Remote Power Control Unit

(exercise extreme caution if creating one of these units due to direct connection to the power line)

This device controls the power to 8 individual outlets. There are 16 power levels available for each one.

Connection is made via 9600 baud serial using a din-5 connector. A single byte sets the power level for any of the 8 channels. Also, a global command sets all the power levels at once.

A device like this is effectively the 'back end' for many projects. By using different 'front end' systems, it could be a color organ, theatrical lighting device, home mood lighting controller, or anything else you like it to do.

As you see from the schematic , it receives its power using transformerless circuitry floating directly on the power line. You need a 1:1 isolation transformer at a minimum to build one of these devices. Often, using a 60 volt isolation transformer is desirable: you get enough power to test the circuit without exposing yourself to full line voltage while testing and construction.

The data connection is made via opto coupler using a standard 5 pin DIN connector. Since this is an optically coupled, balanced line, it is wired identically to a MIDI connector (but at a different data rate). It connects directly to either rs-232 or TTL serial at 9600 baud. (See hookup diagram on schematic).

Commands are all singe bytes as follows (this supersedes any notes in the file):

Bit 7        Global if set
Bit 4-6      Select channel 0-7
Bit 0-3      Set power level 0-15

Bit 7 is normally cleared and the channel number and power levels are set at the same time for a single channel. If bit 7 is set, the power level is applied to all channels at once (a nice way to turn everything off).

Source file and Object (hex) files are provided as usual, as is the board Layout and Parts Placement.