Can I Use A 12v Relay In A 24v System?

How does a 24v DC relay work?

In this relay, when a current flows through the coil, it turns it into an electromagnet.

The magnet pushes a switch to the left, forcing the spring contacts together, and completing the circuit they’re attached to.

This is a relay from an electronic, hot-water immersion heater programmer..

How can I tell if a relay is bad?

Symptoms of a Bad or Failing Ignition RelayCar suddenly stalls while operating. One of the most common symptoms of a failed ignition relay is a car that suddenly stalls while operating. … Car not starting. Another symptom of a faulty ignition relay is a no power condition. … Dead battery. A dead battery is another symptom of a faulty ignition relay. … Burned relay.

How do you tell if a relay is bad with a multimeter?

The only tool required to check a relay is a multimeter. With the relay removed from the fuse box, the multimeter set to measure DC voltage and the switch in the cab activated, first check to see if there are 12 volts at the 85 position in the fuse box where the relay plugs in (or wherever the relay is located).

How much voltage is needed to trigger 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.

How many amps does a 12v relay coil draw?

The current draw of the coil is not normally shown but is typically 150-200 mA with a corresponding coil resistance of around 80-60 W. Tip: Knowing the coil resistance is useful when testing the relay for a fault with a multi-meter. A very high resistance or open circuit reading can indicate a damaged coil.

What is 87a on a relay used for?

87 and 87a are the two contacts to which 30 will connect. If the coil is not activated, 30 will always be connected to 87a. Think of this as the relay in the Normally Closed (OFF) position. When current is applied to the coil, 30 is then connected to pin 87.

Will a 12v relay work with 5v?

For 12V relay, you have to use 12V supply voltage for energizing the relay coil. On the other hand, for 5V relay it is 5V. If you provide the right supply, arduino is capable to drive both the relays.

How do you test a 24v DC relay?

How to Test a 24 Volt RelayIdentify the terminals on the relay module. There will usually be five, but many types exist and different styles may be more common for certain applications. … Apply voltage from the 24 volt battery to the coil terminals on the relay using alligator clip jumpers. … Set the ohm-meter to continuity test mode.

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…

How much current is needed to change a relay?

To stay within the power rating, a signal with a maximum voltage of 250V, should have a current of no more than 240mA. Most relays, therefore, have a complex useful working area. The higher the switched voltage, the lower the maximum switch current must be for a relay to handle it safely.

Can I use 12v for 19v?

19V is generally going to fry any device that was designed to run at 12V (especially consumer products). And while it’s not very likely it might also catch fire. For a AC adapter to work you will need one with the exact voltage (12V) and an equal or higher current rating (1.5A or more).

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 do you check if a relay is working?

Listen for a click when the relay is energized. Check the energized condition of the relay contacts. Use a digital multimeter (DMM) to test the resistance between each pole of the relay and the corresponding NC and NO contacts for that pole. All NC contacts should read infinite resistance to the corresponding pole.