Maybe use an Arduino? Cost would be about $29 for a name brand one. Takes a little more programming but is reusable and your circuit engineering would be minimal.
-- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ----- Original Message ----- From: "Mark - Myakka Technologies" <m...@mailmt.com> To: "Rory Conaway" <af@afmug.com> Sent: Thursday, January 8, 2015 8:31:44 PM Subject: Re: [AFMUG] OT - EE help please Rory, liking the 555 for now. Any other suggestions welcome -- Best regards, Mark mailto:m...@mailmt.com Myakka Technologies, Inc. www.MyakkaTech.com Proud Sponsor of the Myakka City Relay For Life http://www.RelayForLife.org/MyakkaCityFL Please Donate at http://main.acsevents.org/site/TR/RelayForLife/RFLFY12FL?team_id=1030009&pg=team&fr_id=37555 ------ Thursday, January 8, 2015, 8:34:53 PM, you wrote: RC> Another option is 555 IC's, very easy to work with and a million circuits out there. RC> Rory RC> -----Original Message----- RC> From: Af [mailto:af-boun...@afmug.com] On Behalf Of Bill Prince RC> Sent: Thursday, January 8, 2015 6:25 PM RC> To: af@afmug.com RC> Subject: Re: [AFMUG] OT - EE help please RC> Make something simple with 3 binary timers RC> (http://www.radioshack.com/nte74ls163a-ic-ttl-binary-counter/55051075.html#q=counter&start=1). RC> So you would need an oscillator. You can make one with a RC> couple of cross-coupled transistors or just use a couple of RC> cross-connected flip-flips. RC> Feed the timer into each of the counters that is enabled by RC> each switch plus the output of the previous counter. If the RC> counter overflows before the next switch is pressed, then nothing RC> happens. RC> That make sense? RC> bp RC> <part15sbs{at}gmail{dot}com> RC> On 1/8/2015 5:09 PM, Mark - Myakka Technologies wrote: >> I'm working with some kids on a school project. They want help with a >> simple circuit design. Bare with me as I explain this. My circuit >> design skills are VERY basic. >> >> We will have 3 momentary switches (1 2 3). If they are pressed and >> released in the order of 3 2 1, we need it to trip a relay and keep it >> tripped for about 4-5 seconds. Any other order and the relay stays >> closed. Also, there should be a reset timer such as if 3 and 2 are >> tripped, but nothing happens in x seconds system resets. >> >> This will be running off of 4 AAA or 4 AA batteries. This device will >> be used for 5-10 minutes at a time. >> >> I'm trying to keep it basic as possible. These are 6 & 7 graders with >> zero electrical knowledge. If the circuit get too complicated, their >> eyes will just glaze over. >> >> I was thinking about something with capacitors. I know they store and >> release energy and have some timing specs. >> >> >> --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com
