Help with circuit diagram please

Do you mean 20 4.8v 3A lamps? Or 20 4.8v 3W lamps?

My first thought as a nice very simple solution for a non-electrician would depend on whether you could change the voltage to 12v or 6v. In which case you could simply go to a vehicle scrapyard, get some auto direction indication flasher units and use those. A motorbike one may be a suitable 6v unit instead of a car's 12 volt unit.

My next thought is to get some Christmas tree flasher lamps (they are special lamps that come in sets of christmas tree lights, to make the lights flash - or you can buy them as individual lamps). Pick the right one and put it in series with the right relay and it will flash your lamps string for you.

My next thought would be to use cheap and cheerful 555 timer kits. In the Uk one can buy "universal" 555 printed circuit boards that can be set to work as a ~ 1 second flasher by putting the right links on the board and choosing the right components. I assume that you cna get them in the US, if that is where you are? They won't be able to drive the lamps themselves, but will be able to operate small relays or power transistors. You can do all sorts of effects with a 555.

Any of those ideas any use? If any appeal, I can elaborate.

i assume you mean lights here. could you clarify?

They

i assume you want to have a flashing guitar that you or somone will actully play. can you hard wire a controller to AC power? if you can use a standard chase light contriller (modified as needed) as used for DJ lighting effects / rope lights. if the guitar has a pickup you may get popping noises as the chase operates.

anything other then LEDs will consume so much current that battery life will be short for any size battery that you would care to carry around.

Basically I

Hi

Sorry my mistake. The lights are 4.8v 3A, there will be aproximately 20 of them on the guitar. The Batteries are 4.5V. Wiring to AC power is not really an option but the guitar would only need to operate for 5-10 minutes at a time to battery life is not a major concern.

The 555 idea sounds promising, I am resident in the UK can you give me some more information on this please?

Thanks!

Trevor

You can buy printed circuit boards from rs components rswww.com under part number 434-071 - you local electronics shop (not maplins) will possible stock or be able to order them for you. This pcb will easily allow you to build a 555 timer chip based flasher, with whatever repetition rate you want. I can give you the component values for a particular rate, although the associated rs data sheet does make these easy to work out.

Using you lamps as 5 groups of 4 (series parallel of 2 x 2 and using your two batteries in series) and with only one group on at any time, that is 6 amperes average load and to last for 10 minutes, your batteries would have to be about

2.5AH each.

The 555 won't switch 6 amps - so you will also need relays (eg Maplin RP68Y) to switch the lamp loads. You will also need to strap a diode (eg a 1N4004) across the relay coil to protect the 555.

How does that sound?

Hi Sue

That sounds great! Only problem is my extraordinarily low level of knowlege. Is there any chance you can supply me with a list of the components and a diagram of how to assemble them, then i think i can manage the assembly. If that is going to take too much of your time then no problem. I had a look on

but couldn't find the bits you mentioned although i was probably looking in the wrong place.

Many thanks for all your help!

Trevor

The address is rswww.com - a bit unusual.

Basically, the board has links that allow you to use the 555 in a number of different ways. You want it to run as a simple free-running oscillator, so, on the board, you solder in link "ast".

Now the component values.

Look at the diagram here for duty cycle

Hi Sue

I'm not local to Dartmoor but if I were to send you the relevent components and the money for a few pints of cider how would that sound? ;o)

All the best

Trevor

Yep, I would be happy to do that for you. We do need to firm up on exactly what the controller should do.

Let's say we go for five circuits, each with a group of 4 lamps wired in series/parallel.

Do you want the first group to light for a second and go off, followed by the second, third, fouth, fifth - and then repeat? Do you want a gap at the end, before the first group lights again? Is the one second right, or do you want it adjustable? If so, over what range?

Have I got the wrong idea and do you, for instance, want all groups switching at random, each on for 1 second? Or make it sound activated? Or light activated?

We will need to ensure that the batteries you propose to use are up to the job of powering this for the length of time you want - so send me the details. As another poster remarked - this is one heck of a load for small batteries.

Pleae feel free to email me (leaving off the invalid bit) and we can discuss exactly what it should do and other matters, without boring everyone else.

I don't propose to charge you a penny - not even the cider (but please pay the return postage) - but will use one of the local charities that I do voluntary work for as a contract address and you might like to donate a few bob to them when you are happy. I hope you understand why I wouldn't want to give my home details out to a stranger on the internet.

please list the lamp number. most 4.8V lamps that i see are much lower current then 3 amps

The Batteries are 4.5V.

please list the battery nunber you are planning on using. my feeling is that at the currents you are talking about these alkalines are likely to get very hot if not actually explode.

Wiring to AC power is

is the guitar accustic? electric? or electric/accustic? were you planing on having the battery internal to the guitar? or worn on a belt pack?

IIUC, the OP wanted to run these as 5 groups of 4, only one group on at any time. Arranged as a series/parallel set across 9V, this will give a battery current of around 6 - 8 amps (allowing extra for keeping the filaments warm whilst nominally off).

Now for NiCads (I was going to suggest 4AH D cell NiCads rather than alkalines) the maximum continuous discharge current is around 10C or 35A whichever is lower - without cooling. So that should easily give him the 10 minutes run-time wanted.

Would 6 D cells be a problem for any of these? ISTM that fitting 20 lamps and the associated wiring would be more problematic. But, IANA guitarist..

filling up the interior of an acoustic will change the tone. there is no interior in an electric to fill up.

my guitarist friends would be aghast at the idea of modifying an instrument in this manner.

if its strictly for a visual effect i guess it would not matter.

id recommend flashing LEDs each powered by its own little battery and stuck on with Velcro. that would give the whole thing a twinkling effect, be lightweight, long lasting, safe, and non invasive to the guitar.

e

,snip>

Anything that anyone did to a guitar before I played it=20 would be bound to be making an improvement - provided it=20 made it quieter..

What you suggest makes a lot of sense to me. Button cells=20 would be fine for the operational time required.

--=20

Sue

,snip>

Anything that anyone did to a guitar before I played it would be bound to be making an improvement - provided it made it quieter..

What you suggest makes a lot of sense to me. Button cells would be fine for the operational time required.

Hi Sue

I tried e-mailing you leaving off the invalid bit but it got bounced. Can you e-mail me at snipped-for-privacy@btopenworld.com and I will reply?

Thanks

Trevor ;o)

Yep, but the email addy should have worked ok.

No Problem!