Tech Forum Questions

A schematic along with the pot resistance would have been helpful, but here are some things to try.

The problem is too much voltage across the pot. The large voltage change at the wiper as you turn the shaft a few degrees makes it hard to fine-tune. If the pot is not connected to a low impedance source such as a power supply or battery, put a resistor across the end terminals to reduce the voltage across it. Try a resistor about 20% of the pot resistance.

This will help you fine-tune, but now the voltage range at the wiper may not be right for your circuit. In that case, or if the pot is fed from a low impedance source, connect resistors from each end terminal to the wiper instead of putting a resistor across it. Keep the sum of the resistors about 20% of the pot resistance, and try various combinations of resistor values until you get the required range.

I would expect that removing the photo diode would keep the alarm from activating, but it's impossible to guess the internal circuit configuration. Try temporarily shorting the diode with a clip lead. If that doesn't awaken the birdie at night, remove the diode.

Might not work by removing the photodiode.

What might help is to check the voltage drop over the photodiode with the lights on, and replace it with a resistor to give the same voltage drop across it.

Using a 100k potentiometer, turn it on the max resistance (100k) and slowly decrease the resistance until the same voltage is read as the original voltage drop across the photodiode. Measure the resistance – and replace with a fixed resistor of the appropriate value.

from: www.reliance.com/mtr/mtrthrmn.htm  Basic Motor Theory

Interpoles
Interpoles are similar to the main field poles and located on the yoke between the main field poles. They have windings in series with the armature winding. Interpoles have the function of reducing the armature reaction effect in the commutating zone. They eliminate the need to shift the brush assembly.

If the program does not require a response from the puppets, you could try connecting the serial output of the computer to a modem (RS-232 connection) and recording the modem output (telephone line) on an audio CD.  Then connect the modem (RS-232) to the puppets and the modem (telephone line) to the audio CD output.

You may need an amplifier between the CD output and the modem to get a high enough signal to the modem. You might have to change some dip switches in the modem or change some of its settings from the computer such as: don't wait for dial tone; go off hook. You might end up needing a microcontroller between the modem and the puppets to control the modem - like a PIC chip, Basic Stamp, or PicAxe.

Download the free Microchip IDE from: www.microchip.com/mplabx-ide-windows-installer which is a free, full feature download of the Interactive Development Environment. More info about the IDE and its features at: www.microchip.com/pagehandler/en-us/family/mplabx/ where there are also C language downloads - though I don't know if all the C downloads are free.

Purchase a programmer board such as one of the following from  www.ramseyelectronics.com/ 
www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=CK1301 for $34.95 - with this one you will have to program your PIC chip with the ICSP (In Circuit Serial Programming)  connector.

www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=K8076 "Note: This product requires a standard RS232 serial connection and is NOT compatible with USB to RS232 serial adapters or converters." for $47.95   It also has an ICSP (In Circuit Serial Programming) connector for programming PIC chips that are soldered to a PCB. This can be a way to program PIC chips that are other than a DIP (Dual In-line Package).

www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=UK1300 for $69.95 This one connects to your PC with a USB cable.
The datasheet for the PIC16F876 is at:  ww1.microchip.com/downloads/en/devicedoc/30292c.pdf

Here is one method that I think will work for you, but I don't know how it will handle control characters. It's fairly quick to set up, though.

On XP:

- click Start
- point to Settings, then click on Printers and Faxes
- double-click on Add Printer
- click on Next
- click on Local Printer
- select Local Printer Attached to this Computer
- click on Next
- let it search, it will come up with "The Wizard was unable ..."
- click on Next
- select the LPT port you want to use
- click on Next
- from the left column, select Generic
- then from the right column, select Generic / Text Only
- click on Next
- if you desire, change the printer name
- select whether or not you want this to be the default printer
- click on Next
- select whether or not you want to share this printer on your network
- select No for printing a test page

It will now show you your selections.
If it looks ok, select finish.

It will show that it's copying some files and then the window will disappear indicating that it is complete.

To cause Windows to NOT spool the printer output:
- Right click on the printer you just created
- click on the advanced tab
- select Print directly to printer
- click Apply, click OK
 
(The following code is from a VB6 app that I wrote that was using an HP printer with an HP driver.)

In VB there is a Printer object.
'It needs some setup code:

'Printer defaults
   With Printer
        ColorMode = vbPRCMMonochrome
       .Copies = 1
       .Orientation = vbPRORPortrait
       .Zoom = 100
       .ScaleMode = vbTwips
       .FontBold = False
       .FontItalic = False
       .FontStrikethru = False
       .FontTransparent = True
       .FontUnderline = False
       .FontName = "Courier New"  'not proportional letters
       .Orientation = vbPRORPortrait
       .ScaleMode = vbInches
       .FontItalic = False
       .FontBold = False

'You may not need the following:
.FontSize =  

If .PaperSize <> 1 And .PaperSize <> 9 Then
.PaperSize = 1
End If

'sets top, left of page
Printer.CurrentY = 0
Printer.CurrentX = 0

'end of May Not Need

' Here's where you actually print the text"
Printer.Print strStringOfText

' note: If you want to print more on the same line,
' add a trailing semicolon for all but the last print

Printer.Print strStringOfText;

Printer.NewPage    'ie: formfeed

'If your printer is spooling, the following will cause the document to print.
'It will also signal End of Document so you can start the next document
Printer.EndDoc

He might refer to the June 2011 issue of Nuts & Volts and the article on the "Bat Detector" by Jonathan Berber.  Using this concept, a hetrodyne circuit, utilizing a piezo transducer (microphone), should result in an audible, to human ears, signal.

One easy approach is the digital divide circuits used in Bat detectors. For example: http://pw1.netcom.com/~t-rex/BatDetector.html

Basically it just divides the input frequency by some power of two (2,4,8,19, ...). In this case divide 0 to 40KHz by 4 and get 0 to 10KHz. The digital divide circuit is pretty simple but you will lose all amplitude information. Given how simple the circuit is that might be acceptable.

A suitable microphone will be a bit of a problem. Many mics will give a signal at frequency up into the 40KHz range but the sensitivity will drop off a fair amount. Piezo transducers are often used for Bat calls and they'll give some signal up to, perhaps as high as, 100KHz. But piezo have resonant frequencies and they'll be super sensitive near that frequency. A typical 1" diameter thin piezo resonates at about 3KHz.

There are ultrasonic transducers designed for 40KHz that work well as a mic at that frequency, but their sensitivity at lower frequencies drops off.

First of all, try to avoid the term "HHO" it makes you look like a crackpot. Electrolysis of water produces a mixture of molecular hydrogen (H2) and molecular Oxygen (O2) in a 2:1 ratio, there is no such thing as "HHO".

Second thing to know, is that no matter what you do, the energy into the system is more than the energy you get back out of the system. If you put in one Joule of energy to break the water into H2 and O2 you will get back less than one Joule when the H2 and O2 is recombined. That's the laws of thermodynamics and you can't break those laws.

Now, what are you really trying to do? You mention a Tesla coil but that is a high voltage low current system. Electrolysis cells are intrinsically low voltage high current devices. To electrolyze water you only need about 2 volts per cell. Using higher voltages doesn't accomplish anything useful, indeed higher voltages just mean that you will get electrolysis reactions you don't want as well as significant energy loss due to ohmic heating. So it would be really silly to take an energy source and use that to run a Tesla coil then use that output to run the electrolysis rig. If you are thinking of using the Tesla coil to pull power out of say… atmospheric RF (basically using the coil as an RF antenna), then you have to go back to my earlier point about energy in > energy out.  How much "free" energy can the coil actually capture from the atmosphere? RF waves are extremely low energy; even with a big antenna you are not going to be able to capture enough energy to light even a single LED.  So, running an electrolysis cell might be possible but it isn't going to generate enough fuel to make it worthwhile.

One last thing, H2 + O2 is explosive. The Hindenburg didn't explode, it combusted. A mixture of H2 + O2 WILL explode, and that explosion will be much more energetic than what occurred with the Hindenburg. Add in the worry that any electrolysis cell produces gases that can be compressed along with heat and you have two pathways to an explosion: combustion and over pressurization of the H2 + O2 storage tank.

I would try using either one or two LM386s in low gain low noise configuration, depending on if you're using mono or stereo headphones. Look at the Data Sheets at: www.nari.ee.ethz.ch/wireless/education/PPS/PPS02/doc/LM386.pdf and page down to page 5. The very first schematic is for the amp used without the 10µf cap between pins 8 & 1 which limit the gain to 20 & the noise is greatly reduced as well.

Also, I noticed that Russell Kincaid had a similar question in the same issue, page 24 and his answer was given in Figure 7, which seems to be missing from my paper magazine, perhaps he'd be kind enough to send it to you directly? (Ed: Figure 7 can be downloaded from the link on this page {filedir_8}index.php?/magazine/article/august2012)

I also found a link to a solution (with a problem of high hissing noise) for the same application on-line at: www.edaboard.com/thread232457.html  He ended up saying "Now I am able to reduce the hiss type noise at the output by just removing the 10mf cap between pins 1 and 8. There is still a little bit of hiss noise at the output but for me that is ok." Which is then the configuration I mentioned above in the Data Sheets.

A LM386 based circuit would be simple and will run from a 9V battery. See http://web.mit.edu/6.s28/www/schematics/lm386.htm

You can also buy a small kit such as at www.electronics123.com/kits-and-modules/audio-amplifier-1W-LM386-kit.html

If the output sounds to harsh, drop the gain by removing the feedback cap (C1 in the diagram at the first link).

While I haven't heard of the "RF Chip" you refer to, I have seen a great many miracle gadgets over the years claiming to increase your fuel economy. All of them of course come with grand claims and glowing testimonials, but invariably the only thing they do well is extract money from your wallet. There is only so much energy in a gallon of fuel and modern engines do very well at burning fuel efficiently and extracting as much of that energy as possible. The inherent inefficiency in an internal combustion engine comes mostly from the process of turning heat into mechanical motion, not inefficient creation of heat from fuel. You can't argue with the laws of physics.