Introduction: Big LED Signal Lamp for Fischertechnik

About: I live in Braunschweig, Germany with 3 children. We love to build and experiment.

Fischertechnik used usually normal lamps. Normal light bulbs are expensive and break down quickly.
In fischertechnik be led little be used.
Somehow fischertechnik is not as timely. That's a shame. LEDs can be very easily integrated into fischertechnik.

Step 1: Parts

I used  two Kingbright BIG LAMP with 20mm diameter.
It is a very large LED. Ideal to display something.
The LED is available in different colors.

The kids like them very much.

The LED consis of 6 single LED. 3 in a row. 2 in parallel.
The supply voltage is 6 volts, the current 20 mA.

We need a series resistor of about 150 ohms.


Red LED:     Part Number: DLC2/6ID
Green LED: Part Number: DLC2/6GD


Other Parts:

- one or two 150 Ohm Resistor (for 9 Volt)
- 2,6mm Märklin sockets (Can be replaced by cable)
- prototyp pcb
- epoxy or hot glue

Step 2: Circuit

If we use a fischertechnik controller, we can operate the two LED anti-parallel. Depending on the polarity of the drive output red or green LED lights. We need then to control only one pin.
We just need a series resistor.

For general applications, it is better to control both LEDs separately.

The series resistor is calculated for 9 Volt fischertechnik.

Step 3: Contruction

First, we drill the holes for the LED 2. A proto-type board is helpful. But it is also without. We solder the LED and the resistor. If necessary, we also have a separate copper track. The separated wires led us to use for the attachment of the sockets.

For mechanical stabilization, we shed the back with epoxy or hot glue.

Step 4: Action