Electronics 2000

Hi everyone, Im completely new to this forum.

I manufacture custom one-off Electric Guitars. Sometimes, I get asked to do some wacky stuff, and generally I manage to achieve everything the customer would like. However, as builds are becoming more and more sophisticated I need to look further afield for help and advice, especially on subjects that are totally Alien to me, such as Electronics. I can custom wire a guitar, no problems at all, its custom circuitry that I struggle with. Hence the reason why I am here.

Im on the look out for some one, or a group of folk who can help me design and build small custom circuits to install inside some of my guitars. I don't expect anything for free, I do like to pay my way, so please don't think Im on the scrounge.

My first problem, is that I am currently building a guitar in the theme of a 1971 NASCAR Dodge Charger V8 Race Car ! Sounds simple enough, but this baby has 8 exhausts ! Also, I need to install a standard retro look electronic Rev Counter into the body. The problem is, I need the rev counter to cycle up and down the gauge as though it is being revved up, if you know what I mean. Ideally it would be great if the rev counter would respond to an external sound, either through a miniature microphone that I can fit somewhere or a signal from the pickups. Failing that, just a simple up and down the scale movement every few seconds would be good. I haven't a clue what to do with this, and need an expert.

This is just one example of something that I need right now. There will be plenty more devices needed in other builds I have, so if anyone on here would be interested in getting involved, please contact me here, by PM or to my email address at info@bickerstaffguitars.co.uk. I don't have a decent website as of yet, its getting done, but if you would like to see some examples of what I build, please look for Bickerstaff Guitars on facebook.

Thanks for reading this.

Kind Regards

Pete

The essence of this is to have a 555 astable, which would supply a pulse to drive the display via an integrator to give you the appropriate speed of movement over the scale. Sound activation is a bit more tricky, but is from mic to amplifier to integrator and so on. Do you want a mechanical meter with a pointer going over a scale, or a LED bar?

I have already purchased the Gauge, and is currently on route. It is a 52mm LED type meter, with a digital numerical display showing RPM accompanied with an LED graduated bar around the circumference of the face.

OK, so if sound activated is a little tricky, I will give it a miss and just stick with a pulse type.

It shouldn't be that difficult to get to work on sound, velleman do a kit albeit only 5 LEDs long http://cpc.farnell.com/velleman-kit/mk1 ... dp/HK00725 but the principle ought to be the same. What are the electrical specs on your display?

Pauldf wrote:It shouldn't be that difficult to get to work on sound, velleman do a kit albeit only 5 LEDs long http://cpc.farnell.com/velleman-kit/mk1 ... dp/HK00725 but the principle ought to be the same. What are the electrical specs on your display?

I don't have any specs as yet. Hopefully it will come with some technical info. as soon as I receive it, I shall post any info on here.

I may be misunderstanding, but are you after lighting up one led from sound? Or is the graphic display? There is very simple single transistor circuit for sound to light that can glow leds. I use them for glowing an upside down cross on my guitar and it runs off a 9 v battery. I can draw this up at my studio tomorrow if this helps.

oram wrote:I may be misunderstanding, but are you after lighting up one led from sound? Or is the graphic display? There is very simple single transistor circuit for sound to light that can glow leds. I use them for glowing an upside down cross on my guitar and it runs off a 9 v battery. I can draw this up at my studio tomorrow if this helps.

That would be fantastic, Thanks.

I have received the tachometer, its a digital one, runs from 12v dc. Basically, all I want to do is to get it to cycle up and down on the meter when its switched on. Im going to use an A23 12v battery for this, but need the circuit to enable a signal to be sent to the tachometer as though it was a signal from the ignition coil or ignition module of a car. The guitar Im building is a tribute to a specific early 1970's Dodge Charger NASCAR race car, complete with exhausts, spark plugs valves and cylinder heads, loads of alloy and gadgets.

Do you have the spec of the tachometer?

Sorry, don't have time to draw one right now but, if you get a 2n2222 transistor, apply voltage to the collector, put the guitar signal onto the base and add the led from the emitter with relevant series resistor then to ground, i'm pretty sure this should work. I couldn't find the circuit i used at my studio, but I think form memory this is correct. I'll have a more in depth look on weds. I'm not the most knowledgeable electronics person in the world so maybe someone with alot more knowledge will want to check this.

From what I gathered he is wanting it to go up and down like a bar graph. Still need more info on the tacho, I was thinking it will react to an increase in voltage hence some sort of circuit that charges a small capacitor to drive an output as frequency increases will be good.

Here is a scan of the instructions that came with the tacho. Not sure if it gives the information needed but its all I have.