Ok, I'm back. :) Keeping in mind that I'm really bad at this, here is a "draft" of the modified circuit: http://www.400gt.com/technical/misc/circuit2.jpg I...
Hummm...already I see a problem. There's no way +12v will go straight to the speaker. oops. But anyway, maybe you can point out what I need to change to get...
You have the speaker wrong. Connect the top of the speaker to the negative side of the 1000uF capacitor and not to +12. Connect the bottom of the speaker to...
I have invented a new energy source whereby heat is converted directly into electrical power. The heat is absorbed from background air or water that is of...
Thanks Charles, it's starting to make sense. I think next step is for me to breadboard it. I have a feeling some of those resistors will need to be power ...
Hi Charles, I finally got around to building the circuit: http://www.playerviolin.com/misc/speaker_driver/speaker_driver.htm Unfortunately, nothing much...
You might want to add a resistor in series with the frequency pot, maybe a 100k or so. Also, some of those prototyping boards split the power strips right in...
Got it running Charles! And it works great. I forgot to tell you something very important, which would have clued you in to the problem (because I forgot...
I think that wire is OK! Something else must be wrong. Perhaps one of the transistors is shorted or the wrong type. ... myself ... wire ... concerned. ... ...
Thanks Charles -- that makes a huge difference! Now the circuit is really hammering the speaker even with the battery. I'm goign to play around with values...
I think I would just let the circuit run "full blast" and control the volume by adding a low value potentiometer, maybe 25 ohms, at the speaker (one end to amp...
Thanks Charles. I've been playing around with the circuit and it works great. I hooked up an oscilliscope and have been watching all the "inverting" pulses....
Oh, one more question. The positive/negative pulses are of unequal duration throughout the system (viewed with my oscilloscope). Sometimes the positive...
I imagine the voltage limits the power output into a 4 ohm load and 12 volts would probably give about 25 watts or so. At some point the base drive will become...
That's odd. Notice the diode and resistor in series around the first gate of the original phone ringer circuit. That diode lowers the feedback value for one...
It worked! I put the diode and resistor (pot) in series like you said and was able to dial it in to an even +/- pulse -- much more power. :) In fact, I had...
That part is fine. I was confused with HC logic which is available with a lower voltage threshold for use with older TTL and that might explain the duty cycle....
hello , im the new guy , good day to all, now for my silly science and electronic stuff Sometimes i go drinking at er..um the strip club till late night. I go...
Sounds more like "impaired science"! : ) Anyway, maybe there are some other explanations. Maybe they just know where they are going and they don't hang out in...
At 04:29 PM 11/25/2005, you wrote: Charles, I have modeled your ion chamber bias power supply in LTSpice. In simulation - it doesn't get above 32 volts. I can...
Well, I don't know. I'll go measure it right now to make sure... I measure 46 volts with a 1000 megohm load and it was creeping up. I have a fresh battery...
I found a mistake. I left out a diode between the last stage and the 4uF filter. The last diode and the 10nF should connect together and then pass through...
I just made the change. Thanks again, Charles ... From: techlibdotcom@yahoogroups.com [mailto:techlibdotcom@yahoogroups.com] On Behalf Of Eric Vogel Sent:...
The mistake was worse than just a missing section. Try removing the top, right 10nF on your simulation and your voltage will go from 32 to over 40! That...
