Step 5 : Control Methods – Hill 320


This controller uses a combination of flip flop chips and decoder chips. Details can be found in the HowTo titled “How To Build A Parallel Port Controller Box.” Essentially how this system works is that the PC issues a series of commands that tell the chips which channels to control and whether they should be on or off using an electronic routing system. All of the flip flop chips receive the same data, but the decoder chips will decide which one should actually use the data. Once the data is stored, that chip will then keep it until the next command is received. That data lets the chip know which of its 8 channels should be on or off. This lets you control more than just 12 channels from a single parallel port. In fact, you can scale it out to 1000’s of channels from a single port. As in the other controllers, the controller chips will switch relays on/off to control the lights.

Pros: Expandable system with more than enough channels for the average person. Only one parallel port is needed.

Cons: You will need a large number of chips and the circuit boards will be fairly complex.

Cost Breakdown: You will need to purchase all of the chips and decide how you want to connect them (either point-to-point or using printed boards.) You will have costs for wire, boards, chips, box(es), and the additional cost of the relays and cords or outlets/boxes.

Step 6 : Control Methods – Olsen 595

Step 7 : Horning Dimmer

Step 8 : Control Methods – Renard Dimmer

Step 9 : Relays


To this point, everything I've mentioned has been DC current. Now that you have a controllable channel/output, you need a way to switch 115v AC house current (depending on the country you live in.) If you live in a country that uses DC house current, you could switch the lights using something like transistors or MOSFETS. Assuming you have AC, there are 2 options here. The first is to put the AC on the controller board. The second is to seperate it off onto additional boards. Regardless of the method chosen, you will need to use a relay. That can be one that is assembled using an opto-isolator and a triac or it can be a preassembled unit. Either way, it's still a solid state relay (SSR). Mechanical relays can't switch fast enough and have limited lifespans. The relay lets a DC signal switch an AC current while keeping the two seperated. You don't want AC running back into your control system and frying your PC.

If you run the SSR's on the controller board, you will need extension cords/cable capable of carrying AC current from the controller to the light strands. If you run the SSR's seperately, you will need extension cords/cable capable of carrying AC current to the external boards as well as the additional control cables. This can lower the number of power cords you need, and will let you put the power close to the lights such as at the base of a tree. A single Cat5 (8 conductors) cable can control up to 7 channels, but most people use it to control 4 and have each channel switch an outlet on/off in an outlet box that's readily available at any hardware store. These are commonly referred to as "4 port SSR's."

If you decide to leave the SSR's on the controller board, you will not need control cables, but you will need an individual power cable for each channel. If you use extension cords, the cable cost can climb very fast. However, there is additional cost for outlet boxes/outlets if you go that route instead. The layout of your lights and the location of your computer and controllers will determine which system is better for you to use.