Hello everyone,

I developed a project to dim an led from 0-24v by using a controller and it is working fine. Now i am looking for a circuit without controller. could someone suggest something on this.

My input voltage to board is 24V and LED will also work 24V i want to DIM LED from 0 to 24V without controller

 

hi S,
What is the operating current of the LED.?
E

 

2 Ampere

hi S,
What is the operating current of the LED.?
E

 

i want to DIM LED from 0 to 24V without controller

So you want to dim, but you don't want circuit that implements dimming.

A Venetian blind, a pull window shade..... (being a smartass)

How do you want to actually tell LED to dim, a pot, a sensor.....? But no circuits ?


Regards, Dana.

 

So you want to dim, but you don't want circuit that implements dimming.

A Venetian blind, a pull window shade..... (being a smartass)

How do you want to actually tell LED to dim, a pot, a sensor.....? But no circuits ?


Regards, Dana.

I want to use pot for dimming and mosfet or relay to turnoff the led. I required smooth dimming from 0 to 24v

 

If you are not concerned about power loss, a simple transistor follower circuit will do the job for the dimming, and a simple switch can turn on and off, or operate a relay.

A power rheostat would also work.

After that things get a little more involved…

 

... i want to DIM LED from 0 to 24V without controller

Can you explain what you mean by this? If you are dimming the LEDs, by definition you are using a "controller".

I think you mean you want to eliminate an expensive? or clumsy? device you have used successfully and replace it with something cheap? or small? or ... what? What are you really trying to accomplish?

Most people would recommend a PWM-based controller for smooth dimming of LEDs. It's the state-of-the-art solution and many commercially available dimmers exist. They are not expensive and are hard to beat. What improvement are you looking for?

 

Google is your friend.


Look up NE555LED dimmer

 

A 24 volt 555?

A 222 driving 2 Amps?

 

Hello,

Or you could have a look at this thread:
Project: Simple PWM circuit

You could use a 78L12 to power the 4093 from the 24 Volts line.

Bertus

 

Can you explain what you mean by this? If you are dimming the LEDs, by definition you are using a "controller".

I think you mean you want to eliminate an expensive? or clumsy? device you have used successfully and replace it with something cheap? or small? or ... what? What are you really trying to accomplish?

Most people would recommend a PWM-based controller for smooth dimming of LEDs. It's the state-of-the-art solution and many commercially available dimmers exist. They are not expensive and are hard to beat. What improvement are you looking for?

i am dimming the LED by using Arduino controller now i want to do by using Potentiometer & without controller. LED input voltage is 24V

 

Hello,

Or you could have a look at this thread:
Project: Simple PWM circuit

You could use a 78L12 to power the 4093 from the 24 Volts line.

Bertus

Thank You will check

 

A 24 volt 555?

A 222 driving 2 Amps?

i didn't get your point? can you brief me

 

hi Sc,
A 2N2222 transistor cannot control a 2Amp Collector current.
The circuit in post #8, was posted as just an example of a dimmer, it will require a higher power output transistor or MOSFET.
E

 

hi Sc,
A 2N2222 transistor cannot control a 2Amp Collector current.
The circuit in post #8, was posted as just an example of a dimmer, it will require a higher power output transistor or MOSFET.
E

Ok

 

Sorry Saiteja chinthalapati I was referring to the circuit in post #8 that won’t work because of two reasons.

 

i tried all your suggestions but i am not getting correct output. Please suggest some other circuits which are robust

 

Whose suggestions are you referring to? What did you try that didn’t work? What was the result?

The circuit in #8 is valid but requires a couple minor changes for driving a 24V, 2A load.

 

i tried #8 and #10. in #8 i changed the resistor value and in place of 2222A transistor i have taken MOSFET

 

Sorry Saiteja chinthalapati I was referring to the circuit in post #8 that won’t work because of two reasons.

What are those reasons and what changes we have to made