breadboarding for beginners

[Rob]

http://led.linear1.org/breadboarding-for-beginners/

I expect a lot of followup questions on this one. Ask, and I'll do my best to help.

[mike-heli]

hello Rob

Well i got the 555 circuit working on a breadboard.
now a couple of questions:

how can i make it do 3 flashes - then 1.2sec gap - then 3 flashes - repeat over.
how many Ah or mAh is a 9 volt batt capable of supplying - it is a 160mAh rechargable NiMH
how do i add a varible resistor in place of R2 on this diagram
how do i convert the diagram to a simple 'proper' mini circuit board - or more accurately what would be the typical circuit baord layout for this diagram

Thanks

[cpemma]

Well i got the 555 circuit working on a breadboard.
now a couple of questions:

how can i make it do 3 flashes - then 1.2sec gap - then 3 flashes - repeat over.

A second 555 running a lot slower, so it enables the 555 for 3 flashes then disables it for the 1.2 secs... or a 4017 counter running off the 555 circuit that lights on outputs 1, 3, 5, then off for 6-10 might give a suitable effect. 

Search out the datasheets for the 2 chips, plenty of examples IIRC.

On breadboards, I always have problems on my board trying to fit the wideish pins on TO-220 power transistors, any tips? Are some boards easier than others?

[mike-heli]

thanks for that
I have another 555 handy also i have 2 556 so i shall have a play now
are you in the UK - Rob mentioned you

[Rob]

or a 4017 counter running off the 555 circuit that lights on outputs 1, 3, 5, then off for 6-10 might give a suitable effect.

I like this idea quite a bit--mainly because it's more educational than the previous alternative.

There's a whole class of digital circuits called synchronous digital circuits (which use a clock, as opposed to asynchronous which don't). The 4017 idea is a nice gentle introduction into that world.

If you get started building synchronous circuits, you'll often reach for a 555 as a simple way to provide the clock that advances the circuit through states (although to be fair, there are counters with the clocks in them already, and one of those would be ideal for a project like this).

[cpemma]

Just to show what's involved with the 4017 method,



Power supply connections to the 4017 aren't shown (a common feature of logic circuit schematics) but the datasheet shows which pins go where. The 3 diodes steer the output signal from a 'high' pin (eg, #0) without letting it short to a different pin (eg, #2 or #4) which will be 'low' at that moment.

On your variable resistance (potentiometer) question, take your connections from the middle leg (the moving contact) and one of the outer legs - pick the wrong outer and you'll turn clockwise for less instead of more, that's all.

[mike-heli]

Excellent

Thank you

I am learning about this fast so I think I should be able to do this.
I have 2 programs, 1 called 'livewire' and one called PCB Wizard 3 - They are helping me tremendously also.

I will get said i.c tommorrow and let you know the outcome.
I got a perfect working strobe effect from the basic 555 circuit but don't know how to manipulate it further. - So I'll try your method.

I have just been playing with a Luxeon IV - amazing!!!

Thanks again

[cpemma]

I have just been playing with a Luxeon IV - amazing!!!

Just don't connect it direct to a 4017 (or a 555 come to that), the 4017 will only deliver a few mA... but you can use the output to switch an NPN current-booster transistor no problem.

[mike-heli]

Thanks for all the help on this eveyone.

I did get many variations of the suggested circuits working - but ultimately could not get the results I required with my limited knowledge.

I am going to go for PIC Chips for the heli lighting project .
Why I didn't think of it sooner I don't know.
It is so easy to do stuff like this with a pic chip

Will show you the final results soon.

Thanks again