Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [constant-power]

A circuit designed to supply or consume a constant level of power. Contrast with constant-current and constant-voltage.

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Is there a constant power supply?

A voltage source is a device that produces constant voltage, but allows amperage and power to vary, in accordance with the laws of electricity. A current source is a device that produces constant current, allowing voltage and power to vary. Is there…
PyRulez
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Constant power load SPICE model

I would like to create a SPICE model for a constant power load. I'm guessing that would involve using an equation to dynamically adjust the model's resistance based on the applied voltage. How do you do this in SPICE? (I'm currently using Eagle but…
Jeremiah Rose
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Constant Power Loads in LTspice

Could someone help me understand what is happening in B1 when stepping between P = 2.9 W and 3.0 W?
MemorX86
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Calculating voltage and current of constant wattage loads along a very long cable

I am struggling with a calculation where I'm either missing something really simple or the maths is advanced beyond my current capability. I have tried rearranging wattage / ohms law calculations but to no avail. Can anyone please assist? I have a…
Christopher Ringwood
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Equipment for analyzing large DC distribution system

I'd like obtain the transfer function of a large DC power distribution system. My question is whether there's equipment (like vector network analyzers) designed to assist with modeling these type of applications. Most equipment seems to be for…
effectual_healing
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Converting appliance LEDs from constant current to constant voltage to allow for dimming

I'm trying to implement dimming control for the lights in my kitchen hob extractor. The lights are 4x LED spotlights which are each 3v 700mA (2.1W). They are currently wired in series to a 700mA 10W constant current LED driver. The LED dimmer module…
Garywoo
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Power Supply for ESP12F WiFi Module

I am using ESP12F to drive LED array circuit for dimming and other functions. Supply from LED driver is constant current for LED array. What does ESP12F requires? Constant current or Constant voltage? And what should be minimum amp I should take…
MICRO
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Constant power supply with high-voltage "restrike"

I'm still playing with electrolytic chemical reactors. After looking at the results from a constant-current circuit I'm realizing that what I really need is a constant power supply because, depending on the reactor conditions and setup, it can take…
feetwet
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Applications for Constant Power Source

Consider a SMPS with a control loop that uses an analog multiplier to control its output voltage in order to maintain a constant power output. I am trying to figure out some of the applications where this operating mode is more beneficial than…
user187594
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Need uninterrupted power to car power socket, even during ignition on/off, direct battery tap only option?

I have a carputer setup with a Nexus 7 tablet and a Carlink wireless carplay adapter connected via OTG splitter cable to the tablet. I have a problem in which the carplay dongle needs constant power to operate properly without resetting itself which…
Scott B
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Driving a WS2815 12V LED strip with a CC+CV driver

I am selecting a driver/PSU to power a string of WS2815 12V LEDs. WS2815 datasheet here: http://www.world-semi.com/DownLoadFile/138 One option I am looking at to power these strips is the Mean Well HLG-320H-12. HLG-320H-12 datasheet here: …
WowtaH
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Why constant current led driver is not used in parallel led strip?

I know that the constant current led driver is not used in the parallel led strip. and constant voltage led driver is not used in the series led strip. can anyone explain me with the example that why this scenario is followed? Thank you
Shashikant
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Capacitor charging efficiency with a constant power source

It is easy to derive the efficiency for loading a capacitor from a constant voltage or a constant current source, basically because exponential functions and constants are very, well, integration-friendly. However, what is the efficiency for…
Nucleonix
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Voltage drop on string of constant-power loads: Simulation issue?

I've noticed something that seems odd to me in an LTspice simulation (see below). I'm trying to model a system with a number of identical devices which each draw ~11W (with negligible variation over different input voltages) and are separated by…
MrWhippy
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Effects of current/voltage limiting of LEDs

First of all, I have read many articles about the non-linear effects of voltage vs current of LEDs. I also know that current will rise as temperature rises, batteries have resistance, LEDs brightness is not linear. All in all, LEDs are finicky…
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