When I was in university, a local restaurant owner approached me about designing a marquee lighting system in his entrance stairwell. He wanted to attract and guide more customers to his business. He never did agree to the proposed price, but it planted a seed. Since that time, I have seen many marquee-based systems at places like local theaters or animated holiday displays.
So, I set out to design my own system based on the following parameters:
The end result is my system shown in the Figure 1 photos.
FIGURE 1a. Inside of the control unit.
FIGURE 1b. Close-up of the speed control portion of the circuit.
FIGURE 1c. Test button and power plugs.
FIGURE 1d. Circuit breaker bank.
FIGURE 1e. Outside display.
Note: The circuit board shown is a prototype that also does a two head traffic stop light feature (not included in this design).
Figure 2 is the schematic of the system.
FIGURE 2. System schematic.
Specifics and notes are as follows:
All components are through hole and mount onto one double-sided PCB measuring 5.4” long x 5.45” wide. The board mounts into a case using four standoff holes sized for 4-40 hardware. Figures 3a and 3b are the board layouts.
FIGURE 3a. PCB layout top view.
FIGURE 3b. PCB layout bottom view.
The suggested Parts List is for the overall system.
All the components are available from Digi-Key but you can substitute from other sources if convenient/required. You can use optional integrated circuit (IC) sockets for U2, U3, and U4, or you can directly solder them onto the board. U1 mounts to the board with 4-40 hardware.
The Parts List does not include external wiring past PL2, light sockets, lamps, or any supporting means. That’s all up to you and your creativity!
One thing to keep in mind is that the LED bulbs should be “instant on” with no power-up delay from the internal electronics for this system to work effectively.
Setup requires some planning on your part. You’ll want to sketch out a plan to determine how you want the lights to flash and then determine the number of bulbs required. My circuit uses 3W LED based light bulbs, and these bulbs are bright! They fit in a standard E26 incandescent light bulb socket.
My prototype used two multiple light bulb bathroom fixtures from a local building recycle store. The relays are capable of handling up to 2A, but I never load a circuit to more than 80% of its rating; 1.6A in this case. Then, the maximum number of 3W bulbs per channel is:
= (0.8 x maximum channel current) / (bulb power rating / 120 VAC)
= (0.8 x 2A) / (3W/bulb / 120 VAC)
= 1.6A / 0.025A/bulb
= 64 bulbs (or a total of 384 bulbs equally distributed over all six channels)
1. Use proper wiring. Stranded copper with a suitable insulated voltage rating is my go-to. Depending on the length of your runs, you may need to use #14 or #12 AWG wire to keep the voltage drop within values specified by your local electrical codes. This also prevents poor system operation. Some of the bulbs at the end of a circuit may not properly light or even light at all.
2. Use proper materials and components for all external connections and any wiring splices required in the circuit runs. This is not a job for masking/duct tape and thin speaker wire!
3. Wire the channels using color-coded wire to make wiring and troubleshooting easier. I recommend using the resistor color code in the following example:
Programming is easy. As mentioned before, J1 sets the number of channels, and P1 or P2 sets the flashing rate. Set J1 with the system unpowered. Adjust P1 or P2 to get the desired switching rate with power applied. Also disconnect the power to the unit before unplugging any loads or changing burned out bulbs. Safety first!
The first prototype test was at an indoor weekend flea market display. For 12 weeks, the display ran for seven hours every Saturday and Sunday. With a switching frequency of 0.5 seconds, each bulb endured over 1.2 million switching operations without any failures.
The second test was at my house and mounted on a front shed as part of a Christmas display. The flashing rate was identical to the flea market setup. The control box sat in the unheated shed in temperatures from -15°F to 40°F. I started the display on the afternoon of November 11 and ran the system 24/7 to January 1 (50 days straight with the exception of two brief power outages). Again, no bulb or system components failed after an estimated 8.6 million switching operations. Both tests used the same bulbs for an estimated total of 9.8 million switching operations.
This is the simple, reliable, and cost-effective circuit you need if you’re looking for:
I hope this circuit really brightens things up for you. NV
|Voltage Regulator, 15V, 1A
|Decade Synchronous Counter
|Eight-Channel Darlington Driver
|Green LED, 2.2V, 20 mA
|Bridge Rectifier, 200V, 1.5A
|Diode, 100V, 200 mA, DO35 Package
|SS1, SS2, SS3, SS4, SS5, SS6
|Mini SIP Solid-State Relay, SPST-NO, 2A, 24-480V
|1A, Single Pole Circuit Breaker
|CB2, CB3, CB4, CB5, CB6, CB7
|2A, Single Pole Circuit Breaker
|1.10K, 1%, 0.25W Resistor
|5.62K 1%, 0.25W Resistor
|3.32 K, 1%, 0.25W Resistor
|100K, 1%, 0.25W Resistor
|R5, R6, R7, R8, R9, R10
|499, 1%, 0.25W Resistor
|10K, 1%, 0.25W Resistor
|250K Multiturn Potentiometer
|250K Panel Mount Potentiometer with Locking Nut
|1 µF, 35V Tantalum Capacitor
|1000 µF, 35V Electrolytic Capacitor
|22 µF, 35V Electrolytic Capacitor
|0.01 µF, 50V Ceramic Capacitor
|Panel Mounted Momentarily Normally Open Pushbutton
|Conn Header Vertical 10-Position
|1.67’ NEMA 5-15P Cord
|SPST Toggle Switch, 15A, 125V
|120/240V: 15/30V, 2.5 VA Transformer
|8-Pin DIP Socket for U2
|16-Pin DIP Socket for U3
|18-Pin DIP Socket for U4
|4-40 x 0.5” Hex Aluminum Standoff
|RAF Electronic Hardware
|4-40 x 0.25” Stainless Steel Screw
|B&F Fastener Supply
|Internal Tooth Washer (for Standoffs)
|B&F Fastener Supply
|SCREW 9, SCREW 10
|4-40 x 0.50” Stainless Steel Screw (for U1 and Chassis Ground)
|B&F Fastener Supply
|4-40 Stainless Steel Nut
|#4 Flat Washer (for U1 and Chassis Ground)
|#4 Split Washer for U1 and Chassis Ground)
|8” x 8” x 4” Case
|Nylon Cable Gland - PG7 with 8207/8207.40 Nut
|Pins for SR1, SR2
|Pins for SO1
|Quick Connect Receptacle 14-16 AWG, 0.250” Wide
|Circular Ring Connector 16 -22 AWG, #4 Crimp
|#16 Stranded Copper Hookup Wire – Black
|#16 Stranded Copper Hookup Wire – Brown
|#16 Stranded Copper Hookup Wire – Red
|#16 Stranded Copper Hookup Wire – Orange
|#16 Stranded Copper Hookup Wire – Yellow
|#16 Stranded Copper Hookup Wire – Blue
|#16 Stranded Copper Hookup Wire – White
|Printed Circuit Board
What’s in the zip?
PCB Top and Bottom Layers