Power Sequencer

This project applies AC power to several different devices in sequence.

If you don't want to make your own, we list some commercial power sequencers.

What Good Is It?
Overall Design
Schematic

What Good Is It?

In September of 2003, I found an interesting product at Michaels. It was a set of lights built into plastic "footsteps". You put them on the ground, and they light up in sequence, as if a ghost or an invisible creature were walking across the ground, leaving glowing footsteps.

[photo]

The only problem was that a set only included 6 footsteps, and as soon as the last step went out, the first one would light again. This implied a monster that wasn't walking very far, and went around in circles a lot.

In order to make this gadget really good, it needs a sequencer that:

controls several sets of glowing footsteps, running each 6-step stretch in sequence
does nothing for a while at the end of the sequence, so the monster can take a rest

There is a ray of sunshine: Whever you apply power to the glowing feet, they start by lighting the first step. So we don't need to hack into the guts of existing glowing feet. We just need to sequence the 110 VAC power going into the feet.

Overall Design

The ideal form of this project is a power strip. It looks like a power strip. You plug numerous things into it like a power strip. But it's smart.

Unfortunately, the solid state relays that I had kicking around in my spare parts box were a little large. That means my implementation looks more like a power strip with a wart on the side.

If you are actually willing to pay money for components, I have seen solid state relays the size of power-tab transistors. With those, you could indeed fit the entire project inside a power strip.

Note: An entire cycle of the glowing steps takes about 10 seconds. So we want our power sequencer to clock at this rate.

Schematic

This project uses line voltage. Proceed with caution!

The schematic shows a single controlled outlet. You will have to replicate the SSR/socket part for as many channels as you wish to control. My setup uses four channels, so it can control four sets of glowing feet (0-3 outputs of the 4017). The 4017 continues to count past the used outputs, and the time spent counting up to 9 serves as a dark time - the ghost or invisible creature is taking a rest.

This circuit has been tested. It uses a battery to power the logic.

[schematic]

I am still in the process of building a version that takes its power from the 110 VAC line, and haven't tested it yet. I'll post the circuit when it is ready.

Thank you for visiting. Your comments are welcome.
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