On June 3, 2009 at 12:23, Gizmologist09 said...
A touchtone phone pad generates a 2 tome pulse that is identified by a discriminator and says the if these 2 tones are read simultaneously, "I will turn this particular circuit."
On June 3, 2009 at 12:46, Ernie Bornn-Gilman said...
That's true, except that a touchtone phone pad generates a 2 tonse series of pulses, not a pulse. [I meant "2 tone," not "2 tones," and definitely not "2 tonse"]
On June 3, 2009 at 15:12, Gizmologist09 said...
Sorry to disagree, but A DTMF tone is only 2 tones transmitted simultaneously. The discrimination circuitry identifies those 2 tones on a matrix, just like a keyboard. The pulse duration is the amount of time you leave your finger on the button.
Who are you arguing with here? You say a touchtone pad generates a 2 tome [tone] pulse, I say it's a series of pulses, then you disagree with yourself, saying it's "only 2 tones"!
Why use a relay with high current draw and noisy contacts when a surface mount transistor can perform longer, faster cheaper and much smaller smaller?
I already answered this. Is is decidedly NOT cheaper for me to fabricate ONE solid state control device than to solder some wires to a relay, even if it's mounted on a board and mounted inside a box. It never occurred to me that you meant an SMT device. I'd have to buy the hardware to build ONE, and that would cost even more. Agreed, an SMT 555 circuit would cost less than a relay circuit, especially if you're doing a thousand of them. But the question answered was about doing ONE or a small quantity.
