# Quick Answer: How Much Voltage Does A Relay Need?

## Do I need a relay for rock lights?

Your fine if you just hook up your switch straight to the lights.

A typical 50 watt light will consume a little over 4amps.

As long as your switch (and wire size, and fuse size) is rated for however much total current your ciruit will consume, your okay without a relay.

This place USED to be fun..

## How does a relay fail?

In fact, the life of a relay is essentially determined by the life of its contacts. Degradation of contacts is caused from high in-rush currents, high- sustained currents, and from high voltage spikes. … Relays can also fail due to poor contact alignment and open coils.

## How do I choose a relay rating?

An easy way to determine the limit of a relay is to multiply the rated Volts times the rated Amps. This will give you the total watts a relay can switch. Every relay will have two ratings: AC and DC. You should determine the AC watts and the DC watts, and never exceed these ratings.

## Can I use a 12v relay in a 24v system?

It is also possible to use a 12V relay in a 24V circuit by inserting a resistor of the proper resistance and wattage in series with the coil. Drop 12V across the resistor and that leaves 12V for the relay coil. This trick only works well with DC relays and not AC relays.

## How a relay works 12v?

When voltage is removed from the coil terminal the spring pulls the armature back into it’s ‘at rest’ position and breaks the circuit between the terminals. So by applying or removing power to the coil (the low current circuit) we switch the high current circuit on or off.

## Do I need a relay for fog lights?

Relays are an important component in wiring fog or driving lights with a 30-60A draw. Basically, the relay protects the switch from getting hot and creating unwanted resistance. The low current through the switch triggers the relay to make a higher current connection to the heavy load of the fog lights.

## What is a 12 volt relay?

12 Volt Automotive Relays. Automotive relays are for use in 12 volt electrical systems. Relays are used when you need to switch higher currents than a switch can handle, or when you want to isolate an electrical circuit. Our relays have either 5 contacts or 4 contacts.

## Will a 12v relay work with 9v?

Description. This circuit allows a 12v relay to operate on a 6v or 9v supply. Most 12v relays need about 12v to “pull-in” but will “hold” on about 6v.

## How fast is a relay?

There are many considerations involved in the correct selection of a control relay for a particular application, including factors such as speed of operation, sensitivity, and hysteresis. Although typical control relays operate in the 5 ms to 20 ms range, relays with switching speeds as fast as 100 μs are available.

## What is 85 on a relay?

85 and 86 are the coil pins while 30, 87, and 87a are the contact pins. … Realizing that 85 and 86 are the coil pins, these pins will be transferring the current through the coil. 85 will be used to ground your relay, while 86 will be connected to the switchable power.

## How many volts does it take to activate a relay?

Most are rated at 12v, usually a range of 12-15v. Actual voltage required to operate the relay is usually a little under 12v. That is why your accessories can still operate with the key on and engine off, usually making actual voltage a bit under 12v with lights on.

## Do I need a relay for LED lights?

A relay is an electrical switch that lets a low current circuit control a high current circuit such as a large LED light bar. … If you are using a light pod that does not have a very large amp draw, you may not need a relay switch, but if you are using a larger LED light bar, they are a must have.

## Why do LED lights need a relay?

Relays can be used to switch a low-current trigger to high current, switch a circuit on or off, reverse polarity, and much more. When adding LED lights, such as off-road light bars, driving/work lights, or other auxiliary lights to a vehicle, you must add a circuit to power the light adequately.

## Does a relay increase voltage?

Nonetheless, relays can “control” larger voltages and amperes by having an amplifying effect because a small voltage applied to a relays coil can result in a large voltage being switched by the contacts.

## Why use a relay instead of a switch?

A relay is nothing more than a remote switch that uses an electromagnet to close a set of contact points. … Relays are often used in circuits to reduce the current that flows through the primary control switch. A relatively low amperage switch, timer, or sensor can be used to turn a much higher capacity relay on and off.

## Does a relay need constant power?

The answer to that one is No. Relays have finite life time in terms of how many times they can open and close. And limit to how much current they can handle. But keeping a relay constantly energized does not wear it out.

## How does a 5v relay work?

The other side has three low voltage pins (Ground, Vcc, and Signal) which connect to the Arduino. Inside the relay is a 120-240V switch that’s connected to an electromagnet. When the relay receives a HIGH signal at the signal pin, the electromagnet becomes charged and moves the contacts of the switch open or closed.

## How do you make a 12v relay module?

DIY Relay Module MakingStep 1: 12V Relay. Buying Link. … Step 2: PCB Board. I have used Dot PCB Board. … Step 3: Any PNP Transistor. Use any PNP Transistor Which Can Handle 20mA At least. … Step 4: PC817 Opto-Coupler. PC817 Opto-Coupler. … Step 5: Resistor. 10k Resistor Link. … Step 6: PCB Mount Screw Terminal Block. … Step 7: Push Switch. … Step 8: Indicator LED.More items…

## Will 5v trigger a 12v relay?

Is it a lighted switch. There is no other reason for the voltage being cut down by the switch other than you having it wired through the lamp in the switch.