View Full Version : My first project....what did I do worng?

12-15-2013, 03:43 PM
First of all, I'd like to say, "thanks to all the members here for such a great resource." I've been lurking, and reading a lot recently and decided to start small with my first project. The goal was to make a blinky flashy wreath to hang on my door at work, for our holiday door decorating contest.

My Project's Specs:
3 channels (on/off, no dimming)
SSR Controlled
Parallel Port Direct Connect
Sequenced in Vixen 2
Each SSR driving one strand of single color lights.

The hardware:
on old PC with parallel port
SainSmart 4 channel 5v SSR (manufacturer's product page (http://www.sainsmart.com/sainsmart-4-channel-5v-solid-state-relay-module-board-omron-ssr-avr-dsp-arduino.html))
100 light white strand
100 light red strand
50 light green

What I did:
I dug an old mother board and power supply out of my closet, booted up XP, and installed vixen and the basic parallel plugin.
I stripped back the parallel cable and connected pin 2 (pink/white) to IN1 on the board.
I connected pin 25 (white) to the GND on the board.
The relay board needed 5v 165mA, so I used a +5V (red) from the PC power supply, as well as a ground, and connected them to their respective connectors on the board.
Since the board had test LEDs I didnt connect any of the lights to the switched side.

At this point the power light on the board was on, so I opened my sequence in vixen and ran it....
The Lights on the board flashed a few times (woo hoo!!)
Then, poof! The Magic smoke escaped from the relay board :(

So here I am with a week before Christmas releasing I'm probably going to have to wait until next year and give it another shot. I know you guys may not know much about that SainSmart board, but it seems like you're all pretty good with this.

SO, What did I do wrong?


12-15-2013, 10:56 PM
My best guess is you put 12V into the relay board from the PC power supply (seems to me there is 12V and 5V sources). I can't think of any other reason it would fry...

12-16-2013, 09:23 PM
Thanks Derek that sounds logical. To my knowledge there are 5v and 12v rails. I according to the internet the red is 5v and the yellow is 12v. But I guess I'll have to check with my voltmeter.

Is there a limit to how fast an SSR will switch? Could i have driven it too fast? I left the resolution in vixen to its default 100mS.

12-17-2013, 05:35 PM
A solid state relay works at line speed for 60hz you can switch every 8.3ms. Most likely, speed was not the issue. You needed to check the signal voltages going to the SSR. The parallel port outputs are tied to pullup resistors. If these outputs went to high, your SSR can smoke. This is just one guess at what could have gone wrong.