Mini 9v Christmas Tree
Another low-cost kit, this is a simple Christmas Tree with 3 LEDs and two resistors powered by a 9v PP3 battery. The markings on the back of the PCB make it particularly easy to get the orientation of the LEDs correct and there’s scope for a number of measurments using a multimeter, if you want a bit of theory. Can be supplied with an on/off switch upon request. See the Prices and Ordering page for details.
Brief soldering instructions:
- Start by soldering the two resistors in place – the resistors are identical and they can be inserted either way round.
- Solder the three LEDs in place, ensuring that the LED’s long wire goes in the hole marked with a ‘+’ symbol. To make things easy, the holes are marked ‘LONG’ and ‘SHORT’ on the reverse of the PCB. Note that a piece of tape can be helpful to hold the LEDs in place whilst you solder them.
- If your kit comes with a switch, solder it in the three holes in the top corner of the PCB. If you have the version without a switch, there should be a small blob of solder next to the middle of the three hole (see the top-right of the photo). This blob bridges two pads on the PCB: if it’s missing, add it now by heating both pads with your soldering iron and applying a little solder.
- You can now solder the battery clip by passing the wire up from behind the PCB and then pushing the tinned end of the wire down into the holes in the corner. Make sure the red and black wires go to the correct holes as indicated on the reverse of the board.