Bending the shaft slows the motor down via loading but still stirs up a storm. Try a short straight shaft at fairly high speed that just does tickle the water and adjust length or water level to get the desired stir rate. Try a 5 to 100ohm 1/2 amp pot in series with the motor instead of the 3 ohm resistor for a 1 1/2 volt power supply. They're hard to find under 1 K
If you're going to run it off 12 v, get a RShack 9 to 18v motor for about $3. Slowing a 1.5 to 3 v motor on a 12 v supply will suck up a lot of current in the resistance, heat things up to smoking in a hurry and just waste power. Ken At 03:22 AM 6/24/01 +0000, you wrote: >Hi from Joe: > >There are 3 ways you can slow it down. > >1. Change the shape of the stir shaft - 'Ole Bob' >recommended use of a #14 insulated house wire w a bend >of about 15 deg, about 1" from the wet end. I use 2 >bends, 1 about 20 deg., about 2" in & the next about 40 >deg. about 1.2" in, in the opposite direction. Attempt >to get a counterbalancing mass distribution so it >doesn't shake as much. It doubles or triples the >mechanical load [& pumping action] so it can be run >slower / more loading slows the motor. >Mine runs continuously for several days w an average of >5 Vdc applied & doesn't get warm enough to feel warm. > >2. Order a PWM circuit kit from All Electronics, >800 826 5432, EM-114, $3.50. Specs say 3 - 6 Vdc, .5 >A. My observation is that it can put up w a 12V supply >& deliver more than .5A since whenever the switch >transistor is on, it saturates & doesn't dissipate much >power. You would then operate it at about 30% duty >cycle for an average voltage of about 3.5 V. This would >get you full speed under full load. You're better off w >a 5Vdc supply instead, since they make about 7V at no >load - the kit transistor will last longer, but you >should hunt for 1 that will do a full amp. > >3. If you get a Triad FS10-1200 power transformer >[about $9 as I recall, an equiv. works] & build up your >own complete unit, you can do without any motor speed >control. I can't do a schematic here but this allows >quick solution making. This transformer has 4 coils - 2 >at 115 Vac & 2 at 5Vac, 1.2A. Pick terminals 1 & 2 to >apply 115Vac [thru a 1/2 A fuse], connect the other 3 in >series to make about 165 Vdc when 1 diode [1N4004] is >used for a rectifier. Use a filter capacitor of about >10 microfarads, 200Vdc to make the solution supply along >w a series resistor of 47K 1/2W which will limit the >current to a little under 4 mA. When I start a batch, I >get nearly 40 Vdc across the silver strips which drops >to about 10 Vdc in an hr. After 3 days it goes to 5.7 V. > >Use a full wave bridge rectifier across the lowest >voltage coil, about 220 microfarads at 10Vdc & connect >that directly to the motor, no controller. Will make an >avg of 5Vdc, lots of ripple, no motor nor transformer >heating. I used the controller there & found it liked >95% [full blast] so you should do fine with none. > >You can slow it some by reducing the filter cap, even >remove it to use an RMS equivalent of 6.1/1.7 = 3.59V or >by bending the stir shaft more. > > >This is my favorite since I don't have to mess w seeding >the DW or wait a long time for it to start. > >Bye. > > >-- >The silver-list is a moderated forum for discussion of colloidal silver. > >To join or quit silver-list or silver-digest send an e-mail message to: >[email protected] -or- [email protected] >with the word subscribe or unsubscribe in the SUBJECT line. > >To post, address your message to: [email protected] >Silver-list archive: http://escribe.com/health/thesilverlist/index.html >List maintainer: Mike Devour <[email protected]> > >
