Shared Projects by CaptainUnlikely

Dali power injector circuit - an LM317(TO263)+ 5R1(2512) resistor, which will limit the current on the two DALI pins to about 240mA. Identical to DALI power board 1 but with a bigger footprint which should allow it to deliver that 240ma without the thermal limiting kicking in.

SS14+1M ensure that if power is supplied to the bus elsewhere, the LM317 will not be damaged. 1M is to get rid of leakage current from SS14, not sure if it’s required.

Dali power injector circuit - an LM317(SOT223) + 5R1(2512) resistor, which will limit the current on the two DALI pins to about 240mA. This is a tried and tested circuit, but the LM317 will overheat if you try and deliver the full 240mA for too long, as would happen if you had a dead short on the bus, or a misbehaving device. Testing on a workbench, it dropped to about 130mA after a few seconds, but obviously that will vary based on the thermal environment.

The third part is an 0603 signal diode - there only to ensure that if this board isn’t powered, and power is supplied to the DALI bus from elsewhere, that the LM317 is protected from the reverse current. Most 0603 diodes are rated for 150mA, not 240mA, so it’s fair to say this board design does work, but hasn’t been stressed to the full 240mA output.

Note pin1 is labelled 12V but is really 12-20V, and pin2 is also labelled 12V but should be GND!

See DALI power board 3 for a revised version with a larger footprint LM317, for better thermals.

This is the power injection circuit from Microchip AN1465. It limits the output to 70mA, which is not enough for a full bus of 65 units at 2mA each. Decreasing the resistor by much just overheats the parts.

A circuit to replace the electrics in a Yamaha 703 Outboard Motor control. See http://captainunlikely.com

Control board for a Danfoss BD-35 fridge compressor. See http://captainunlikely.com/blog/tags/fridge for details.