Help With Electronics Project

It is not necessary to build any equalizer circuits at all. But if you want all four channels to have an equalizer then you will have to build four equalizers. Now it will get a little tricky to make four equalizers that must have identical equalizations. You could do this with a motorized potentiometer or a common voltage controlled potentiometer. It's all up to you about what you want.

As you have the knowledge I lack, could you please direct me to a site for a simple LED Flasher using a 555 timer.

Thanks

ROFLOL

As you have the knowledge I lack, could you please direct me to a site for a simple LED Flasher using a 555 timer.

Since you asked me so nicely, I'll point you to these sites for some inspiration...

http://wild-bohemian.com/electronics/flasher.html

http://www.electronics-project-design.com/LED-Flasher-Circuit.html

http://www.instructables.com/id/41-LED-Flasher-Circuit-using-555-IC/

http://www.simplecircuitdiagram.com/2009/05/20/led-flasher-circuit-using-555-ic/

http://www.eleccircuit.com/ic-555-led-flasher/

Most of these are a variation of the theme but you'll get the idea.

I thank you.

Easier to just hook up the LED to a DC source and just keep winking your eye.

Where have you been of late?

Your response was as helpful as a Skunk at a Picnic!

The concept is simple; During the day a German Shepherd is hard enough to spot out in the bush, even at 10 meters. Night time and 10 CM of snow makes a 60 KG puppy a stealth dog.

I wish to attach a LED device to each of my puppies. I just wish to keep an eye on them, as Porcupine encounters are a costly experience.

They think that a porcupine may be their best buddy (a rabbit named Stewie) is the same, just having a bad hair day.

The urban encounters are worse as a stop sign appears to be a mere suggestion. I might as well live in Quebec!

I am sure that you; the master of the F-16 Joystick, could direct me to a site that can give me a schematic of a sequential flash of a mere two LED's, based on a 555 IC chip.

Icarus

Well, this is clearly off-topic and I thought you were just kidding.

It would have been helpful if you had given this information up front. You would have had your answer straight away.

Unless you want to DIY, which I can't imagine why, there are already devices made that do just that. They are also used when you walk your dog, jogging, biking, etc., at night so you and your pet do not get hit by cars.

This is just an example of a few such devices.

So, not only do I know my F-16 joysticks, but I know a thing or two about winky-blinky, too. ;-)

Here are some graphic equaliser info;

http://www.ethanwiner.com/spectrum.html

http://picsicio.eu/keyword/parametric%20equalizer%20schematic/

http://damien.douxchamps.net/elec/param_eq/

If your looking for something with a bit more "Fidelity" then you might like to look at some of these amplifiers

This will give you at least 7watts a channel;

http://www.nxp.com/documents/data_sheet/TDA8947J.pdf

Or maybe this;

http://www.eleccircuit.com/4-channel-home-audio-amplifier-11-watt-using-ic-tda1554/

Mouser has 451 of NXP's tda8947 in stock (link), at only $1.97 each, or $1.39 each for a hundred. Wow! Yes, they're marked End of Life, NRND, ahem, but they should be available from Mouser for some time to come.

The tda8947 quad power-amplifier IC works with a single DC supply voltage, 9 to 26 volts. It's meant for use with bridge-tied-load, or BTL wiring, which is nice because no large AC-coupling speaker capacitors are needed. This gives you 2-channel stereo drive up to 50 watts, according to the datasheet. Speaking of the datasheet, it fails to show one the full BTL wiring, which is a speaker across pins 1 and 4, and a second one across 14 and 17.

The '8947 can deliver Io = 4A repetitive peak current into each speaker load. Let's imagine +10V on one output (wrt the quiescent voltage) and -10V on the other, that's 20V peak, which means 2.5A into an 8-ohm load. We can drive the speaker with ±20V and ±2.5A. Only a little over +22V of DC supply is required. The RMS power capability would be more than 0.5 * 20 * 2.5 = 25 watts. Per channel. For two only bucks, that's very nice indeed!

Yes, if you want to adjust the equalization for each channel, then you need to replicate the tone circuit four times.

Personally, I would be weary of that tone circuit. 20 dB of boost and cut on each control will most likely be difficult to live with in reality.

First, the idea of ±20dB of adjustment in the mid is ridiculous. ±5dB would be much more usable.

Second, without either simulating the circuit in Spice or building it and trying it, there is no way to really know if and where "flat" exists in the EQ. Many times circuits like this do not EQ flat when the controls are centered and sometimes it is impossible to get a flat response.

Third, the input to the EQ is unbuffered. This means that different input impedances will alter the tone circuit somewhat. Again, you need to simulate the circuit to see what is going to happen or add a buffer amp at the input and make it a truly active set of controls.

The pots should be linear. As Redfred noted, finding 4-ganged pots is not going to be easy.

You may want to keep looking for other circuits. This website is a good reference, too.

Tubes make some very nice sounding audio circuits. However, I would not recommend them for anyone starting to work in electronics. The high voltages required for most higher power tube amplifiers can quickly frustrate or harm a novice. Once the OP is comfortable with building solid state audio circuits then delving into the realm of tubes can be fun.

True. I wasn't recommending tubes, but the site is loaded with a lot of good fundamental knowledge which applies to all circuits.

If you are using this to drive a quad speaker system from a PC, laptop or MP3 player, why not just use the inbuilt graphic equalizer in the media player or MP3 player?