pulse timer control relay circuit

Today, solutions are offered for a timed control relay that utilizes Normally Open (NO) and Normally Closed (NC) contacts to manage the operation of other devices, enabling or disabling them as needed. The functionality of this circuit is based on the use of the IC555 timer to generate pulses, with a resistor R1 setting the duration of the timing period.

The described circuit operates using the popular 555 timer IC, which is widely utilized for timing applications due to its versatility and ease of use. The configuration can be set up in either astable or monostable mode, depending on the desired application. In this instance, it appears to be configured in monostable mode, where the output pulse width is determined by the resistor R1 and a capacitor connected to the timing circuit.

In this configuration, when a trigger signal is applied to the 555 timer, it activates the output pin, which can then control a relay. The relay can switch between the NO and NC contacts based on the output state of the timer. For instance, when the output is high, the NO contact closes, allowing current to flow to the connected device, effectively enabling it. Conversely, when the output goes low, the relay returns to its default state, opening the NO contact and closing the NC contact, thus disabling the device.

The timing period is primarily defined by the resistor R1 and a capacitor (let's denote it as C1) connected to the discharge pin of the 555 timer. The time period (T) can be calculated using the formula T = 1.1 * R1 * C1, where T is in seconds, R1 is in ohms, and C1 is in farads. By selecting appropriate values for R1 and C1, a wide range of timing intervals can be achieved, allowing for flexible control of the connected devices.

Additional components such as diodes may be included in the circuit to protect against back EMF generated by the relay coil when it is de-energized, ensuring the longevity and reliability of the circuit. Furthermore, a power supply suitable for the relay and the 555 timer must be provided to ensure proper operation.

This relay control circuit can be applied in various applications, such as timed lighting systems, automatic irrigation systems, or any scenario where devices need to be activated or deactivated after a predetermined period.Today we would like to offers solutions for a set time for take control relay and take NO. / NC. contact to apply to control other devices. such as disable or enable the device. function of this circuit is using IC555 to determine the pulse and a resistor R1 to the period of time. 🔗 External reference