Small 12v headlight relays?

[MC Bodge]

I'm looking for suitable, physically small relays for switching the high and the dipped headlamp wiring on my Street Triple motorbike.

Space is tight and small (40A?) ones might fit next to the small switching relays under the tank.

Suggestions please.

Thanks.

[phillpot]

Some Micro relays here but max 25A


Same here

and here

Edited by phillpot on Monday 8th September 20:00

[Mr2Mike]

You really shouldn't need a 40 Amp relay for the headlamps, a 25 Amp micro relay should be perfectly sufficient.

[andyiley]

Power = current x voltage, therefore

40 amp relay will therefore allow the relay to power a circuit using 480 watts assuming 100% efficiency.

I don't think you have headlights of over 400 watts!

Assuming you are switching 1 x standard halogen headlight you will only need to supply less than 6 amps, 2 will need less than 12 amps.

You can therefore use smaller relays with no issues at all.

[MC Bodge]

andyiley said:

Power = current x voltage, therefore

40 amp relay will therefore allow the relay to power a circuit using 480 watts assuming 100% efficiency.

I don't think you have headlights of over 400 watts!

Assuming you are switching 1 x standard halogen headlight you will only need to supply less than 6 amps, 2 will need less than 12 amps.

You can therefore use smaller relays with no issues at all.

Thanks. Yes, I do know the equation for power.

I have twin headlights:
2 x dual filament H4s. On flash, with all filaments (assuming 65W bulbs, although they will probably be 55W) it will be closer to 20A, albeit for short periods.

The automotive relays I do have are all labelled as 40A.

[Mr2Mike]

MC Bodge said:

Thanks. Yes, I do know the equation for power.

I have twin headlights:
2 x dual filament H4s. On flash, with all filaments (assuming 65W bulbs, although they will probably be 55W) it will be closer to 20A, albeit for short periods.

The automotive relays I do have are all labelled as 40A.

You'll need one relay for dip and another for main beam, so the current through each relay will only be half that.

[MC Bodge]

Mr2Mike said:

You'll need one relay for dip and another for main beam, so the current through each relay will only be half that.

Quite right! I know this, but stupidly thought and wrote it wrong. Oops.

I'm trying to fit 2 relays in, which is the point of using smaller ones.

Lower current ones should do.