Conn1 is designed to allow the Emblaser buttons and status LEDs to be moved to a different location.
This was originally intended to allow the control panel to be mounted on the outside of a cover which encapsulated the entire Emblaser.
Pinouts of Conn1.
Pin 1. Not connected
Pin 2. +5V
Pin3. Connects to one side of power on/off switch
Pin4. Power LED+. This is directly connected to the main on board power LED and therefore outputs the voltage equal to the forward voltage drop of the LED. Hence this will need to be buffered to drive an auxiliary LED.
Pin5. Connects to other side of power on/off switch
Pin6. Laser LED+. This is directly connected to the main on board laser LED and therefore outputs the voltage equal to the forward voltage drop of the LED. Hence this will need to be buffered to drive an auxiliary LED.
Pin 7. Laser Switch. Switch connected between +5v and this pin.
Pin 8. Not connected.
Pin 9. Ground
Pin 10. Non connected.
What does 'buffering' mean?
Buffering in electrical world means separating the logic signal from the load in some way. Buffer circuits would have a signal input pin that caused an output pin to have the same signal logic (ie ON or OFF) but with higher current carrying capacity. So the low power signal does not get effected by the high current loads that need to be driven by the signal.
What does this mean with respect the the Emblaser 1 LEDs?
1: Simple option is not extend them and view them from their original place on the PCB
2: You remove the existing LEDs from the Emblaser PCB. This will allow extended LEDs to work correctly.
3: The LED pins are connected to the positive side of the LED on the main board. Due to the normal practice of using a resistor between the 5V signal and the LED when driving a LED, the voltage on this pin will be zero when the LED is off, or 1.5V when the red LED is on. Therefore this voltage will not drive another external LED at the same time as the LED on the main board. So you could buffer the 1.5V signal by using it to turn a transistor on. This transistor then drives an external LED through a resistor.