Problem driving a laser pointer

[Jumper]

Hi,

Are you sure the TIL is fully open? 4.7k as the LED resistor seems a bit much.

Bring out your DMM and measure the voltage on the TIL to see what is happening.
/me

[Louis Cimon]

Hi Jumper,

Thank you for your input.

I changed the resistor for a 470 ohm.

I am reading 4,92 v between rb0 and ground
and 4,92 v between TIL111 pin 1 and ground

I am reading 8,35v between TIL 5 and battery and the battery produces 8,35 v.

I tested my piezzo on two 9v batteries in series and the sound output is greatly reduced when I drive it with the TIL111 compared to driving it directly with the batteries. The voltage readings of the batteries and the TIL11 output are the same.

Solution?

[Jumper]

Hi,

Why do you want to use this optocoupler? If you just want to switch something on with the PIC I would go for a FET solution.

ULN2001 is a favorite at this forum and if you only want to handle up to 500 mA this will do fine.. IF you need more you can use more channels in this chip in parallell.

You can also try to measure the current thru the laser to compare it with and without the TIL.

/me