Strange Output resistance on K8055

I’ve had my Velleman K8055 for a while now.
Always used it for input to my computer.
Wanted to control a simpel circuit with the output on the board.

I took a small flashlight en connected two wires to the switch ends.
So when the wires touch the circuit is completed and the light burns. Very simpel.

I took those wires and connected them to the Ground and output 01 on my velleman Board.
When I open K8055 demo tool and select output 01 the light starts to burn, but very very dim.
So the electricity is flowing, but only a little. It seems the port isn’t opening completely.

What’s wrong?

Maybe you have quite low voltage battery in the flashlight.
There on the K8055 digital output remains about 0.75V residual voltage when activated.

Please be sure not to overload the digital output. It is specified only for 100mA current max.

Thanks for the reply, only when I close the circuit without the velleman board the light is bright.

The light has three aa batterys producing about 4,5 volts.

What are the specifications of the bulb? Current, power ?

3.6 V 0,75 Ahk

The current of this bulb is too high: 750mA
The transistor array ULN2803 at the digital output of the K8055 is specified to 500mA max.
Here a link to the datasheet of the ULN2803:
datasheetcatalog.org/datashe … 828_DS.pdf