Power Sequencer

[andy11]

Just finished designing/prototyping a quick and dirty power sequencer for the home theater. Ended up costing about $40 vs $350 for the furman ps-8r. It has 4 switched outlets w/ a 5s delay between steps. The relays can handle 12A @ 120V which is more than enough for my small qsc amps. Just have to whip up a cheap rack-mount enclosure. Any ideas?

BTW I can post the schematic for anyone who's interested.

[hjames]

Just finished designing/prototyping a quick and dirty power sequencer for the home theater. Ended up costing about $40 vs $350 for the furman ps-8r. It has 4 switched outlets w/ a 5s delay between steps. The relays can handle 12A @ 120V which is more than enough for my small qsc amps. Just have to whip up a cheap rack-mount enclosure. Any ideas?

BTW I can post the schematic for anyone who's interested.

Yes, please - I'd appreciate seeing the schematic!

[grumpy]

ideas? indicators on the front (e.g., neon bulbs), outlets on the rear, MOV(s), circuit breaker, remote turn-on (12v signal), surplus chassis or rack shelf...

[andy11]

I've been looking around at enclosures on the internet and can't seem to find a single space chassis that's under $75. For a circuit that cost around $40 to make it almost seems like a waste of money. I also have only limited tools to work with (no bending break etc.) so bending metal will be pretty difficult. Just wondering if someone has come across anything in the $30-$40 range, or does something like that exist?

[andy11]

ideas? indicators on the front (e.g., neon bulbs), outlets on the rear, MOV(s), circuit breaker, remote turn-on (12v signal), surplus chassis or rack shelf...

I've got some panel mount LEDs and snap-in outlets for the rear... the remote turn-on and especially the circuit breaker are excellent ideas! Didn't see your comment about surplus chassis till i reread your post. Do you know of somewhere that would sell these?

[andy11]

ok here's the schematic: http://www.mts.net/~rohuly/sequencer.gif
I'll post the schematic for the relay board once I finish drawing it (tomorrow).

[UreiCollector]

Everyone,

Here is what I did for my theater. Parts included:

20amp outlets
110v coil dpdt relays
110v time delay blocks (ecg rly220) with the variable delay pot, but one with the external resistor to set will work well too
all the boxes, adapters, and emt to connect

I use the switched outlet from my audio processor to drive the relays, which have the delay blocks in series. I have set up 2 circuits for my amplifiers, and when the first relay kicks on, the first pair of outlets on each circuit turn on. When the second relay kicks on, it powers up the second outlet on each circuit. Basically I'm getting 2 delays per circuit. It works great, and was cheap, and simple. I just switch the hot, and leave ground, and neutral hard wired.

Good luck everyone.

[andy11]

Forgot to explain how the circuit works. Momentary pushbutton starts sequence on first button push. Switch is debounced so logic circuit doesn't get confused when contacts of switch bounce. Second half of J/K flip-flop is held high. Shift register starts shifting in 1's every 5.8 seconds which turn on the transistors which in turn activates the relays. When the button is depressed a second time the process is reversed. Second J/K goes low. Shift register changes direction and begins shifting in 0's. Relays are deactivated in reverse order.

The speed of the sequnce can be adjusted by substituting in different values of R7 and R8. The clock circuit could also be redrawn using a potentiometer to adjust speed. The values of the transistor input resistors must be recalculated depending on coil resistance of the relays, and also what type of logic will be used (cmos can source much more current than ttl). Solid state relays work extremely well for this application as they do not require a driver transistor. The downside is that they cost around $50 each! I paid 4 dollars for each of my relays.

I thought about a few different designs but I ended up choosing this one because it's very small, very cheap, portable (once it's in its rack chassis) and can easily be expanded to as many outputs as needed without taking up much extra space.

[Titanium Dome]

Mr. McGuire: I just want to say one word to you - just one word.
Ben: Yes sir.
Mr. McGuire: Are you listening?
Ben: Yes I am.
Mr. McGuire: 'Plastics.'

http://www.polycase.com/shop-by/appl...neral-use.html

If those aren't big enough, then how about genuine Lansing enclosures?

http://www.lansing-enclosures.com/

[andresohc]

I may have a nice used unit you can have for $20 plus shipping. PM me. Andre

[andy11]

Awesome idea... didn't think of that!

Mr. McGuire: I just want to say one word to you - just one word.
Ben: Yes sir.
Mr. McGuire: Are you listening?
Ben: Yes I am.
Mr. McGuire: 'Plastics.'

http://www.polycase.com/shop-by/appl...neral-use.html

If those aren't big enough, then how about genuine Lansing enclosures?

http://www.lansing-enclosures.com/