My Notes

The wavemaker circuit is based on the 555 timer, which is really a basic building block for anyone who does DIY electronics. There are about 20 different companies which make a 555 compatible timer, so feel free to buy which ever one you can find. You can also use the 556 timer, which is a dual version of the 555.

For those who know nothing about electronics, Radio Shack sells an excellent book on the 555 chip and it contains a lot of different projects. This wavemaker circuit is just an alternating square wave circuit with an adjustable time between pulses. The most complex part of the circuit is coupling the 120V AC in to the 5V DC circuit. Fortunately, Bill Potter has taken care of that (thanks Bill!).

One final note, the 555 time can be run from 5 to 12 volts (usually), so you can run it from any household transformer you might have laying around that outputs voltage in that range. Walkman voltage converters work well.

A couple of notes from John Williams (Thanks John!)

> Newsgroups: rec.aquaria.marine.reefs
> Subject: DIY Wavemaker
> Date: Sat, 08 Feb 1997 23:13:54 GMT
> 
> While the euphoria lasts and the information is fresh in my mind, I
> thought I would post several points about building the wavemaker
> circuit found on Thomas Sasala's site: 
> 
> (http://home.dn.net/~sasala/fish/electronic/wave.gif)
> 
> I would first like to also say thanks to Thomas for providing this,
> and to the designer (Bill Potter?).  An especially big thanks to
> Warren for answering more questions then I had any right to ask.
> 
> Prior to this, I had no experience in electronics.  If you have never
> done anything like this, take heart.  It is very possible.  To get my
> feet wet I stole an old Heathkit self study course on direct current
> (DC) electronics from my brother-in-law, and purchased a book from
> Radio Shack (RS) that was more up to date and told about alternating
> current (AC) components.  I'm still alive and the house hasn't burned
> down, so the info helped!
> 
> Next, I took the circuit down and bugged the local RS.  I live
> rurally, so they had to order some parts.  Also, there were some parts
> that they did not know the RS substitute for.  Warren recommended
> Digikey (http://www.digikey.com/).  Thomas also has a list of parts
> with order numbers on his page.  This was a big help, and I would
> recommend that you use Digikey if you have any difficulty getting the
> parts locally.  They are also _very_ inexpensive (compared the the
> local RS on some components).  If I had to do it over again, I would
> have ordered two of each component from Digikey and built two
> wavemakers.  This is because they have a $5 fee for orders less then
> $25.  The sales and technical people at Digikey are very helpful and
> friendly, 1-800-344-4539.
> 
> To hold the circuit, I purchased a 2"x3"x6" plastic project box
> (#270-223) from RS.  I cut a hole in the top and installed a wall
> outlet and cover, just like the ones in the wall, purchased from the
> local hardware store (HS) (this is what I plug the powerheads into).
> I cut a hole in the end, installed a grommet, and pushed an extension
> cord with the end cut off through the grommet to provide power.
> 
> From RS, I purchased a small circuit board (#276-168).  I wanted to
> secure this in the box, so I purchased 4 nylon screws with nuts from
> the HS and epoxied them into the bottom of the box.  The circuit board
> fits down over the screws (there were holes in the corners of the
> circuit board that I enlarged slightly) and then the nuts are placed
> on the screws to hold it in place.  I also attatched the transformer
> to the box in the same way (see below).
> 
> A really big tip that came from Warren was to initially provide the DC
> power with batteries.  I soldered 4 AAA batteries in series, and found
> this to be the best way to initially power and test the DC side of the
> circuit.  Don't worry if the batteries have more then 5V, the timer
> chip (U5) is made to handle up to 15V.
> 
> Copying Warren, I used a micropot (a tiny potentiometer that fits on
> the circuit board) for R12.  The 100KOhm micropot I used provides 0-20
> second surges.  See Warren's note archived on Jeff Pfhol's site
> (http://nucalf.physics.fsu.edu/pfohl/) on how to increase the surge
> length should you desire.
> 
> When you get far enough along to test the TRIACs, use a load such as a
> 60 watt light bulb.  I was using my voltmeter and a small LED designed
> for testing a wall outlet initially.  Apparently the TRIACs have just
> enough leakage to show on the voltmeter and the LED.  This made me
> think that the outlets were always on, rather then alternating as
> designed.  Once I tested them by plugging a lamp into the outlet, I
> found they were working fine.
> 
> Back to the DC power supply.  The first several transformers I tried
> were rejects from old tape recorders.  Both were ineffective (test
> first with the batteries and avoid the frustration I had with this),
> either due to the current still alternating some or the current being
> to small.  Eventually, I built a DC power supply into the box to avoid
> this problem.  I purchased a 6V, 0.6A transformer from RS.  To the
> output, I attatched a full-wave bridge rectifier, a 470uF smoothing
> capacitor (if you do use an old transformer, you may want to make this
> large (1000uF) to help reduce any AC that might be left), and 5 volt
> regulator.  These parts are all on the circuit board or in the box
> (the transformer sits alongside the board).  This is kind of nice,
> because the box only has one plug to plug in.
> 
> There were also many small problems I had to work through, so if you
> have other questions let me know.  I'll answer what I can.  BTW,
> probably stating the obvious, but be cautious when working with the AC
> power!
> 
> You may want to suspend the finished wavemaker above the tank in a
> cloth hammock.  That way when it catches on fire it will burn through,
> fall into the tank, and put itself out. . .  Yes, I'm kidding!
> 
> One last point.  I have a Maxijet 1000 and an Aqua Clear 402 on the
> tank.  The 402 chatters when it turns both on and off.  The Maxijet,
> OTOH, is totally silent!  YMMV.
> 
> Have fun!
> 
> Pizarro  B->       (John W. Williams)
> 
> ***Opinions expressed herein are my employer's and may not represent
those of my own***