Need device suggestions

Egg timer?

Check out watches and stop watches designed for sailing. They have count down timers with speech output... "2 mins....1min....30 seconds.. 20 seconds

seconds

Also Google for "count down timer" programs for the PC..

I found a doohickey (that's the technical term) that flashes when time is up and recalls the previous setting so I -could- wire two of them together with one set at 5 mins and the other at 4:30 mins. But now I am at 2x$35 ($70) for each of two devices. And the adv. for them isn't clear whether it actually handles seconds (useful) or just whole minutes (useless).

I could handle the mechanics of breadboarding this device, but I haven't even clue-one for how to make a circuit that starts and stops via remote control or count part-way down, start flashing, and continue counting for another 30 seconds. That's the part I was hoping this group could steer me towards.

Can someone point me in the direction of radio-controlled on-off switches and countdown timer circuits? MAYBE I could tie an on-off switch into an existing timer.

Egg timers, etc. don't achieve the goal because we want the device to be unobtrusive to the speaker (so as not to divert their attention unduly), brain-dead simple (one button or less to operate) and invisible to the audience. In other words, the device should not announce "Hey, split-pea-for-brains, your talk is running overtime!" so that the audience is made aware of this.

I'm still searching and the floor is still open for suggestions.

Bill

The ones I've seen speak the mins, then when the time gets down to the last min (or 30 seconds?) it startrs speaking every 10s, then in the last

the easiest way is probabkly two build two countdowns. it depend how much accuracy you need.

buy a cheap radio controlled toy: keep the radio part and replace the mechanical toy part with a light-blinking machine.

Bye. Jasen

Sounds to me more a job for a cheap 8-bit (or even 4-bit) microcontroller. All the I/O stuff on-chip, even a built-in oscillator, just write a simple program for it.

Any reason not to use infrared? Universal remotes are cheap and ubiquitous, and it should be fairly easy to connect an IR detector to your microcontroller and program it to recognize whatever you want for an "on" or "off" signal. I used to do things like that once upon a time...

Of course, this is only if you feel confident doing this yourself. Paying someone to do it will cost you well over the $70 you'd pay for the doohickeys. Then again, if this is to be a mass-produced product, paying someone $1000 or more to make the design doesn't seem to be a problem if the cost per circuit is around a dollar and you'll be selling thousands.

A cast-off TV remote and an infrared detector / integrator triggering a flip-flop.

That's 300 seconds.

That's 270 seconds--9 parts out of 10.

That's 10 parts out of 10--the last output of a CD4017. The previous state was the 9th output of the decade counter.

To get the 30-second clock, use a chip with a binary divider chain and an integral oscillator (CD4060). Tweak this.

AND the output of the 4017 with one of the lower-count pins of the

Essentially 4 chips and 2 LEDs. The battery is the biggest single part. The chip count goes down to 1 if you use a microcontroller.

One more section of the AND gate chip.

Before you start any of this, you need to find a flesh & blood person who has previously held the proper end of a solder iron.

The soldering is the part I -can- handle ;-)

The rest of your response sounds incredibly intelligent ... but well beyond my experience / training.

Sheesh ... I wish I was as smart as people tell me I am.

When I was a kid (several decades ago), I would have just trundled off to the nearest electronics component store with the shopping list and started piecing things together. Now, decades later, I am probably reduced to cannibalizing toys and egg timers.

Sigh.

Bill

Like they say, One man's trash, is another man's treasure! Not only do you have the fun of building what you want, you learn to do rework by carefully salvaging the components, and end up with a project that cost little, or nothing to build. :-)

As far as your project goes, I would either use a pair of countdown timers, with the first starting the second, or use one of the PIC or similar low end microprocessors that have free software to program, and a cable that can be made for a couple dollars. As a last resort, a computer program and an old laptop that counts down in front of them, and changes the background color at 30 seconds remaining.

Bill>The soldering is the part I -can- handle ;-)

Actually, *solder[ing] iron* was a metaphor.

Exactly my point: **Ideas** are a dime a dozen.

You need someone who

There are still some left where I am

--but today you don't even need to leave your keyboard.

A *microcontroller* is the way these things are done nowadays. Almost everything is done in software (and when it needs to be altered, often you just tweak the code). See if you can't find a local guy who does that. Got a community college or high school nearby? Maybe barter with him for something within your skill set. Maybe he'll teach you a few of the tricks to boot. . . WRT your posting style: NOT *3* hyphens.