How to use a 555 relay timer module

How to use a 555 relay timer module

In this tutorial, we will explore how to use a 555 relay timer module to control an AC or DC load, allowing you to set a delay of up to 10 seconds before the load is activated. This can be particularly useful in various applications where timed control is necessary. We will go through the hardware components, wiring instructions, and expected

NE555 12V relay timer — NE555 12V Relay Timer

behavior of the module.

Hardware Explained

The 555 relay timer module consists of several key components, including a 555 timer IC, a relay, a multi-turn potentiometer, and indicator LEDs. The 555 timer IC is responsible for generating the timing signal that controls the relay. When the timer reaches the set time, it energizes the relay, allowing current to flow to the connected load.

The relay has two main states: normally open (NO) and normally closed (NC). Depending on how you connect the load, the relay can either allow current to flow when activated or interrupt the current flow. The multi-turn potentiometer adjusts the delay time, allowing for fine-tuning of the timer settings.

Datasheet Details

Manufacturer	Generic
Part number	555 Timer Relay Module
Logic/IO voltage	5–15 V
Supply voltage	12 V
Output current (per channel)	10 A (AC), 15 A (DC)
Peak current (per channel)	15 A
PWM frequency guidance	Not applicable
Input logic thresholds	Low: 0–1 V, High: 2.5–15 V
Voltage drop / R_DS(on) / saturation	0.1 V (typ.)
Thermal limits	Up to 85 °C
Package	Module
Notes / variants	Multi-turn potentiometer for time adjustment

Ensure the relay is rated for the load you intend to control.
Adjust the potentiometer slowly, as it is a multi-turn type.
Do not exceed the voltage and current ratings to avoid damage.
Use proper heat sinking if the relay gets hot during operation.
Be cautious of high voltages when working with AC loads.

Wiring Instructions

To wire the 555 relay timer module, start by connecting the power supply. Connect the VCC pin to a 12V power source and the ground pin to the negative terminal of the power supply. The relay control pins are typically labeled as NO (normally open), NC (normally closed), and COM (common). Depending on your application, connect your load between the COM and either the NO or NC pin.

Next, connect the potentiometer to the designated pins on the module. This potentiometer will allow you to adjust the timing of the relay. Ensure all connections are secure, as loose connections can cause erratic behavior. If you are using a microcontroller to trigger the relay, connect the appropriate control pin to the trigger pin on the module.

Demonstration / What to Expect

When powered on, the relay timer module will wait for the specified delay before activating the relay. You can expect the relay to click on after the set time, allowing the connected load to power on. If the potentiometer is adjusted, the timing can be changed, which should be reflected in the relay's operation. Be cautious of floating inputs; ensure your control signal is defined to avoid unexpected behavior (in video at 5:00).