Question about adding switching mode to variable constant current circuit

Thread Starter

jaychicc

Joined Dec 6, 2023
2
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hi. I have a question while studying a adjustable constant current circuit.

The circuit above is a reference from YouTube(ZAFER YILDIZ). [
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I tried configuring the circuit and it works well. But I'd like to add a few things.


1. I want to connect it to Arduino and turn it on/off with a signal.
I disconnected Q1-R3 and applied the N-Ch Mosfet switching circuit.
It doesn't work. What should I do.

2. When the 1K Potentiometer is set to minimum (0R) and the LED is connected
A small amount of current flows. Is there any way to prevent this?

3. Is it possible to operate by changing the potentiometer to an I2C type dgital potentionmeter?
 

Ya’akov

Joined Jan 27, 2019
8,973
Welcome to AAC.

The first question is, “what problem is this circuit meant to solve?” Why are you building it, what will it do for you when you are done?
 

Thread Starter

jaychicc

Joined Dec 6, 2023
2
Welcome to AAC.

The first question is, “what problem is this circuit meant to solve?” Why are you building it, what will it do for you when you are done?
First, configure the lighting(LED) controller circuit.
The previously constructed circuit used simple switching using an n-ch mosfet.
However, there were limitations as the specifications of each connected light were different.
Therefore, we are currently reviewing the constant current method.

I'm not good at English, so I used a translator. sorry.
 

bertus

Joined Apr 5, 2008
22,264
Hello,

The citcuit will likely work for low currents.
For high currents a huge heatsink will be needed, as it is a linear regulator that will create a voltage drop at the given current accross the fet.
The fet needs to dissipate that power.

Bertus
 

Ya’akov

Joined Jan 27, 2019
8,973
First, configure the lighting(LED) controller circuit.
The previously constructed circuit used simple switching using an n-ch mosfet.
However, there were limitations as the specifications of each connected light were different.
Therefore, we are currently reviewing the constant current method.

I'm not good at English, so I used a translator. sorry.
It is hard to understand exactly what you are saying but if you are looking for a constant current LED driver, you might want to consider the TI TPS9612 CC LED driver with PWM control for dimming.
 
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