audio circuit capacitor size

mikea

I found this audio circuit in an obex wave player object. Is the capacitor value going to left out/right out speaker 1 microfarad?

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Audio Circuit:
//
//                  100OHM    1UF
// Left Pin Number  --R-------C-- Left Out (Use better audio circuit filtering for noise issues).
//                        |
//                        C 10NF
//                        |
//                       GND
//
//                  100OHM    1UF
// Right Pin Number --R-------C-- Right Out (Use better audio circuit filtering for noise issues). 
//                        |
//                        C 10NF
//                        |
//                       GND
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

Heater.

Micro is denoted by the Greek "μ" (Mu).

We cannot do "μ" in good old ASCII text so it is usually written as "u"

For some odd reason whoever did that decided to use an uppercase "U".

So yes, 1uF or 1 microfarad.

Similarly I wonder why they have used "N" which is more normally written as "n" for "nano"

And the "100OHM" thing is a really bad idea. What with the confusion between "0" and "O".

That would normally be written "100R"

mikea

Thanks Heater, assuming the other speaker lead goes to ground I think I have it connected correctly. To power an 8 ohm .25 watt speaker I would need an amplifier right? In the schematic above, will the propeller alone only power something like headphones?

Heater.

You will probably get to hear something.

Better to use an amplifier.

DigitalBob

Try a 33 ohm resistor . So the pin goes to a 10uf (electrolytic cap) (+ )towards pin then to a 33 ohm resistor then to speaker wire the other speaker wire to ground. Then another 10uf cap tied between the first cap and resistor connection and the other cap lead to ground. (For 8 ohm speakers). So your schematic just switch your cap. and resistor positions use two 10uf caps. and one 33 ohm resistor.
For amplifier input use two 1k resistors in series. Pin to the first 1k then the next 1k then to the amplifier. 0.1uf cap. tied to the back to back 1k junction the other cap. lead to ground. a second 0.01 cap. tied to the second 1k output lead then the other cap. lead to ground.
Reference Basic stamp syntax reference manual 2.2 page 446.