Alarm system

[fionn1432]

Hi

All so I'm planning to put a alarm system in my campervan and going to run it from the leisure battery. From a 12v 2x 5v usb socket. The alarm pannel runs on 5v and the siren 5v. I have pics attached on here also would it be safe to have it left on constantly from the 12v 2x 5v usb socket.

Thanks

 

[footsoldier]

I always find either Practical Motorhome - or Camperavan magazine - to be very helpful on these matters.

 

[fredrussell]

you could use a buck voltage converter to bring 12v from leisure battery down to 5v. 12v supply to buck would need to be fused as close to battery as possible.

Pardon our interruption...

 

[Stemar]

What is the power draw of the siren? Could the USB gizmo cope with the alarm and the siren simultaneously?

 

[jakew009]

Use a couple of these:
Amazon.co.uk

 

[fionn1432]

What is the power draw of the siren? Could the USB gizmo cope with the alarm and the siren simultaneously?

5v

 

[fionn1432]

you could use a buck voltage converter to bring 12v from leisure battery down to 5v. 12v supply to buck would need to be fused as close to battery as possible.

Pardon our interruption...

 

[Stemar]

5v

It isn't the voltage that matters - that's right, or it isn't, but the current. USB chargers, especially cheaper ones, tend to have a limited current output, and the rated current is often shared between the two sockets, so a twin socket 5 amp charger might only give 2.5a for each.

I was just wondering, if the siren draws too much power, there may not be enough left for the alarm, which might give problems. fredrussel's suggestion of a buck converter or two would overcome the problem - if it really is a problem.

 

[fionn1432]

It isn't the voltage that matters - that's right, or it isn't, but the current. USB chargers, especially cheaper ones, tend to have a limited current output, and the rated current is often shared between the two sockets, so a twin socket 5 amp charger might only give 2.5a for each.

I was just wondering, if the siren draws too much power, there may not be enough left for the alarm, which might give problems. fredrussel's suggestion of a buck converter or two would overcome the problem - if it really is a problem.

I might buy one of those looks the safer option the one buck with the circuit board. I'd say the siren would run on 3v. So what fuse would I use for this buck