Diagram of a circuit generating two adjustable pulses over two hours

[crunch]

Could someone help me with a circuit I’m trying to make. I have a small geared motor that’s 3 volts. No load is about 100 milliamps and with a load I can get it up to around 300 milliamps. I have a micro switch and let’s say that I want an led sitting next to the micro switch. The led is on right now. I push the switch and the output shaft of the motor turns 3 times and stops. 45 minutes later I do the same thing again. The circuit is set to do this only twice in 2 hours. So now the led goes off and the motor will not run either. 2 hours has passed since the beginning and alls well. Now the led is on and the switch can be pressed 2 more times in the next 2 hours. If possible the times should be easily adjustable.
Any help would be appreciated.

Thanks,
Mike

 

[IanP]

Re: Geared motor circuit

Attached you will find conceptual diagram of a circuit generating two adjustable pulses over two hours. It is based on TTL circuits but CMOS equivalents will also performe well ..
Other option is to employ a small microcotroller and concentrate on the software design as the hardware will be pretty straightforward ..
Regards,
IanP

 

[crunch]

Re: Geared motor circuit

Thanks for the info. I have never done anything with TTL but have worked with CMOS a little bit. Do you know what CMOS jparts would be used? I would love to try those microcotroller. I’ve heard of them but that’s about it. (I know enough about some of this to be dangerous) There are so many things I would like to do that I think those things would be perfect for. I would imagine the programmer and the software is fairly expensive and then there’s the old learning curve.
Thanks for your help.

 

[IanP]

Re: Geared motor circuit

Firstly, TTL to CMOS replacements (NOT pin-to-pin):
7400 -> 4011
7474 -> 4013
74123 -> 4528

Nowadays you can get a small-footprint (reduced pins) microcontroller for well below $5, and some of these microcotrollers do not require special programmers; in fact, they can be programmed directly from PCs serial port (with level converters IC such as MAX202, MAX232 or similar) ..
Learning how to program them in assembly or C is not that difficult, so I think sooner or later you will "cross the floor" and try them ..

Regards,
IanP

 

[crunch]

Re: Geared motor circuit

I have worked a little with the 4011 and 4013 but not the 4528. Like I say I have a lot of other projects that I would like to do that I think the micros would be perfect for. If you know of any sites where I could get info on learning this stuff or getting parts, let me know. It would be greatly appreciated.

Mike

 

[IanP]

Re: Geared motor circuit

Here you have assorted links on 8051-family ..
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http://www.intel.com/design/mcs51/manuals/272383.htm
http://www.intel.com/design/mcs51/docs_mcs51.htm
For samples and application notes go to: **broken link removed**

If you want to learn about PICs try:
http://techtrain.microchip.com/masters2004/(pawgfbrrlcuubq4535ztz5fd)/downloads/classes/807/807_P51.pdf
http://techtrain.microchip.com/masters2004/(pawgfbrrlcuubq4535ztz5fd)/downloads/classes/807/807.htm

Regards,
IanP