
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2answers
115 views

Quasi-peak detector

This is the circuit of a quasi-peak detector: simulate this circuit – Schematic created using CircuitLab where \$ V_{\text{sig}}\$ is the input signal. When the diode is open-circuited, ...
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2answers
92 views

How does fluorescent lamp produce audible sound when blinking?

A fluorescent lamp will often blink near end of its life. Each time it blinks it likely produces a clearly audible sound which is hard to describe but it's something in between a water dip falling ...
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2answers
863 views

Are sealed lead-acid batteries safe to use indoors?

I have a small, 12V sealed lead-acid battery. I know regular lead-acid batteries can be dangerous to use or charge indoors, due to the fumes they release and the potential for acid to leak out or ...
2
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1answer
143 views

Questions on this high frequency sawtooth generator

So I found this very basic sawtooth generator: http://www.radiolocman.com/shem/schematics.html?di=143990 I have a few questions about it: I understand that when the capacitor C_T charges fully to ...
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1answer
40 views

What are possible alternatives for a depletion PMOS

I need a fast reacting way of discharging a capacitor and I figure a simple depletion PMOS is what I need. The time at which the gate has to have a voltage to keep the depletion PMOS closed is not ...
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2answers
351 views

Estimate minimum discharge voltage in a laptop battery

The objective is to determine the best 18650 cells to replace the ones in my laptop battery. To do that, I need to know the minimum voltage the battery controller accepts before ordering the OS to ...
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1answer
93 views

What is the effect of pulsed discharge on watt hour (Wh) efficiency of lead-acid batteries?

When discharging a (lead-acid) battery you see a voltage increase (volts rise) as soon as the discharge is paused. source: http://uu.diva-portal.org/smash/get/diva2:461718/FULLTEXT01 In the quest ...
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1answer
83 views

Makeshift way to drain a battery?

I have a 3.8V mobile-phone battery that I need to discharge. However I don't have any electrical components (say led) with me. What is a crude way to do this using household items?
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2answers
75 views

capacitor discharge direction

This is probably a dumb question, but I am sort of confused. What direction does a cap discharge when a system is turned off? For example, decoupling caps that go to ground. When I shut a system down, ...
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2answers
474 views

A few questions about basic capacitor concepts

So say you a typical setup like in this diagram. How does current flow while the capacitors charge? To elaborate, what is the mechanic that makes capacitors mimic the functionality of a wire ...
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1answer
73 views

Maintaining DC voltage with more batteries

I have a circuit which i am powering with two 1.5V AA batteries that dies at 2.6V volt as the battery discharges. Reading around, i realized that even though there is energy in the batteries, my ...
0
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1answer
96 views

Reviving an overdischarged NiCd 12v battery

Some time ago I recovered a 12v 1700mAH Ni-CD battery from an ancient Commodore Amiga black and white display laptop. The laptop works perfectly when powered by a 1.5a 12v adapter, but unfortunately ...
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1answer
122 views

Ratio Between Voltage and Charge

Is there a ratio between the voltage and charge of a battery? I mean, the voltage falls slowly while the charge is consumed? Or occurs a sudden drop of voltage when the charge is at the end?
0
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1answer
83 views

Use a steel welding table to ground yourself from electrostatic discharge (ESD)?

I have a large steel welding table that I have been using as a work station to solder together my own custom PCBs. I have been using my anti-electrostatic discharge grounding bracelet and connecting ...
1
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1answer
45 views

discharge of capacitor through a current source

Assume we have a cap connected to a current source that draws a current \$I_0\$. What time would it take to discharge the cap by a voltage \$V_t\$? $$t=\frac{C \times V_t}{I_0}$$ Is this correct ...
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1answer
54 views

How to maintain equal discharging on batteries

I am currently building a robot that has one 12V battery for each drive motor. The system was originally setup so that the two motor/motorcontroller/battery systems were completely separate. After ...
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1answer
828 views

Why does a IRFZ44N turn fully on on my battery discharger while a IRFZ46N doesn't?

I've made a simple MCU controlled NiMH AA battery tester a while ago and it works just fine. The schematic below is its discharge circuit for one NiMH AA cell. Q3 is a IRFZ44N MOSFET. Signals ...
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2answers
260 views

Are BLE modules capable of working with a CR2032 battery? [duplicate]

I keep reading that the Bluetooth Low Energy modules are capable of working with a CR2032 battery for years, but their consumption is around 20mA and the max discharge of a CR2032 is around 3mA (200uA ...
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1answer
230 views

Battery Discharge

I am making a circuit to discharge an 18V Li-ion battery, with multiple cells, in order to condition it. Each 18V cell has a capacity of 100Wh when fully charged. I would like to control the condition ...
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2answers
407 views

How deep should we discharge lithium batteries to maximise their lifetime?

Recently I posted an answer mentioning the very classic "lithium batteries like partial discharges, so design your system for limited depth of discharge". But then I wondered: with partial discharges, ...