piezo swith problem


I’m working on a custom canister dive light and I have an odd issue.
I use Cree XHP 70 6v, piezotg from taskled, LD3 driver and 2s5p 18650 battery.

1. I connected the led (XHP 70 6V) and the piezo latch circuit directly to the battery (2s5p lion) without the led driver. The measured current
was around 6A. I could switch ON/OFF the light by pressing the piezo button without any problem.

2. I connected the led to the battery with the led driver and without the piezo latch circuit. I could “switch” ON/OFF and change modes by breaking and reset
the connection between the driver and the battery.

3. If the driver and the piezo latch are togethet in the circuit I can switch ON/OFF only at lower modes. If the led runs in 100% mode it is not possible to switch OFF. It also does not matter if there are other modes in the group or 100% is a single mode in a group, the phenomena is the same.

Has anyone experienced similar things with piezo switches?

Is this dry, or underwater? There was a thread on diving lights where people reported glitches when underwater. Basically, saltwater was making an unintentional connection, or something like that.

Try Ultrafire DV-S9 diving light? as a starting point.

i know of some various piezo components from electronics.

i naturally know what a switch is.

of all the many and varied types of switches? i cant recall ever running across a piezo switch? but it dopesnt shock me, there are as many different types of switches, as there are blades of grass, i sometimes think, from being exposed to basic electronics.

It is dry.

I replaced the piezo button by a simple momentary action switch.
Same problem, still can not bee switched off at high mode.

Hmm, that’s a stumper. Unless the higher voltage and higher current just latches it on or something.

Thank you for the suggestions, finally I could solve the problem and the dive light is ready to use.

Finally I decided to have an own piezo latch circuit.
An electrical engineer is working on it. Unfortunately the developement is quite slow but I hope it will be available soon.
It will have LVP, reverse polarity protection, temp. control, short circuit protection, sleep mode and can switch at least 8 amps.

Meanwhile I also “developed” a simple latch circuit, it seems to be working fine but I would like to test it more.
It does not have any advanced features as described above, it is just a latch circuit.
I will order the pcb soon.

Unfortunately piezo switches works differently neverthless they are from the same manufacturer.
So at the moment I think that the latch circuit always has to be calibrated for the given piezo switch.

for sure you have kill switch …. what is max current you can drive you through? Normal current for that switch is from few mA to 1 A max - signal output not power output

the max. current is 15A