Hi guys i am very new to all this and want a simple circuit that will replicate the starting lights of a formula 1 race for my sons scalextric. So i have 5 led's and a 1.5V battery. I know how to connect these even with a resistor ! but thats about it. For those of you not aware of the F1 start, I require the lights to come on in sequence at 1 second intervals and stay on until the fifth light is lit when this is lit i then need them to all go out ideally with a random pause between 1 and 3 seconds but if thats too tricky for me then just a standard 1 second interval will be fine. The other thing is that i would like this to be cheap, at the moment my parts cost under 50p I don't want to be buying £20 parts! Also if there is something premade i can just wire into the system that would be great. The other issue i may have is that i don't fully understand circuit diagrams, i'm fine with basic electrics but not electronics !. I you could point me in the right direction for simple explanations that would be great.

 

I don't have a direct IC solution, probably a micro controller is an requirement.

http://picprojects.org.uk/projects/p...Start%20Lights

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Gayan

My Website
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hello
i need Frequency Metter Diagram & All Detail.
thanks

 

helo
Pls Help me i want 12v To 220v 2Kw Invertor Diagram

 

All I have how much do you pay me?

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Gayan

My Website
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helo
Pls Help me i want 12v To 220v 2Kw Invertor Diagram


Here we go again a red box colector

 

hi thats great, but not having a microprocessor programmer ( i know you can buy these pre-programmed for the application i am considering), but is it possible to use a 555 timer connected to each led, or even two 556 and one 555 timer in my case. I think this option may be a cheaper solution for me although not really knowing what i'm talking about maybe a 555 timer doesn't do what i want ?

 

Been a very long time, but could you light them in sequence using R/C timers, a capacitor and a resistor and LED, 5 in parallel. Maybe all the same value capacitors, and progressively larger resistors for the longer delays. It's a toy display, so guessing precisely 1 second intervals isn't needed. Do a search for R/C time constants, should tons of how too's, basic DC theory stuff. Parts could be had for cheap or even salvaged. Now, when you remove power, the leds should go out, but not sure how long it will take each one to discharge the capacitor.

 

I built a drag race start tree that has 3 yellow lights that are 1 second apart then if the "driver" leaves to soon a red light comes on.
very simple circuit built around a 4017 decade timer.
a 4017 decade counter, some flip flop ics to keep the lights lit.
the power supply needs to be bigger as the leds would be dim if lit at all.
estimated cost $10-$15 max
a pc board could be done as well.
lets see if I have this right- 5 leds in 1 second sequence but stay ON.
then all OFF after 1-3 seconds?

 

Reply to MrDEB:

yes that right mate, 5 leds that go on in sequence at 1 second intervals and stay lit then go off together after 1- 3 seconds. Your build sounds pretty similar, I didn't want to complicate mine with a false start mechanism but if thats simple enough then why not - "in for a penny, in for a pound". I will look into 4017 decade counters/timers as i haven't got a clue what these are !

Reply to HarveyH42:

You are correct that the exact timing is not critical as it is just a toy but I do like things to be right. By R/C timers do you mean 555 timers, I will probably answer this myself when i do the search tomorrow.

The other answer is just put my hand in my pocket and buy the pre-programmed micro-controller mentioned in the link submitted Gayan which is excellent it solves the problem. But I can't help thinking that there is a cheaper option, being a Yorkshire lad and all that !

Thanks guys - and extra thanks for being patient I'm learning very quickly

 

this is more than you need as this has 2 24v solnoids that release pinewood derby cars.
two rows of lamps not leds.
If one "driver" pushes his release button BEFORE the green light then that lane gets a red light.
the blue lights are stage or get ready to go.
a third person presses a button and the lights proceed to sequence down -yellow, yellow, yellow, green
after the race a reset button is depressed and you start all over.
hope this helps or gets you started

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	pinetree2.GIF (82.5 KB, 13 views)

 

It does not use a 1.5V battery. A red LED needs at least 2V and the circuit needs more.

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Uncle $crooge

 

Hi proph,

A 555 can help do what you want, but it can't do it alone. And as audioguru noted you won't do it on 1.5V either (at least, not too easily).

I've attached a fairly simple idea I had, which just uses a 555 to generate a 1-second clock pulse which drives a shift register, which in turn drives some LEDs. If you want to use ultrabright LEDs or incandescent lamps then you should drive them via transistors instead of directly from the 74HC164.

Once power is switched on, there is a short delay after which LEDs D2 through D6 light up at one-second increments. After the 5th LED lights up, all stay on until 1 to 3 seconds have passed depending on whether output Q6, Q7, or Q8 is connected to the base of transistor Q1. After that, all the LEDs turn off until the reset switch is pressed.

Transistor Q2, resistor R9, and voltage source V2 are just there to simulate a reset switch and should not be included if this were built. The switch would be a "momentary normally-open" switch wired where Q2's emitter and collector are. Pressing it starts the countup running again (after a short delay).

There are sadly no solenoid drivers nor false-start alarms; it's cheap and cheerful. Just another way to do it.


Cheers,

Torben

Attached Images

race_starter_1.png (20.2 KB, 25 views)

 

I was going to look for a shift register that would keep the leds lit.
the 74164 ?? need to see a data sheet.
would not be too hard to add a false start etc??
Will get back to you tomorrow. Just got back from the BIG city 3.5-4 hours away(read long drive as one needs to drive S L O W as this time of year there is LOTS of Elk and deer grazing adjecent to the highway.The dang wolves are pushing the Elk and deer down from the mountains.

 

I just figured that if you keep feeding 1s to a serial-in, parallel-out shift register, it would count [1,3,7,15,..,n], thereby keeping previous LEDs lit just because the proper bits would be high.

I don't think it should be very hard at all, no.

Neat. Where do you live?


Torben