You may connect the power and ground connections from the DC power supply anytime but DON'T PLUG IN BOARD DURING ASSEMBLY!
Note: When putting on the chips exact row positions don't really
matter, just as long as the chips go in the order specified and are "down
the middle" of board, with lettering READABLE FROM THE GROUND SIDE.
Install all the chips [refer to previous picture]:
Chip#1 is the 555 timer chip.
Chip#2 = 4020B counter chip.
Chip#3 = another 4020B chip.
Chip#4 = 4013BF dual D-type Flip Flop.
Note: We will only use one side of the "dual" F.F. I used a dual because it was available (and commonly found).
Wiring bottom chips
Note how pin8 on Chip#3 got its ground connection from a different row. You can get Power or Ground connections (respectively) from anywhere on the outer pin columns.
Note the optional LED's. The green taps into pin1 on chip#4. This LED will show when the timer is ON (helps check things). The Green LED's other leg plugs into the Ground (as shown). The Red LED will indicate when the timer is in the OFF state. It taps pin2 of Chip#4, and also needs to be grounded (as shown).
NOTE: Make sure the LED's you use have built in resistors, or else add a little resistance in series with each LED.
The Relay
Now that the logic portion of the timer is done. Go ahead and plug the DC Power supply block into the wall. The green and red LED's should alternate 2 seconds green, 2 seconds red. This is the troubleshooting setting (we will adjust ON/OFF times later).
Connecting the relay:
The Solid State relay has two ends, the DC control end, and the AC power end.
***Caution*** AC current can kill you, so please be careful. Make sure the power strip is UNPLUGGED.
We begin by slicing through the outer plastic of the Power Strip's insulation, about a foot or so from the plug. Peel back the insulation to reveal three wires (white, green, and black). The black one is the POWER wire, the one we will splice into the AC side of the relay. Cut the black wire and cut and peel back some insulation from each cut end. Make a small loop on each cut end, and screw down these loops under the relay's screws (AC end). [See picture for details]
Connect two small (8-12") pieces of wire [see parts list] to the Relay's DC
power and ground screws.
Tape up the entire relay (especially the AC end) with black electrical tape (or duct tape). This will prevent any contact shorts and improve safety.
Plug in the Negative (black) and Positive (red) wires from the relay to where the GREEN LED was before (as shown). Note that I have soldered the ends of these wires to pieces of jumper wires (again, for more rigid connections).
Note that I have replaced two key wires from previous pictures with the YELLOW and GREEN wires (for clarity). Leave these wires connected at chip #4.
To Set ON/OFF times:
Chip #3 controls OFF time.
Chip #2 controls ON time.
To change these times, simply plug the Yellow or Green wires into other pins (on Chips 2 and 3) as follows:
The following times are valid for chip 2 (ON time) and chip 3 (OFF time):
| Pin # | Schematic Pin | Delay Time |
| | | |
| 9 | Q1 | 2 sec |
| 7 | Q4 | 16 sec |
| 5 | Q5 | 32 sec |
| 4 | Q6 | ~ 1 min |
| 6 | Q7 | ~2 min |
| 13 | Q8 | ~ 4 min |
| 12 | Q9 | ~ 8 min |
| 14 | Q10 | ~ 17 min |
| 15 | Q11 | ~34 min |
| 1 | Q12 | ~ 68 min |
| 2 | Q13 | ~ 2 hr 15 min |
| 3 | Q14 | ~4 hr 30 min |
***Remember that the pins are numbered from 1-16 and arranged counter clockwise from bottom left of chip. Do not plug into any other pins besides those listed in table above!***
Sample time setting:
To set 64 sec. ON / 256 sec. OFF, plug the Yellow wire at chip #2 into pin#4, plug the Green wire at chip #3 into pin#13.
The board and relay could be fastened inside of a small plastic case with holes cut for the power strip cord ends. Make sure to keep components from touching though. Simply plug in your appliance into a spot on the power strip, plug in the strip and DC power supply, and set the ON/OFF times.
Here's the schematic of the completed cyclestat.
Be sure to add a filter capacitor as the schematic indicates (not shown in photos) to ensure proper timer functioning.
TIMER IMPROVEMENT
Below is the updated timer layout, featuring an "automatic on" function that restarts the timer in the ON position when power is applied. The resistance/capacitance values on the RC circuit are subject to what works. (The stated values worked for me, It's all about resetting the chips for long enough time intervals when power up occurs -- play around to find what works best for your timer.)
Shown Values:
Res. at bottom (added RC circuit) = 1K ohm
Res at middle = 10K ohm
Cap. at bottom (RC circuit) 68 uF.
