Reed Switch for dive Light Help

[frozenwarp]

Hi all,

I need any help i can get on using a reed switch for a dive light,

I would really like to see pics and details of any that people have made

I would also really like a wiring digram of a reed switch with a realay

And lastly, what size magnets are people using any links to supppliers for reed switch parts (are people using magnets from DX)

Thanks in advance,
Bradley

 

[Packhorse]

Cannister build. - CandlePowerForums

Using a MOSFET as a Switch

The amount of magnets depends on the reed switch being used and the distance from the reed to the magnets.
In my above can ( which is being held up untill I get my DX 8mm magnets) I will be using 6 or so.
The less the better or you can increase interference with compasses.

You can use either a MOSFET or relay. MOSFETs work out cheaper and you dont need to find one with the correct operating voltage as you would with a relay. They are also smaller. Anyway in the above pic D1 and R2 represent the LED and driver. So all you need is 1 resistor and the MOSFET.
I use N channel FET p16nf06 or irf1405

 

[haibeis]

Matey

try the Jaycar electronics mini reed switches , part no. LA5074

i have used these to great effect.

they handle up to about 700ma so i have used them with
3w LED's with no relay.

2 handy things:

the magnet is enlosed in plastic so will not rust and is easily mounted.

the reed is 'normally closed' so will pass current unless a magnet is present.
this is really handy if the magnet happens to break off underwater.