View Full Version : Dumb RGB LED DC SSR h/w, just starting development

12-18-2015, 06:32 PM
Ok, a few years back I bought a bunch of the 5150-type RGB led strings and intended to use them then but time slipped by and I just got around to prototyping something I'll be using next Christmas.
First picture (controller1) shows a small controller, runs on 12VDC, available on ebay for under a buck apiece. The 2nd pic (controller2) is the backside of the thing showing the traces. On the left side of the pic is the connector to the string of leds. Top is +12VDC. To fire the strings, the bottom pins need to be grounded. These are controlled by the small mosfets which have a 1K resistor that runs to the unmarked IC. The mosfets inputs, when off, are at +5VDC, and grounded to fire. Since I only wanted one string at a time, these small mosfets are enough, no need to get a 10A version. The last pic shows what I did to the board, cut off the unmarked IC and the little controller ATMEL528 chip and put black insulation stuff on it. The SSR connector to the controller board runs on +5VDC and the outputs are grounded. However, I needed to connect the grounds together so that the +5 and +12 volts had a common reference. The blank unused SSR board that I had, didn't have pin 7 of the connector wired to anything (ground), so I ran a wire from pin 7 on the SSR board to the bottom connector, where the black wire and alligator clip is. Then I ran wires from the SSR board to each of the resistors shown where the arrows are. Last, the top pin is connected to 12V (other alligator clip). These connections were taken off for the picture, it looked really cluttered otherwise. NOTE that there is NO optoisolator chip involved here. Getting one would eliminate having to connect the grounds and increase the cost by a buck but honestly I didn't have a spare one to experiment with. My chore for the year is to figure out a good way to connect everything up for real, the dollar controller with three mosfets and the connector just seemed like something to try.