Synopsis:initial status is everything offinstant 1, the button is pushedinstant 2 trough 3, led blue is oninstant 4, led blue goes off while green leds go oninstant 5, the button is pushedinstant 6, green leds go off and blue goes oninstant 7, blue led goes offEach "instant" can last several seconds at your choice.Now, the monostable keeps the output high for X seconds.Your green leds should stay lit UNTIL you press the button again.This means you can't use a monostable.You have to delay them lighting up, and during the delay you have your blue led on, but once the delay is finished and the greens go on, you have them on for an indefinite period of time.This means no monostable.Unless i got it all wrong :)

Why not use a GAL? GALs can be programmed, erased, and reprogrammed to provide infinite logic models.Your circuit above is good, and most likely will work, but it's 'set in stone'. Any changes you need to make would require a new circuit design, a new PCB most likely. a GAL provides substantial flexibility without the requirement for hardware changes.I'm sure your school has access to a GAL Programmer and possibly some pre-written programs that you could look at. While a GAL might be overkill in this case and probably circumvents the original intent of the class to provide a solid grounding of discrete electronics, it might be something no one has thought of yet and therefore would be 'Creative'.

----------(quote)Each "instant" can last several seconds at your choice.Now, the monostable keeps the output high for X seconds.Your green leds should stay lit UNTIL you press the button again.This means you can't use a monostable.----------The monostable keeps the output high for 6, 7 or 8 seconds. This high signal will turn on the blue led indeed. Since the monostables output is inverted (after the OR) by the NOT, it will keep the green led OFF (provided the "switch" is set to ON)When the "switch" (flipflop or whatever) is closed the input to the OR will be 1 and thus the output will be 1 for sure. Inverted bu the NOT that is 0 >> the green leds are OFF ! No matter what the monostable outputs.Now when the "switch" is opened, the output of the OR will depend on what the monostable gives as output. If it gives a 1 (for 6 seconds), the OR will output a 1 for 6 more seconds (inverted = 0 => leds stay OFF)Once the input from the monostable becomes 0 (after 6 seconds), the OR output will change to 0 (both inputs are 0) .. inverted via the NOT that is 1 so the green leds go ON.It is the monostable that gives the delay for the leds to go on, while it is the "switch" that ensures they go OFF.----------quoteYou have to delay them lighting up, and during the delay you have your blue led on, but once the delay is finished and the greens go on, you have them on for an indefinite period of time.This means no monostable.Unless i got it all wrong -----------You got it all right except for that last sentence "no monostable". It is the "switch" that keeps the green leds OFF, while it is the monostable that powers the blue one ON and powers the green ones ON( HOWEVER inverted) => keeps them OFF.I think it should be clear now.I am quite sure that my system works right :)

if switch = on__if monostable = on____blue led = on____green leds = off__else____blue led = off____green leds = onelse__if monostable = on____blue led = on____green leds = off__else____blue led = off____green leds = off

What is a GAL?By the way Philippe, this is for future:microchip's PICs can be programmed in visualBasic :)Well at least there is a basic for pics, in the form of a compiler called PicBasic.You may want to investigate this for your future cockpit works ;)

Got it :)I am studing Automation (Bode Nyquist Nichols and their parents) i have my head full of block diagrams...Sorry for misleading and bothering you :)I beg your pardon

Ok this brings up a few questions & remarks:1) what does a GAL cost ?2) tnx for confirming my cirquit is good :)3) i am not going to make a PCB, just a perfboard with wires4) I believe I can change times from teh 555's by chosing for trimmers and not resistors.Also "set in stone" is nor problem .. it is meant for my sim and it does exactly that which the F50 does so .. why would I want to change it :)Ok, now I need confirmation on a few things:1) the relais shown in the cirquit is wrong ?2) which components behaves as a switch then ? (i give a single input from the pushbutton and I need a "switch" to flip on, off the next time)3) how to calculate the resistor and condensator (what's the correct english word for these agian ...) values ?

Lol no problemo ;)It only helps. I wasn't sure before, now I am :D

>1) the relais shown in the cirquit is wrong ?A relais depends on the current on the coil: it will not hold the position when you release the button.Unless you are using a double coil relais, but in that case you'd need two buttons: one for each coil.>2) which components behaves as a switch then ? (i give a>single input from the pushbutton and I need a "switch" to flip>on, off the next time)flipflop, it's something like AND,NOT,OR ports: you find TTL chips with flipflops in them.One pulse on the trigger and they change state.CDxxxx or something like that.>3) how to calculate the resistor and condensator (what's the>correct english word for these agian ...) values ?That's my tricky part: i am experimenting for another thing that hasn't quite anything to do with planes (who said strobe light??? :-lol) and i found that the formula on my DS wasn't right.Or at least i wasn't able to make it work.Right now i am using it has an astable and getting fair enough results with 100ohm + 10k pot and a 220uf (polarized, as to say electrolitic) capacitor.With the pot i go from something like 80hz to 15s per cycle.And exact english words areresistor and capacitor :)

New cirquit design:http://users.skynet.be/plipke/Schema3.GIFThis time the relais has been replaced by a JK FlipFlop chip. Both J and K will be kept high so that it behaves like a T FlipFlop (toggle).Then the cirquitry for the 555 timers has been modified according to most cirquits found on the net.

Wow! Has your class addresed the issue of circuit reduction or simplification? The 555 circuits as they are now are somewhat overly-complex. The R/C filters could probably be reduced to a more basic configuration.You also have the 3 555 timers labeled as "IC1" (Points off! =), and the Quad NAND / Hex OR circuits might use a little cleanup.You may also smoke-check IC4.. as I think the 7473 is a TTL 5Vcc supply. I may be wrong though.Also, you are mixing CMOS and TTL. I'm not sure if that's good design practice... However, I may also be wrong on that as well... (My usual disclaimer :-) )

> Wow!lol> Has your class addresed the issue of circuit reduction or> simplification?not at all .. we didn't learn about IC's or timers or whatever.. we just learned how to wire a LED to a 4.5V ...> The 555 circuits as they are now are somewhat overly-complex.i changed them to what I find mostly on the web as cirquitry for the 555. compare these:http://technologystudent.com/elec1/5553.htmhttp://technologystudent.com/elec1/5554.htm> You also have the 3 555 timers labeled as "IC1" (Points off! =),> and the Quad NAND / Hex OR circuits might use a little cleanup.My first idea was not to use a NAND. I wanted to simply use "normally closed" transistors, but I don't know if those exist and the guy at the shop looked kinda weird at me and then started talking 'bout the NAND .. now I asked him for transistors today to purchase and he asked me "normally closed or opened" ?? (my reaction: ##### ! :( obviously)Sure this cirquit could be done a lot more efficient .. but I don't care much for that at the moment. All I need to know is: will it work like I expect it to. The thing is .. I 'm not studying electronix whatsoever. Just some basics so that we can solder, use leds, calculate how long a batery will last with it etc etc. I just wanted to do something more usefull than just make a led light up and combo it to my sim. That's why it got so complex.> You may also smoke-check IC4.. as I think the 7473 is a TTL 5Vcc> supply. I may be wrong though.Oops .. I'll check ! If I got this wrong I will need an other one. I am soldering the cirquit using sockets for the IC's so I can change it, right ?> Also, you are mixing CMOS and TTL.??

auwch .. truethe flipflop is 5V :snow what ?

where can i find a similar flipflop that takes 12V ?or should I use a component that reduses 12V to 5V in front of this flipflop ? if so .. what happens to the output ? will that be 5V as well ? and would that be a problem ?

555 can work from 3v to 15v.Just power everything with 5v and you're go for launch.