The Stack Overflow podcast is back! Listen to an interview with our new CEO.

Questions tagged [constant-current]

Questions regarding Constant Current supplies, devices and applications. As opposed to Constant Voltage supplies. Voltage will vary while Current remains the same. Common in LED lighting applications.

Filter by
Sorted by
Tagged with
2
votes
0answers
61 views

How to protect a CONSTANT current DC motor from stalling?

What would be an efficient way to protect a DC motor that draws CONSTANT CURRENT (always 300mA) from self destroying when stalled for too long? Or is this even necessary on brushed DC motors? On other ...
0
votes
0answers
29 views

Constant current converter for variable voltage source and load [closed]

Does there exist a device or circuit that can take a constant current device and output a current with a direct ratio to the input? Regardless of voltage. So a load that requires a constant current ...
6
votes
1answer
117 views

Voltage Controlled Current Source - help needed

I am designing a voltage controlled current generator for the currents in a range from 0 - 2.5mA. The load resistance is within the range of 0 - 5k Ohms. I decided to go with difference amplifier ...
0
votes
1answer
41 views

Constant current source for an alternating magnetic field of varying frequency and constant amplitude from a solenoid

The project I am working on requires me to oscillate my sensor. I am doing this by coating a ferromagnetic material on the sensor and applying a sinusoidally varying magnetic field. I was applying the ...
2
votes
2answers
77 views

How to fix this constant current drive circuit?

I have selected a constant current source to drive LCD in my design but doesn't work well, so I'd like someone to help me pinout where the problem is. The LCD backlight requirement is as below.The ...
1
vote
1answer
150 views

How to limit current while almost keeping voltage same

I am supposed to design a power supply to a project. I have 3 alternative power supply designs for this purpose. However, one of them sucks huge current while giving enough current. My design is given ...
0
votes
0answers
58 views

Bi-directional constant current using analog switch

I am trying to build a bi-directional constant current source with a h-bridge configuration. As you can see in the attached figure, I am controlling the direction of current on the load using PWM ...
0
votes
0answers
66 views

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 ...
0
votes
2answers
82 views

How should I make a constant AC current source to drive an electromagnet?

The inductance of the electromagnet is about 0.05H and the resistance is under 50 Ohm and I need about 2 to 5 Amperes to drive it. I need to be able to change the amplitude and also the frequency at ...
0
votes
2answers
56 views

Pulsed DC current measurement using arduino and shunt resistor

I am currently working on a project ( to develop a constant current pulsed DC supply) in which current has to be measured using Arduino's analog input (Upto 20A) passing through a variable resistance ...
0
votes
0answers
34 views

EV charging and charging station

An EV battery first charges through CC(Contant Current) method and then through CV(Constant Voltage) method. So this way of charging is made sure by the circuitry on board the vehicle for Level 1 and ...
0
votes
2answers
156 views

Homemade Li-ion charger

I am trying to build a lithium battery charger (Li-Ion) for charging banks of 6s batteries of varying capacities (2-30Ah) from a varied DC input. Given that I need to supply CC/CV to charge these ...
2
votes
3answers
83 views

Dim LED lamp with constant current power supply using resistors

I own a really bright led lamp that I want to dim. It is powered by a constant current power supply that can supply 37mA between 11V to 17V. If my lamp is connected the voltage settles at 13.58V. ...
0
votes
1answer
62 views

Repairing an old Bench Power Supply

I have an old PS-303D from Conrad in use at home. Recently it showed a problem. If I measure with my multi from V- to V+, the voltage reading is correct, current and voltage regulation seems to work ...
0
votes
2answers
47 views

Calculating charge time of a large capacitor from a boost with a limited power source

I am trying to work out the math of what is the highest cap voltage or capacity I can have to charge from a boost topology in a given time from a source of 5V, 500mA. Here is a rough sketch of what I ...
1
vote
2answers
78 views

Constant current load circuit? (20 amp) [closed]

I'm pretty new to stack exchange and I've only just gotten my basic circuit analysis classes done in college. For my school's solar racing team, I've been tasked with designing a constant current load ...
0
votes
3answers
90 views

Can someone explain this constant current load circuit?

I'm currently a rising junior in EE and I was just wondering if anyone could help explain this circuit for me. The purpose for this is because I need to learn how to build a discharger (constant ...
3
votes
2answers
93 views

Why does my Current Regulative Diode not regulate current well?

I recently ordered several E153 CRDs from Semitec (data sheet here) to maintain a steady current to an LED (data sheet here). Mistakenly, I didn't read the "Dynamic Characteristics" portion of the ...
0
votes
0answers
20 views

Producing Bi-Phasic Constant Current Pulse using L293 IC

I am trying to convert a current source output into the bi-phasic pulses. I thought maybe using L293 IC might help to change polarity of the currents. Here is the picture of design: as can be seen ...
0
votes
0answers
35 views

Removing Overshoots in constant-current bi-phasic pulse generator

I am designing a constant-current, bi-phasic pulse generator in a simulation study. I have attached the circuit and output current pulse. As it this picture shows, I have a +600 to -600 micro Ampere ...
1
vote
1answer
52 views

Can I use a voltage controlled resistor to adjust high side switch current?

A number of high-side switches (e.g. the NCP380) go into constant-current mode when the programmed maximum current is reached. This is typically set with an external resistor according to the required ...
0
votes
2answers
217 views

How do I design a constant current load circuit?

I'm currently a rising junior in EE and am honestly completely lost... I've been tasked with designing a constant current load circuit to discharge parts of the battery pack for Georgia Tech's solar ...
0
votes
1answer
50 views

Constant Current Output driver connected to 2 COB LEDs - is the hookup valid?

I have a lamp with this hookup. Can someone confirm whether the electrical specs match up such that these can be connected in this way. ld009d-cu03036-m9 - MagTech Constant Current 24-36v output ...
0
votes
1answer
60 views

Deciphering which COB LED used in a circuit [closed]

I have two lamps with identical LED circuits. The lamps sometimes blink when turning on. One of the lamps already has a blown COB LED. I suspect the wiring was done wrong. I've opened it up, but I ...
1
vote
1answer
169 views

When to use analog PID

So I am building a rather simple constant current load to test power supplies. I am using an INA138 for high-side current measurement with only 5V power (and I have reasons for that, unfortunately) ...
0
votes
1answer
78 views

Topology choice for wide-output-voltage-range SMPS

I'm intending on building a off line (230VAC), 50W, isolated, constant-current switch mode power supply. This by itself is not a big challenge with the plethora of application notes and examples ...
1
vote
1answer
71 views

Current source with multiple “taps” for driving different LEDs

I'm building a light source for a (one-off, hobby) 8mm film scanner that will be taking several exposures of each frame with different color (R, G, B, and possibly IR) light. I'd started with high-...
0
votes
1answer
129 views

How to select the best opamp for a constant current MOSFET driver

I'm trying to create a constant current LED driver. I have found and read information about the miller effect and came up with the schematic below. What are the most important parameters for choosing ...
0
votes
0answers
449 views

Solar charger for lithium batteries

I am trying to build a 2s 7.4V solar charged lithium battery pack to power an arduino UNO and SIM900 GSM shield. I have a 12V, 10W solar panel, BMS protection board and a DC-DC CC CV buck converter ...
0
votes
1answer
106 views

Variable Constant Current Supply

I've been looking around for a good CCS schematic, and decided to try making a simpler one even if it means it'll behave worse. I need a 12V (would come from an ATX power supply, more than enough ...
2
votes
0answers
54 views

Calculate the junction temperature of a MOSFET during pulse

Hi all I have a question regarding using a MOSFET for a constant current source. I have found this question with some answers but it wasn't clear to me yet. I want to create a constant current LED ...
1
vote
2answers
77 views

Figuring out the principal working of constant current source

I've the following circuit: simulate this circuit – Schematic created using CircuitLab I was told that this is a constant current source. I think that the resistors \$\text{R}_1\$ and \$\text{...
0
votes
2answers
53 views

Adding push button to CC DC to DC converter to adjust CC

I have a CC/CV DC to DC converter I bought on aliexpress. I does not come with a screen so I attached to it an LED voltmeter ammeter. Anyway everything works fine. One thing though, I don't know at ...
0
votes
1answer
294 views

Adding Current limit for DIY DC-DC converter (CC/CV battery charging)

I was following the circuitry by great Scott for the DIY buck converter here: https://www.youtube.com/watch?v=m8rK9gU30v4 . Created a converter that gives 0-23V on 24V supply. After this i wanted to ...
1
vote
1answer
216 views

Constant current source with shunt fet

I'm want to create a project with a LED strobe with IR LEDs. As LEDs the Osram SFH 4249-UV will be used in strings of 15 LEDs and 32 strings parallel. This results in a Vf of 34.5 - 45 V and a If of ...
0
votes
1answer
56 views

Constant Current Regulator position in a series circuit

I'm designing a circuit with 3 LEDs, a CCR (NSI50350), and a power supply in series. My question is: Does it matter where I place the CCR? Can I design my circuit this way: +V--LED1--LED2--CCR--LED3-...
-1
votes
1answer
174 views

in zener diode current source, to provide constant current, what resistor, etc do I have to use?

I have a load that has varying resistance and want to know the change of resistance by measuring the voltage with constant current. The figure below is known to provide constant current. But I have no ...
0
votes
2answers
93 views

Led driver high current and voltage

For a project I have to design a led beacon that will consist of +400 LEDS. These LEDS will be driven only a short amount of time maximum of 3% duty cycle (frequency: 100Hz, pulse: 300us). The LEDS ...
4
votes
2answers
660 views

Digital Current limiting with MCU

All current limiting circuits I've found until now use some sort of analog Logic with Op-Amps to limit/control the current. (Why) is no digital current limiting used? I would imagine a shunt resistor ...
0
votes
0answers
41 views

SMPS topology for combination of current controlled rail and fixed voltage rail

I'm looking at designing a LED driving power supply that can interface with a universal AC main input (~90VAC-260VAC) and produce 2 rails at the output; one a current controlled rail, and the other a ...
0
votes
2answers
589 views

Constant current led dimming

I have a few panel lights which come with normal non-dimmable constant current drivers. I want to add a dimming feature to them, please suggest me a circuit that I can use with Arduino/ESP8266 to ...
0
votes
0answers
185 views

Constant Current LED Driver Output Control using PWM

I want to control the brightness of a led which is powered by a constant current driver. On utilizing a MOSFET and pwm signal from an arduino uno the led starts to fade in as the duty cycle ...
0
votes
1answer
54 views

Driving 8 x 117W COB LEDs [closed]

I am currently attempting to design a LED grow light using the following LEDs but I am having a very hard time finding a sufficient power supply. 8 x Lumileds - SunPlus CoBs DataSheet 51.7 V, ...
-1
votes
4answers
125 views

Capacitor bank as a constant current source?

Can a capacitor bank of high power density, be integrated to a circuit such that it acts as a constant current source to a load? Even for a short duration of time.
1
vote
4answers
235 views

Constant current source gets heated

I am trying to control some power LEDs using a microcontroller. For this I plan to use a transistor based constant current source to protect the LEDs from getting damaged and PWM on the base of the ...
0
votes
2answers
430 views

Why constant current led driver is not used in parallel led strip? [closed]

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 ...
1
vote
1answer
131 views

AL8860 LED driver does not output required constant current

The LED driver circuit i've made here does not output a constant 1A current. With an input voltage of 12V and 9V total Vf on the three LEDs (CREE LED star), the current is only 0.65A. Am I ...
0
votes
0answers
85 views

Calculating value of a current limiting resistor in a constant current circuit?

I am using 12 leds in series with 3.0-3.4 v forward voltage and 400-500mA forward current (these values are from the datasheet). I am using a constant current led driver(24-40v and 580mA). My problem ...
0
votes
4answers
268 views

Inductor with constant current source

Hii can anyone explain how to do this. Its Given Answer as 6A. What exactly happens when a constant current source in series with inductor? TIA
0
votes
3answers
70 views

Constant Current Load fails to recover after setting load to zero

I'm trying to design a Constant Current load for testing battery cells using the TLC070 Op Amp (what I happen to have on hand) and a low pass filtered (150Ohm + 470uF cap) PWM input from an Ardiuno. ...