a while ago I opened a topic called connecting bell boxes.. got some excellent feedback from pete @ wakefield security..

In Pete's reply he give me a solution to my problem but said I would need to check the output current consumption for the bell boxes in alarm condition, and make sure they don't exceed the total current value.

I checked the current values (in alarm condition) and for the 2 boxes and the internal sounder it came to 1.09A but the bell board is rated @ 1A..

As it's just over the rating can I just put a high rated fuse in the board or do I have to use the other solution that Pete give me, which was to use an external power supply tripped by a relay ???

Hi Diyking

Thanks for the mention, as it is just over does it blow the one amp fuse? (its best to let it ring for a few mins to be sure)

I have seen bigger rated fuse's put in pcbs to get over this problem. But I wouldnt do it personally.

If it doesnt blow the 1 Amp then your ok, if it does and you over rate it, then the worse that can happen is the output transistor blows

I would also reduce the bell ringing time (that way your not putting such a strain on the system for too long)

Pete

Thanks for the reply again Pete,

I've not tried it out yet, but i'll give it ago..

another question i've got.. if I set the bells to ring for say 15mins, is this 15mins from the last sensor activation or is it from the first.

Also after the 15mins of the system being in alarm the bell switches off and then 20mins later another PIR is activated will the bell re-sound...