Auto Electrical Relays Explained - How they work and where they're used.

Summary

This video explores the function and applications of auto electrical relays, which act as switches controlled by a small electrical current. Central to a relay is an electromagnet that, when energized, closes contact points to allow high power circuits to operate. A special type, the double-throw relay, can switch between normally open and normally closed contacts, commonly used in vehicles for switching between low and high beam headlights.

Takeaways

• 🔌 Relays are electrical switches controlled by a small current.
• 🚗 They are commonly used in vehicles for high power circuits like spotlights.
• 🧲 The core component of a relay is an electromagnet that operates the switch.
• 💡 When energized, the electromagnet attracts an armature blade to close the contact points.
• 🔋 The relay allows a larger current to flow through its contacts when the small switching current is applied.
• 🔄 Advanced double-throw relays, or change-over relays, have two outputs: normally open and normally closed.
• 🔄 In rest position, the normally closed contacts allow current to flow to the circuit.
• 🔄 When activated, the electromagnet breaks the current to the normally closed contacts and opens the normally open side.
• 💡 The double-throw relay is often used in car headlights to switch between low and high beams.
• 🔍 The script explains the basic operation and applications of auto electrical relays in a clear and concise manner.

Q & A

What are auto electrical relays?

Auto electrical relays are switches that are turned on or off by a small electrical current, and are used in vehicles for various applications, including the switching of high power circuits.

What is the primary function of a relay in a vehicle?

The primary function of a relay in a vehicle is to control the switching of high power circuits, such as spot lights, using a small electrical current.

What is the core component of an auto electrical relay?

The core component of an auto electrical relay is an electromagnet, which when energized, attracts an armature blade and closes contact points to allow current flow.

How does an electromagnet in a relay affect the flow of current?

When the electromagnet in a relay is energized by a small current, it attracts the armature blade, closing the contact points and allowing a larger current to flow through to the high power circuit.

What is the purpose of the contact points in a relay?

The contact points in a relay allow the flow of current from the relay to the high power circuit once the electromagnet is energized and the armature blade closes the contacts.

What is a double throw relay, and how does it differ from a standard relay?

A double throw relay, also known as a changeover relay, has two outputs: one normally open and one normally closed. It differs from a standard relay by allowing current to switch between these two states when the electromagnet is energized.

In what position does a double throw relay allow current to flow from the source to the circuit?

In the rest position, the normally closed contacts of a double throw relay allow current to flow from the source to the circuit.

How does a double throw relay switch from one state to another?

When the electromagnet in a double throw relay is energized, it attracts the armature, breaking the current to the normally closed contacts and closing the contacts for the normally open side of the relay.

What is a common application for double throw relays in vehicles?

A common application for double throw relays in vehicles is to switch car headlights from low to high beam.

Why are relays preferred for high power circuits instead of direct switching?

Relays are preferred for high power circuits because they allow the use of a small switching current to control a much larger current, reducing the risk of damage to the control system and providing better control.

How does the relay ensure continuous operation of high power circuits?

As long as the small switching current continues to flow to the relay, the larger current will flow through its contact points, ensuring continuous operation of the high power circuits.