Remote piezo switch, taskled lflex

[yorkie_chris]

I'm thinking of putting a driver in the battery canister, it would make life easy.

But, it would be nice to have a switch on the light head. Do you think it would work to have the piezo wires running with the power wires? Easy enough to use some 4 core cable. Has anyone tried similar?

Would be very helpful if you could use the LED earth as one of the switch wires, but I don't think oyu can do this with Lflex.

 

[Deeperdiverdude]

I suspect that you will have problems with the close proximity of the power wires and the switch wires.
TaskLED dont recommend having long switch wires as they act like an antenna and pick up stray emfs causing the driver to switch erratically.
Suggest you contact George at TaskLED, he's always helpful
T

 

[alpg88]

^ that actually makes sence.

but if op insists, using shielded twisted pair may help, if it becomes an issue. some alarm cables have few pairs each, individually shielded.

 

[yorkie_chris]

Decided to put the piezo on the canister instead to save the potential hassle!

 

[Deeperdiverdude]

Are you using a prolonged piezo to be able to do short and long clicks?
If so be careful how close it is to the driver, I built a unit and had lots of probs with interference and had to revert to a standard piezo switch

 

[arek98]

Long cables may act as antenna and cause switching. Some new TaskLed drivers have schmitt filter for switch (e.g., H6Flex). If you have one without it you can add small ceramic capacitor (e.g., 10nF) between switch wires close to driver, it will filter out high frequency noise.
For piezo I would use it always as well.

 

[lucca brassi]

some general guidelines http://www.melexis.com/Asset/Automotive-LED-driver-Guidelines-for-EMC-DownloadLink-5444.aspx , http://cds.linear.com/docs/en/application-note/an139f.pdf

 

[Exswede]

Thanks everyone very informative, as with everything on this forum :twothumbs