12V DC Relay (5 Pin)

Wiring Connections:

• Pins Overview:
  • Pin 1 (Coil Positive): Connects to the positive terminal of the 12V DC power source to energize the relay coil.
  • Pin 2 (Coil Negative): Connects to the negative terminal of the 12V DC power source.
  • Pin 3 (Common): This is the common contact of the relay switch. It connects to the load or device you want to control.
  • Pin 4 (Normally Open, NO): This contact is closed when the relay coil is energized. It connects to the power source for the load when the relay is activated.
  • Pin 5 (Normally Closed, NC): This contact is connected to the common pin when the relay is not energized. It provides an alternate path for the load when the relay is off.

Power:

• Power Requirement: Requires a 12V DC power supply to operate the relay coil.
• Power Consumption: The relay coil  consumes around 0.1 to 0.2 watts. This translates to a current draw of approximately 10 to 20 mA at 12V DC.
• Switching Capacity: The relay can switch loads with currents up to 10 Amps or more, depending on the model. Check the specific relay datasheet for exact switching capacity.

Input and Output:

• Input: The input is the 12V DC power applied to the relay coil through Pins 1 and 2. This energizes the coil and causes the relay to switch its contacts.
• Output: The output comes from the relay’s switching contacts (Pins 3, 4, and 5). When the relay coil is energized, the common contact (Pin 3) connects to the Normally Open (NO) contact (Pin 4), allowing current to flow to the load. When the relay is not energized, the common contact connects to the Normally Closed (NC) contact (Pin 5).

Physical Characteristics:

• Dimensions:  small, with a compact form factor to fit into standard relay sockets or mountings. Dimensions can vary slightly based on the manufacturer.
• Mounting: Usually designed to be mounted on a PCB (Printed Circuit Board) or in a relay socket. Some models may come with mounting tabs or brackets.
• Enclosure: Often encased in a plastic or resin housing that provides protection for the internal components and helps with insulation.

Technical Specifications:

• Coil Voltage: 12V DC
• Coil Resistance: Generally between 60 to 100 ohms
• Switching Current Rating: Usually up to 10 Amps or more, depending on the specific relay model
• Contact Configuration: SPDT or DPDT (check model specifics)
• Operating Temperature Range:  -40°C to 85°C, but verify with the datasheet

Additional Features:

• LED Indicator: Some relays come with an LED indicator to show when the relay is energized, providing a visual confirmation of operation.
• Protective Diode: Often, a diode is placed across the relay coil (flyback diode) to protect against voltage spikes caused by the collapsing magnetic field when the relay is de-energized.

How to Use:

• Connecting the Relay:
  • Power the Coil: Connect the positive terminal of the 12V DC power supply to Pin 1 (Coil Positive) and the negative terminal to Pin 2 (Coil Negative).
  • Connect the Load: Attach the load to Pins 3 (Common) and 4 (NO) if you want the load to be active when the relay is energized. Use Pin 5 (NC) if you need the load to be active when the relay is off.
• Testing the Relay:
  • Power On: Apply 12V DC to the coil and check if the relay clicks or switches. This indicates that the relay is energized and the contacts have changed position.
  • Check Contacts: Measure continuity between Pins 3 and 4 to confirm they are connected when the relay is energized. Measure between Pins 3 and 5 when the relay is de-energized.
• Installation: Mount the relay in a suitable location where it can be securely attached and where the connections can be easily accessed. Ensure proper ventilation if the relay is in a confined space to prevent overheating.

The 12V DC relay with 5 pins is a versatile component widely used in electronic and electrical projects for controlling high-current loads with a low-current control signal. Its ability to provide isolation and reliable switching makes it a valuable tool for various applications.