Table of Contents
Overview: Lamp Dimmer Circuit using IC 555 Timer
In this project, we will learn about a simple and efficient PWM Lamp Dimmer Circuit utilizing an IC 555 Timer. We can also create the dimmer using the linear regulator IC. However, the issue with such dimmers is that they can only achieve maximum efficiency of 50%. However, PWM-based dimmers can reach above 90% efficiency.
Heat loss is reduced due to the high efficiency. As a result, the switching parts of PWM dimmers necessitate a smaller heat sink. The tiny heat sink minimizes the overall size and weight of the gadget. So, in this tutorial, we’ll build a 12V PWM light dimmer with a NE555 IC, two switching transistors, and a diode.
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The 555 Timer-based circuit only applies to DC circuits with a limited voltage range. This circuit cannot be used with AC dimmers.
Materials used for this project
The following are the materials needed to complete this project. All of the components are simply available on Amazon.
|0.01uF Ceramic Disk
|555 Timer IC
Simple Lamp Dimmer Circuit
The PWM Lamp Dimmer Circuit Using an IC 555 Timer is shown below.
The NE555 timer is wired as an astable multivibrator in the circuit above and operates at a frequency of 2.8KHz. The timing components are the two 1K resistors in series with the 50K variable resistor and the 0.01uf capacitor.
The Potentiometer RV1 is used to modify the duty cycle of the IC’s output. The greater the duty cycle, the brighter the lamp, and the lower the duty cycle, the less illuminated the light.
During the charging cycle of the astable multivibrator, the 1N4007 diode bypasses the lower part of the variable resistor.
The diode ensures consistency of the output frequency regardless of the duty cycle.
The Darlington driver stage for the 12V light is formed by transistors Q1 and Q2 (2N5551 and TIP41, respectively). The 1K resistor limits the base current of the 2N5551 transistor.