I bread boarded w/o the transistor and it only detects the IR from a tv remote.
back to the drawing board and include the transistor.
hopefully using say a .01 cap in series with the 10 ohm will work without any problems. locating a 047 electrolytic cap now is kinda outa the question. running outta money (need to get reimbursed from scout funds) but need pcboard etc by tomorrow night.
0.047uF is a 47nF film or 473 ceramic capacitor, not an electrolytic.
The 0.1uF and 100uF capacitors across the battery are important when the battery is not new.
I purchased a surplus bag of caps from Radio shack. have lots of 2.2 4.? etc. that I used for the 555 organ project. hopefully got something that should suffice.
got board designed and will etch and assemble one in the morning.
going with the transistor/lm386 schematic..
Last two years was a 7 key organ using a resistor ladder and several odd caps throw in a 555.
Purpose is that this particular device can be used to amplify sound thus come summer, we will connect a dish antenna with mic. Demonstrate versatility.
Hardest part is teaching how to solder without lifting board traces.
Traces are lifted when the soldering iron tip is too hot. Then the rosin burns away instantly and the glue on the traces is vapourized.
All my career I used Weller temperature controlled soldering irons that last forever and work extremely well.
My personal Weller temperature controlled soldering iron is about 46 years old and is still made and sold. Its tip is 10 or 20 years old and still works like new because it is NEVER too hot.
Traces are lifted when the soldering iron tip is too hot. Then the rosin burns away instantly and the glue on the traces is vapourized.
All my career I used Weller temperature controlled soldering irons that last forever and work extremely well.
My personal Weller temperature controlled soldering iron is about 46 years old and is still made and sold. Its tip is 10 or 20 years old and still works like new because it is NEVER too hot.
I had a Komec 936 whic is a Hakko knock off. Have a working pic controlled soldering iron that I need to tweek to get it working perfect. Just the code needs some work.
Iron has auto shut off, leds to indicate when its warming and an LCD readout (desired temp and tip temp)
uses a Hakko iron for the actual soldering tip holder.
uses an RTL sensor
As for the scout project-it went bust as far as the boards I was etching. All I had were some 2oz boards that take forever to etch and the printed pattern started comming off (if I use the thin 1/2oz boards no problem)
going to redesign a board and have Itead Studios make them. 10 boards for $10 http://iteadstudio.com/store/index.php?main_page=index&cPath=19_20
just have to be 5cm x 5cm. shouldn't be a problem doing 2x boards. even have hopefully room for a switch.
BUT the scouts have to figure out what is wrong with pic compared to schematic
We call it "LEARN BY DOING"
compare pics to schematic. the one has the pot connected wrong
I received the boards from Itead, assembled one board, found one trace in wrong place (my fault). corrected finished assembly but it dosn't work.
The unit I had using the 741 worked on the breadboard but went with transistor.
Well something is wrong perhaps the 1uf going to the base. I get only 640mv and collector shows 2-3v so transistor is not ON.
Contemplating shorting out the 1uf to see what transpires.
I removed the LM386 just to measure thinking maybe it has an effect = no
Doubled checked the 2n222 data sheet as well as the photo transistor.
Going to have new boards made with corrections BUT if this design won't work!!
Need to look at what voltage is being fed to the 10k pot/LM386 pin 3.
I measured but not recalling what it was.
Could be the LM386 needs more gain?
And I failed to insert the 10 ohm/cap on the pin5 output but should still hear something?
When I used the 741 op amp circuit I got some sound without the 10ohm/cap on pin 5. Chip got warm.
Note #2 in the project says that the 1uF capacitor must be non-polarized (film or ceramic), not an electrolytic.
The circuit will work but without low audio frequencies if a 0.22uF or 0.33uF capacitor is used instead of 1uF.
Maybe the bag of capacitors you bought has some 224 or 334 capacitors.
The circuit is designed with low gain to pickup CRT screens and remote controls. If you want to hear a modulated light beam then maybe add a 10uF capacitor between pin 1 and pin 8 of the LM386 to increase its gain 10 times.
EDIT:
Pin 2 and pin 3 of an LM386 are both 0VDC.
The gain of the LM386 in your project is only 20. the gain is increased to 200 if a 10uF capacitor is added between pin 1 and pin 8.
The LM386 will probably oscillate at a high frequency if the 10 ohm resistor in series with a 47nF capacitor at the output are missing then it will not amplify sounds.
The 1uf cap is a new on I purchased from Jameco it say 105 https://www.jameco.com/webapp/wcs/s...NOopQ==&ddkey=https:StoreCatalogDrillDownView
its non polarized.
I am thinking maybe because I am using a floriscent light above my bench for light source?
The circuit with the 741 worked using same.
Going to try a remote control. If not then insert the 10uf between pins 1 & 8
time to re re design the pcboard.
y plan is to sell kits in October at the University of Scouting held in Blackfoot Idah each year (put together a worksheet etc to meet all the merit badge requirements for electronics.
Along wit this perhaps an alternating LED kit using a 555.
Putting a 10uf between 1 & 8 AND using a remote control I can hear very faintly the output.
NO where near the volume using the LM741
Now I am perplexed on what to do. New chips etc.
Don't really want to go back to the 741 (cost of kit will go up)
Something really wrong with circuit?