soft latching FET based tail clicky switch

[antoninodattola]

Now that I think about it,

I have the electronic key for the V11R

Kuku, if someone wants to, I could take some pictures;)

[HKJ]

@WarHawk-AVG

Has anyone ever ran across the idea of making a high current FET based soft latching power switch PCB as a replacement for the clickies switches?

You see it once in a while, but the usual problem is getting power to it in a tube shaped light with the switch at the rear.

Some solutions I have seen:

• A extra tube inside the light for powering the switch.
• Always use pwm, that never reach 100%, use the off period to collect power.
• Use a capacitor to collector power when the light is off.
• A small battery in the switch.

It is much easier with a side switch at the front of the light, like Fenix, Olight and other is doing.

[lagman]

@HKJ

@WarHawk-AVG

Has anyone ever ran across the idea of making a high current FET based soft latching power switch PCB as a replacement for the clickies switches?

You see it once in a while, but the usual problem is getting power to it in a tube shaped light with the switch at the rear.

Some solutions I have seen:

• A extra tube inside the light for powering the switch.

• Always use pwm, that never reach 100%, use the off period to collect power.

• Use a capacitor to collector power when the light is off.

• A small battery in the switch.

It is much easier with a side switch at the front of the light, like Fenix, Olight and other is doing.

If people really want a rear switch then it would be possible to place the FET at the front with the driver and run two very thin wires to the back clicky switch.

[comfychair]

@lagman

This is a good idea, but it would work best if the FET is placed between the battery and driver. This way you can connect to the positive (button top of the cell) and negative (ground ring of the driver). That way a coin cell is not needed.

In that case just use a driver with momentary switch firmware. No latching FET switch required.

[WarHawk-AVG]

@comfychair

@lagman

This is a good idea, but it would work best if the FET is placed between the battery and driver. This way you can connect to the positive (button top of the cell) and negative (ground ring of the driver). That way a coin cell is not needed.

In that case just use a driver with momentary switch firmware. No latching FET switch required.

The whole point of the FET is they are capable of pushing more current than some clickies…

[comfychair]

My point is, if you solve the how-to-power-the-latching-circuit problem by relocating the switch to the front between B+ and driver, that's utterly pointless. Just use a momentary switch driver.

[comfychair]

http://kfdown.s.aliimg.com/kf/HT1lP8vFTXaXXagOFbXQ/121130677/HT1lP8vFTXaXXagOFbXQ.jpg

The Maglite XL50 does something similar, using a 3AAA carrier with dedicated power pins at the rear of the carrier and into the tail switch circuit.

[alternety]

A small super capacitor could store power for a fairly long time.

[comfychair]

[Mattaus]

What you want to do is easy from an electrical implementation point of view, but very tricky from a packaging and power point of view. Trust me - I know.

You've come across and discussed most of the problems I encountered. My switch is very nearly ready, I'm just struggling to find the time to actually test my latest (and hopefully final) revision.

The switch I linked to above is designed specifically for SureFire/SolarForce hosts, but there is no reason why it can't be re-designed for other lights. Depending on where it's placed we can even do away with the coin cell.

Also note my switch was originally designed to be dual-momentary (forward and reverse momentary) and I LOVE IT for that reason alone as it's great for use with light UI's that require lots of clicking to set certain features. The high current capability is nice to have as well :D

- Matt

[WarHawk-AVG]

@Mattaus

What you want to do is easy from an electrical implementation point of view, but very tricky from a packaging and power point of view. Trust me - I know.

You’ve come across and discussed most of the problems I encountered. My switch is very nearly ready, I’m just struggling to find the time to actually test my latest (and hopefully final) revision.

The switch I linked to above is designed specifically for SureFire/SolarForce hosts, but there is no reason why it can’t be re-designed for other lights. Depending on where it’s placed we can even do away with the coin cell.

Also note my switch was originally designed to be dual-momentary (forward and reverse momentary) and I LOVE IT for that reason alone as it’s great for use with light UI’s that require lots of clicking to set certain features. The high current capability is nice to have as well

- Matt

Awesome!!! Very cool!

Solid state clicky excellent!

[RMM]

I built one *clobbered together* that fit in a 20mm spot. I used two 3 volt button cells in series for power and a momentary switch with only two levels. .off and full on. We already have all the parts to do it, but the packaging is messy and the batteries are an issue. The better solution is just to forego the tail clicky and just go full momentary.