T&L Publications

((even the spammers were encrypted while created user accounts , (different protection called for)))

reported to admin this mornig

reported to admin this morning

What is your major?

Oh yeah! How waterproof? Rain/spit/sweat? Or, submerged? (and depth?)

Not a truely rigid bubble. Sound (higher and lower preasure) on the outside needs to deform/flex to make higher and lower presure in the air inside.

Same for "Gummy Bear" soft, except sound is absorbed, nothing inside to vibrate the mic element.

The pick of a part usually narrows down to one or two when you "do the numbers". Following your power supply cap example - You need the minimum voltage the load can run with, and maximum current it will draw. The peak of the maximum rectified voltage minus then minimum the load can use is the supply...

Wiper of a pot to IC temperature measuring pin. Ends of pot to Vcc and common. Adjust pot till IC cuts the charging current. Measure voltage at wiper. Warm NTC to temperature where cell charging should stop. Measure resistance of NTC. A touch of algebra (or longer way with Ohm's Law) gives resistanc...

Are you talking about servos that set the position of the output shaft based on pulse width of the input pulses? What does the wireless analog to digital converter (ADC) have to do with pulse width control? ADCs convert a level to a digital number. The pulses to a servo are at ON level or OFF level;...

Two components and three connections complicated????? The NTC is in physical contact with cells. It's resistance changes with temperature OF THE CELLS. The junction of NTC and a fixed resistor is wired to (pin 1?) of the IC. The IC circuitry measures the voltage to control the charge current. The ot...

sure! the bulbs will be too much current for 2N3906s, so use LEDs and 1K resistors.

Last night 20 logins, nothing; today 2 like you said.

try to attach schematic, get logged out

Without R3 the circuit is not a schmitt trigger anymore. The Q1 base resistance to negative supply is like 1 or 2 Ohms (bad!). With R3 the base resistance is like 50K to 100K (no burnt pots). R3 being "shared" with Q2 causes the "snappy" switch between which transistor is on. It is better to put ori...

Looking at it again -

What else have you done?

R3 times the gain of Q1 should have prevented pot burn-out.

What colors are the bands on R3?