Difference between revisions of "ElectronicsClass"

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==Digital Logic==
==Digital Logic==
* AND  C = A & B
* OR  C = A | B
* NOT  C  = !A
* NOR C = !(A|B)
* NAND C = !(A&B)
* MUX C = select A(n) based on B(n)


Revision as of 15:51, 16 June 2010

Electronics Class

This class is targeted at the beginner who wants to learn electronics. It would make a fine prerequisite to the Microcontroller Course or the HAMClass


[[1]] wm greek fire [[2]] needs bolts

Required Materials

  • Soldering Iron (25-30w)
  • Solder ( 22ga )
  • Bread Board ( or AshClassBoard )
  • wire 24ga
  • 30ga solid core wire
  • Resistors 10kohm
  • variable resistor 10kohm linear
  • switch [[3]]
  • leds (various)
  • capacitor 470uf (ish) [[4]]
  • pn2222 transistor
  • lm386 audio amplifier ic
  • 1/8 male phono jack
Read The Fine Data Sheet:  They hide secrets in the documentation.


  • Measured in watts (usally)
* .01w laser pointer
* .25w cell phone
* 1w 
* 15w car stereo
* 25w soldering iron
* 100w light bulb
* 1500w hair dryer
* 200 horsepower (750w/hp)
* 3 tons of Air conditioner capacity (3.5kw/ton)
  • The notion of instant work
  • Energy or work is expressed in joules (watt*second). Or perhaps (Kw*H)
  • Power(watts) = Current (Amps) * Volts


There are many like it but this one is mine.
  • Naming of parts
    • metering modes
      • restistance - Ohms of resistance
      • voltage - Volts
      • Current - Amps/Milliamps - check the leads
      • diode check - see [Diodes]
    • leads - plugged into the right ports?
  • Continuity testing
    • set the meter to the lowest resistance mode (200ohms or auto resistance)
    • reads "off scale" when the leads are unconnected, this is an open circuit
    • firmly touch leads together
    • reads near 0 if the leads are crossed
  • Voltage testing
    • set meter to 20Vdc or VautoDC
    • touch leads to metered points
    • the reading on the meter is the difference in voltages between the leads


Hold the cold end.

Soldering ( for our purposes ) is the process of joining electrical contacts with a low melting point metal to make a mechanically and electrically strong connection.

  • Restrain long hair/clothing/jewelry.
  • Clean both parts of waxes, oils or debris.
  • Mechanically fit connections together
  • Clean and wet the iron
  • Heat both parts until hot
  • Apply just enough solder to wet the contact surfaces
  • Wait for the connection to shine smoothly
  • remove the iron an test the connection
    • the meter should find near 0 ohms of resistance between the two parts even when mechanically stressed.
    • the meter should read "off scale" to everything that should be isolated


  • use the continuity meter to diagram the electrical layout of the switch.
  • solder switch to the board.
  • test under power with meter voltage setting


The basic wire is a pipe through which electrons can flow from the lowest voltage side to the highest (conventional current) up to the physical limits of the wire.

  • Current limit via wire gauge [5]
  • Voltage limit via insulation.
  • Magnetic and Electric fields surround an energized wire (what?!)
  • And wire will respond with current when moved through magnetic flux
Get this out of the way early (and often)
  • turn off the switch
  • Solder the 30ga wire ends on to the lab 0 area
  • stow fingers away from wire
  • turn on switch


Not like the NYC variety

Resistors impede the flow of electrons across them; usually to protect components from excessive current.


  • solder resistors, meter and record;
  • compare to ohms law math



  • a favorite led [6]
  • LED ( Light emitting diode ) are diodes with a clear case.
  • electrons only permitted to flow in one direction: cathode to anode
    • there are exceptions [diode breakdown voltage]
  • discontinuous IV curve
  • diode logic
  • the cathode is marked
  • the diode check function of the meter can reveal the correct polarity of a mystery diode with a suspect cathode mark.

Light Emitting Diode

  • the short lead is the cathode
  • LED's need current limiting (see BlueSmokeLab)
  • solder in 1kOhm resistor for the led , although you may use another if you can justify the value
  • Solder in the LED, with the short lead towards the ground.


Printed Circuits


470uf electrolytic cap

Capt.png wikipedia capacitor



  • SPDT - single pole dual throw
  • DPST - dual pole single throw
  • 4P10T - ???
- Map this mystery switchLab
Electromechanical relay is a switch that's controlled electrically.


  • Easy to design for
  • debugging (listen for satisfying click)
  • excelent isolation
  • high power control/$


  • high drive current (mostly)
  • noisy (mostly)
  • slow
  • moving parts (eeew)

a typical relay - map this mystery relay lab


PN2222 N channel transistor

little amplifierlab

  • class A amp
  • DC blocking caps
  • bias resistors
  • fixed gain
  • inverted waveform

Digital Logic

  • AND C = A & B
  • OR C = A | B
  • NOT C = !A
  • NOR C = !(A|B)
  • NAND C = !(A&B)
  • MUX C = select A(n) based on B(n)


LM386 Audio Amplifier [7]