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    How did u get started in electronics?

    I was taught the basics by my father, When I was young  (8 or 9) he had a Ham Radio rig. I started with Tubes and my first active device project was a triode AM radio.  It was basicly a crystal radio with a triode acting as a amplifer to drive a speaker. As I remember, it was not all that loud...
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    motor driver L298 help

    Indulis, You are correct, the fixed frequency method works because of the inductance, or more correctly, the impedance, of the whole motor.  At a low frequency, Lets say 0hz – DC,  the motor sees the full power as current through the windings and thus produces a magnetic field resulting in...
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    Touch sensitive pad

    Tkjaz,     Looks to be about $3.00 us. Digikey Link: http://dkc3.digikey.com/PDF/T063/1898.pdf Might be able to find them cheaper from other sources. -Mike
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    Touch sensitive pad

    Check out a product called Q-Prox http://www.qprox.com/products/touch.php Sensors can pick up finger touches through thick plexy. Edge light your plexy and etch symbols into it for a amazing display/ control panel! -Mike
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    Where's the internal speaker of a computer located?

    it's just a speaker.  Usually 8 Ohms and less than a watt. here is a typical one :  http://www.mycableshop.com/sku/PCCASESPEAKER.htm If you want to mount it outside just extend the red and black wires outside the case.  But speakers sound louder if they are mounted in a box so you might want to...
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    Dual Displays Project

    If you want a "Way Cool" challenge. Connect a row of SMT leds on a stick and spin it. Then using accurate timing, draw the next number in mid air.  (Put one digit on the left of center and the other on right of center) Hows that for wizzy bang ? -Mike
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    Where's the internal speaker of a computer located?

    It's inside. Open up the box, you will see it. From Q-basic, I don't think so.  The external speakers are usually run off a sound card, the internal speaker was rarely connected to an external jack.  You can do that if you wish, just don't use amplified speakers unless you knock the voltage on...
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    Dual Displays Project

    how big of a TFT display? Are you talking about a little 2 line by 16 char type of a larger Computer flat screen type? And how large is the 7 Segment display? I guess it comes down to what you are trying to prove.  If you want to show that you can build the circuit then skip the TFT and just...
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    CRO

    OH! I think I get it.  He wants to put the scope into the X-Y mode (Ch1 on X ch2 onY) and use the PIC to control the signals to DRAW a game on the screen. If it's a 30Mhz it must be a fair machine so I am guessing it also has a Z input on the back that can be used to control the intensity of the...
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    help..

    The 556 chip is very similar to a pair of 555 timers. On the left side of the chip the Cap and resistors are used to set a frequency for the signal. Usually this frequency is not needed to be exact.  Most servos are forgiving but it should be around three thousand pulses per a second or 3 Khz...
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    We would like to use a Basic Micro Or PIC to turn on and off 51 LED

    Try using a (MosFet N-Channel Enhancement mode) to actually switch the LEDs on and off. Many fets can be connected directly to a microcontroller. (NOT all, check your datasheet) For 50 of them, There may be a PIC that has 44 I/O pins but I'd suggest a different method. Look into "Serial In /...
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    help..

    Zoinks, that’s a lot of questions. All right 1 at a time:     Touch sensors.  A FET touch sensor is the same thing used on those lamps that you touch to change the brightness.  IT can be done with any high gain amp.  If you have ever touched the input to an audio system and heard that loud hum...
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    Heatsink Surface Area

    Paul_J,  That’s like the test I was talking about. We did it (2 decades ago) in a class on microprocessors of all things!  It was just a side note where the instructor demonstrated how heat sinks have different abilities.  He used the Soldering iron as a fixed and constant heat source.  But he...
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    Heatsink Surface Area

    What type of metal is important. (Al is most common) Also the shape is important to some degree. If the part is mounted at one end of a long sink the wattage will be lower than if the part were mounted in the middle of the same sink. I don't know of any actual 'formula' to convert the shape...
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    help..

    When you say Miniature, I assume that you mean smaller than human sized? If that is true, the sensors depend on what you expect to ‘trigger’ the doors to open. The classics are:           Photo transistor:  When exposed to light it will conduct.  By covering it (making it dark) it will conduct...
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    circuit breaker

    my best guess?  Try about a 32-34ga wire. Id suggest you build a rig with 2 terminals that you can wrap the wire around and then cover with a shield.  Wire going vapor can be dangerous. for a few bucks you can buy a circuit breaker. You can also use a 'shunt' resistor, a RS flipflop and a...
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    Networks

    A circuit sketch would help but I think you are confusing current flow with polarity. While the polarity of the current does indicate the direction of the flow, the magnitude Of the current is always a positive number.  3Amps * 1V = 3watts.  -3amps * 1v = 3watts Not Negative 3 watts.  A negative...
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    A simple transistor switch for an LED light.

    Mike, HI!  Well transistor theory is a deep subject. I have one textbook that focuses on just PNP/NPN type transistors.  It’s about 2” thick. The SWITCHING method is thankfully the easer ways to use a transistor. The Emitter (the arrow on the schematic symbol) needs to connect to ground. The...
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    Choosing the right equipment wire?

    Great, Thanks! -Mike
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    Transistor Question

    thats what I said. IF you reverse bias test the transistors, the COllector to base will be LOWER than the Emitter Base.  But the test COULD destroy some diodes. SHesh, I not wrong ALL the time. -Mike
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