Car Spotlight Circuit

Relay-based car / motorcycle floodlight circuit to keep the light bright and not make the current switch heavy. I'll explain it one part at a time as easily as I learned a train mechanic.

1. Main equipment in the circuit

In the picture, there are the main devices as follows:

Battery (Battery 12V)

Is the power supply of the system.

Fuse (Fuse)

The green body following the battery

Acting to prevent fire shock. If the overcurrent is absent immediately

Relay (Relay 4 Legs / 5 Legs)

It is an electrical switch that uses a controlled electromagnet.

Switch On Light (Switch)

Use to control the relay.

Highlights / Headlights

It's a high-current load.

Ground (Ground)

Is the negative pole of the train system.

2.Relay leg used in circuit

The standard relay will have 4 or 5 legs.

Legs

Duty

30

Get the fire from the battery.

85

Relay coil terminal

86

Relay coil terminal

87

Send the lights out to load.

87a

(Some models) Normally power supply.

In the picture, use 30 / 85 / 86 / 87.

3. Principles of circuit operation

Step 1: Fire out of battery

+ 12V power out of battery

Passing through.

Fuse → to the 30th leg of the relay.

Reasons to put a fuse

Burn Line Protection

Short circuit protection

Step 2: Relay control circuit

This section uses little current.

Fire trail

Battery

→ Switch

→ Leg 86 of the relay

Leg 85 of the relay.

Continue Ground

When the switch is pressed,

The fire will flow in. Coil relay.

Magnetic fields occur.

Step 3: Relay works

When the coil works,

The contacts in the relay will

Weld the legs 30 and 87.

Make the fire from the battery

Flow to the floodlights immediately.

Step 4: Light to lamp

Fire from

Leg 87 → To Floodlight

Then

Fire out of the tube.

→ Down Ground

Complete circuit

Stick lamp

4. Why use relays?

If not using relays

The fire from the battery will pass directly through the switch.

The problem is,

The switch can't handle the current.

Hot wires

The lights are not fully lit.

The relay allows

The lights are up.

The switch doesn't burn.

Safe system

5. Current flow (simple summary)

When the light is on

The fire path is

Bat + → Fuse → Leg Relay 30

Relay works → 30 against 87

87 → Highlight → Ground

Control circuit

Battery → Switch → 86

85 → Ground

6.Cord color in image (generally)

Color

Meaning

Red

Positive fire from the battery

Black

Ground

Yellow

Relay control line

Blue

Switch cable

7. Advantages of this kind of circuit

✔ The lights are brighter.

✔ The switch doesn't break easily.

✔ The wires aren't hot.

✔ safer.

8. Power sample

If you use a spotlight,

2 stars

55W each

Total force

110W

Current used

110 × 12 9.2A

So should use

Relay 30A

Fuse 15A

# Car warning lights # Car Spotlight Circuit # Good content is useful # Car # Ritspeed