Introduction: Simple & Easy Dimmer Circuit Using 555 IC for LED Strip Lights

In this tutorial i will show you how to build a dimmer for the LED Strip Lights using 555 IC.

To build your own Dimmer Circuit using 555 IC you can watch the video embedded in this step or continue reading

Step 1: Parts List

Picture of Parts List

***Parts List***

1. 555

2. 0.1uF Ceramic Capacitor - 2

3. 1N4007 - 2

4. 8 Pin IC Holder

5. 47k Ohm Pot

6. Resistor (1k & 120 Ohm)

7. BC547

8. PCB & wires


***Purchase or Affiliate Links***


1. LED Strip Light -

2. 555 IC -

3. Pot Knob -


1. LED Strip Light -

2. 555 IC -

3. Pot Knob -

Amazon USA

1. LED Strip Light -

2. 555 IC -

3 .Pot Knob -

Amazon IND

1. LED Strip Light -

2. 555 IC -

Note: all the purchase links provided are affiliate links

Step 2: Circuit Diagram

Picture of Circuit Diagram

Construct the circuit diagram as shown in the circuit diagram. The circuit should be powered above 10 volts & the voltage should not exceed more then 14 volts. To control the brightness you can use the pot.


FedericoC26 (author)2017-11-07

Really Interesting!
I have a question...
There are some resistors in the circuit but what is it the value of watt of the them?
1/2W? Or more? Do I need to choose the same value of the led strip?

bkeskin (author)2017-09-30

instead of using tip31, is it possible to use an N channel mosfet(ex. irlz44n) in order to get more current?

MakeStuff_MS (author)bkeskin2017-10-10


VlatkoS2 (author)2017-08-17

I want to add a tip 31 transistor what kind of resistor should i use in R2,

because i use 120 ohms and led strip doesn't go up to full brightness

MarceloG19 (author)2017-08-15

It is a good call to use a 555 for this application. In this times paople tends to abuse of microcontrollers in detriment of real electronics.

Pics, Attinys, Arduinos and other products come and go, but 555 will last for ever!

MakeStuff_MS (author)MarceloG192017-08-16

That's for sure.. 555 timer can be used in so many application like light detector, dark detector, schmitt trigger, timer & many more.

nodoubtman (author)2017-08-11

You should use a n channel mosfet

MakeStuff_MS (author)nodoubtman2017-08-16

Yup. Mosfet can handle higher currents

johnm1 (author)2017-08-08

Each LED in the strip uses 6.7 ma. The transistor specified has a maximum current rating of 100ma, which means it can only power 15 LEDs. The video shows of roll of LEDs being powered. Am I missing something or is a different transistor being used?

MakeStuff_MS (author)johnm12017-08-08

No, The transistor used is same as shown in the circuit diagram.

The transistor specified has a maximum current rating of 100ma which is true & its not ideal for lighting more then 15 leds but if you refer the datasheet - maximum current rating - continuous is rated at 100ma. Since we are using PWM there is no flow of current continuously (this is where i took the advantage of this transistor).

Now coming to the drawback of using BC547 - with duty cycle 50% or above you cannot use this for long time for that you need to replace BC547 with the transistor like TIP31.

Nutellabrot (author)2017-08-07

Could you explain, how this works, please?

MakeStuff_MS made it! (author)Nutellabrot2017-08-07

For dimming the LED's i am using PWM (Pulse width modulation). The dimming is achieved by turning On & OFF the led's at high frequency. I shared the PWM waveform for the circuit diagram shown in this tutorial which has duty cycle approximate to 47%. You can vary the duty cycle using the 47k Pot.

To learn more about the PWM you can refer the following link -

Maker Saga (author)2017-08-02


MakeStuff_MS (author)Maker Saga2017-08-03

Thank You

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