Miniature Electronic DC Sequential Timer

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jfulla
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Miniature Electronic DC Sequential Timer

Post by jfulla » Tue Jan 03, 2006 2:29 pm

Hello- I am new to this site and I have several questions for the experts.

Miniature Electronic DC Sequential Timer, that's the only name I can describe it with. I need your expertise in finding out how to build a relatively low cost electronic contraption for my plastic aircraft static display models. I want a switching box that can be programmed to turn things on & off at different intervals and at varying time lengths. The power source is DC, run off of batteries. The box would ultimately be very small, and counter-sunk in the bottom of the wood base that the aircraft model was mounted on, or even built inside the model itself. A miniature high-definition speaker for sound would be built into the base, as well.

Example: A button is pushed, and these things happen in order:

1. Wingtip navigation lights come on. 2. Pre-recorded sound (engine crank-up) starts. 3. Propeller starts turning. 4. Propeller keeps running. 5. Wingtip landing light comes on for a predetermined time length, then goes off. 6. Propeller slows down & stops. 7. Sound stops. 8. Wing tip navigation lights go out.

I know this is possible with the right IC chips and schematics, but I don't have any idea how to find the plans. I have asked people in Model Railroad shops, even aircraft avionics people, & no one has a clue. Once upon a time, the parts for something like this could have been bought from Radio Shack and put together.

Another similar question I have is how to record a sound digitally and put it on a IC chip, so it is played in a circuit ( like the voice stamp on a telephone answerer). This sound could now be played through the system in the model that I described above.

jimandy
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Re: Miniature Electronic DC Sequential Timer

Post by jimandy » Tue Jan 03, 2006 4:57 pm

By golly, you have come to the right place. It might be helpful if you could describe your skill level in electronics, i.e., ever built any kits? know how to use a soldering iron? familiar with basic components - resistors, capacitors, ? Do you know what a printed circuit board is? You're gonna get a lot of ideas here on how to do what you want to do and you've done a great job in your topic intro posting.
"if it's not another it's one thing."

jfulla
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Re: Miniature Electronic DC Sequential Timer

Post by jfulla » Tue Jan 03, 2006 5:25 pm

Well, I have put miniature lights, motors, and circuits in many plastic model projects. My favorite lights are LEDs, along with miniature incandescent lamps. I usually have soldered these into several separate circuits with a momentary SPDT switch, 30-gauge wire, heat shrink wrap and AAA batteries. My favorite soldering iron is a Weller 921Z that has great miniature soldering capability. Most of my supplies have been bought at Radio Shack, Miniatronics, Digi-Key, Light Systems and other hobbyist sites. However, I know NOTHING about creating a program where these items could be set into a timed event, say about ten seconds apart, at the press of a button. HELP!

rshayes
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Re: Miniature Electronic DC Sequential Timer

Post by rshayes » Tue Jan 03, 2006 5:36 pm

This can be done with hard wired logic on perf board using CD4000 series logic. A shift counter is especially easy to decode for varying time intervals. No programming software or programming interface will be needed. The disadvantages are the amount of hand labor, the number of chips, and the physical size. A printed circuit board could also be used.

The next step up would be programmable logic, such as the Xilinx CPLD parts. The programming software is a free download, but you will have to build a two chip programming interface, and the chips are surface mount parts. This will require a printed circuit board.

The PIC series, and similar microcontrollers, are very popular solutions also. These also need programming software and a programming interface. Some of the chips may be available in DIP packages, which can be wired on perf board. Otherwise, this will also need a printed circuit board.

The programmable parts require programming software. This may or may not be available as a free download. It will also take quite a few hours to learn how to use the software. Programmable devices also may require you to build or buy a programming interface.

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jwax
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Re: Miniature Electronic DC Sequential Timer

Post by jwax » Tue Jan 03, 2006 6:56 pm

A LM558 Quad timer would provide the timing of the four events nicely. An ISD voice chip would provide the user-installed propeller sound, and a pot on each timer would control the duration of each event.
Here's a tutorial on the timer- the LM558 has 4 of them in one chip-
http://www.uoguelph.ca/~antoon/gadgets/555/555.html
Looks like a nice project! :)

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philba
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Re: Miniature Electronic DC Sequential Timer

Post by philba » Tue Jan 03, 2006 9:29 pm

It could be done with timers and such. I think you would have to use the cmos 555 to get longer times. Also you will need timers for the start time and the stop time. I'd used potentiometers so you can control timer duration.

However, a microcontroller would be much more flexible and take less circuitry. given that you don't have any experience with programming, I think this is going to be hard to do with a microcontroller. If you are willing to try, I'd recommend the basic stamp. I think the BS 1 project board would be sufficient for this - they run about $30, iirc. There is tons of info online for this and a simple sequencer is pretty easy to write. it would just be a sequential list of on or off commands and timer delays. very simple. check out parallax Look at the prop-1 controller. you get 8 lines with some driver capability - $35. it seems to have been designed for your application. You will also need the serial adaptor for the prop-1 controller.

What ever you do, you are going to need to understand how to drive motors and lights with out blowing up your electronics. There is lots of info at discover circuits

<small>[ January 04, 2006, 12:09 AM: Message edited by: philba ]</small>

jimandy
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Re: Miniature Electronic DC Sequential Timer

Post by jimandy » Wed Jan 04, 2006 1:10 pm

Could take a low pulse rate clock chip and have it drive a 1 of 8 or 16 data distributor (4028, 74C154)), and, as the clock cycles, each output line in succession goes on/off. By connecting those outputs, in accordance with your desired sequence, to the set and reset lines of a quad flip-flop (4043?) you could control sequential events and (I think) have them overlap each other. Or consider using a small burnable PROM. Could be addressed by data lines of a counter (4024?) driven by a low pulse rate clock chip. Four of the PROM data lines then trigger your lights, etc. My projects are all digital as much as possible as I hate to figure out resistor and capacitor values for timers and it's easy to debug digital by single stepping the clock.

Either way, as philba suggested, the other design challenge is to interface those logic level lines with the light bulbs, sound chip, propeller motor, etc. MOSFETS are probably the ticket.

I throw these ideas out there without really putting a pencil to it but rather for others to comment on or to flesh out if practical. But it sure would be fun to prototype! Unfortunately, my basement shop is a disaster and my new year's resolutions did not include cleaning it up.

Oh, yes, I think Radio Shack still sells the little proto boards, a necessity for this kind of design testing, but for chips, you'll be out of luck there. Too bad, it used to be a challenge to design gadgets from parts all available at R.S.
"if it's not another it's one thing."

vidi0816
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Re: Miniature Electronic DC Sequential Timer

Post by vidi0816 » Mon Sep 08, 2008 8:45 pm

That's very easy...you just controlled with controller and ISD IC, you just colect how much time in every speak each step, and then you can buy ISD17xx IC. xx is how long you will take a maximum speak is.

Regards,

Adi

jfulla wrote:Hello- I am new to this site and I have several questions for the experts.

Miniature Electronic DC Sequential Timer, that's the only name I can describe it with. I need your expertise in finding out how to build a relatively low cost electronic contraption for my plastic aircraft static display models. I want a switching box that can be programmed to turn things on & off at different intervals and at varying time lengths. The power source is DC, run off of batteries. The box would ultimately be very small, and counter-sunk in the bottom of the wood base that the aircraft model was mounted on, or even built inside the model itself. A miniature high-definition speaker for sound would be built into the base, as well.

Example: A button is pushed, and these things happen in order:

1. Wingtip navigation lights come on. 2. Pre-recorded sound (engine crank-up) starts. 3. Propeller starts turning. 4. Propeller keeps running. 5. Wingtip landing light comes on for a predetermined time length, then goes off. 6. Propeller slows down & stops. 7. Sound stops. 8. Wing tip navigation lights go out.

I know this is possible with the right IC chips and schematics, but I don't have any idea how to find the plans. I have asked people in Model Railroad shops, even aircraft avionics people, & no one has a clue. Once upon a time, the parts for something like this could have been bought from Radio Shack and put together.

Another similar question I have is how to record a sound digitally and put it on a IC chip, so it is played in a circuit ( like the voice stamp on a telephone answerer). This sound could now be played through the system in the model that I described above.

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CeaSaR
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Post by CeaSaR » Tue Sep 09, 2008 3:58 pm

Analyzing the needs, you want 4 distinct timing events of differing
lengths, not sequential events.

1. Initial startup turns on navlights, stay on till done.
2. Sound starts, runs for predetermined time.
3. Propeller starts and runs for predetermined time.
4. Landing lights come on for short predetermined time.

Theoretically, this could be accomplished with a 556 configured as 2 single
shot timers. The first would start the first 3 events at the same time,
achieving distinct start times using delay tactics (R/C probably) to set the
different starts. The second timer would have an initial delay to run the
landing lights. Once all power is used in the caps from the button press,
everything turns off. "Theoretically".

I think your best bet is to have a small "PIC" or equivalent with at least 5
I/O lines (4 items above and the switch). This would provide the best
control over your events, and the "PIC" could be put into sleep mode
between button presses to draw VEEERRRYYY little current while
maintaining "active" status, staying ready to go. The plus to using a "PIC"
is that you can program in soft start and soft stop to the propeller(s) to
create a very realistic simulation

Just my 2 cents worth.

CeaSaR
Hey, what do I know?

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jwax
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Post by jwax » Wed Sep 10, 2008 2:21 am

I wonder if jfulla is still working on this, almost 3 years later. :???:

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MrAl
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Post by MrAl » Wed Sep 10, 2008 8:57 am

Hi again,


John, yeah good point...jfulla's last post was back in Jan of 2006 ! Wow.
That was a long time ago. Im betting that vidi didnt realize it was so
long ago. Also, jfulla only posted twice on this board. He probably did
something already to get things going.

Too bad too, there were a lot of good ideas in this thread.
I was going to suggest another...a 16 bit counter and 16 to 1
decoder...to get 16 different time events. Wont do much good
though if the OP doesnt return.
LEDs vs Bulbs, LEDs are winning.

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CeaSaR
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Post by CeaSaR » Wed Sep 10, 2008 3:22 pm

Unfortunately I missed the date on the OP's post. I'd like to know what he
came up with to solve his dilemma.

CeaSaR
Hey, what do I know?

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MrAl
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Post by MrAl » Wed Sep 10, 2008 5:47 pm

Hi again,

Yeah me too. See if he used one of the ideas or something else.
LEDs vs Bulbs, LEDs are winning.

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