Author Topic: Illuminated fire button sx350 (Read 8804 times)

Zoomer · « **on:** August 26, 2014, 07:29:26 AM »

I'm a bit lost trying to figure out how to wire a momentary led switch so it only light up when you press the fire button.

Is it safe to do it this way ??

Appreciate the help

Breaktru · « **Reply #1 on:** August 26, 2014, 10:32:51 AM »

The fire button sends the fire pin on the board LOW. Meaning that a negative polarity will fire the board. The jumper is correct and the circuit should work fine.
The resistor value is determined by looking at the LED specs and using the voltage source, diode milliamps and diode forward voltage formula.
See: http://led.linear1.org/1led.wiz

Zoomer · « **Reply #2 on:** August 26, 2014, 11:17:00 AM »

Ended up doing it like this. I know the drawing is really confusing and messy.

JLIT · « **Reply #3 on:** September 02, 2014, 02:06:48 AM »

Appreciated. Thanks for posting your schematic

warlordxxx · « **Reply #4 on:** September 03, 2014, 10:40:31 PM »

This version would be much easier - You might have to change the resistor value depending on the forward voltage of the switches LED - Quick question though - Why the mosfet in your diagram ?

Zoomer · « **Reply #5 on:** September 04, 2014, 07:02:28 AM »

Quote from: warlordxxx on September 03, 2014, 10:40:31 PM

This version would be much easier - You might have to change the resistor value depending on the forward voltage of the switches LED - Quick question though - Why the mosfet in your diagram ?

Thats same as the pic I posted but some don't recommend it.

Zoomer · « **Reply #6 on:** September 04, 2014, 07:14:26 AM »

Quote from: warlordxxx on September 03, 2014, 10:40:31 PM

Why the mosfet in your diagram ?

In your diagram the current is going back in to the chip via the switch wires, the mosfet is detecting current going to the 510 and then sending current to the led so nu currunt is going back into the chip, its a safer way to do it.

Ive done it the way you described and had no problems but on other forums they don't recommend it as it could hurt the chip. Better to be safe than sorry.

daveymist · « **Reply #7 on:** September 05, 2014, 07:11:09 PM »

Seen a circuit that you can make. Transistor hooked up to the atty when the voltage is hit on it it allowed LED to light from battery. Only things used where wire, transistor and resistor.