Here is the board file with just the traces showing. I seperated the high voltage 110AC portion from the low voltage 12v circuit. This design uses the power from the wall outlet to power the circuit...no batteries to wear out.
I used one heavy duty outlet for the pump to plug into, I will plug my return pump into this. I also used a power IN recepticle
like is on a computer power supply, so I could use one of my many extra computer plugs as it's cord.
This is a picture of the circuit being designed on a breadboard. For anyone thinking of doing this I highly recommend breadboarding
out the 12 volt portion of the circuit and using an LED as a load to test and make sure you have the delay you want with the R1 and C1
values you choose. DO NOT BREADBOARD THE 110V AC PORTION!!!! ONCE AGAIN I TAKE ABSOLUTELY NO RESPONSIBILITY FOR ANYTHING THAT HAPPENS TO YOU
OR YOUR POSSESIONS IF YOU CHOOSE TO BUILD THIS DESIGN!
Something that MUST be stressed is that you MUST use a relay that will support the AMPS of whatever pump you plug into the outlet on the device. I
am using an Iwaki MD70RLT, which is 2.8 amps. I used a 5 amp 230v AC capable relay...we'll see what the longevity is once my tank is here.
After desigining and testing the circuit, I laid it out with a program called EAGLE made by cadsoft. It is a great FREE tool for circuit design and layout,
and can be downloaded HERE. If you DO choose to etch this circuit and use my parts list and layout,
the only way to ensure a proper sized circuit board is to USE EAGLE TO PRINT THE TEMPLATE!
Here is a picture of the etching setup...many,many sites out there to tell you how to do this. I will just say I use a positive photoresist method, print out the board layout on an overhead transparency, expose the board with UV light, and etch with Sodium Persulfate etchant in the little green tank with the aquarium air pump for agitation and a small aquarium heater to heat the etchant to speed etching.
