Kila, the Magic Husky's Ham Radio College featuring Kila and her Trusty Sidekick, Ben

Kila, the Magic Husky's Ham Radio College

featuring Kila and her Trusty Sidekick, Ben

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Episode 4 -- aired on March 7, 2016 -- Interview with Solar Scott and the introduction to Alternating Current and Reading Schematics

Listen to the episode 54.9 MB MP3

Solar Power

How to Install your own solar power system, with guest Solar Scott who has been installing photovoltaic (solar) systems in Lake county for over 15 years.
Off Grid and Grid Tie systems -- The "Grid" here refers to PG&E Power Grid. A "Grid Tie" installation uses PG&E's power lines as a giant battery for nightimes and cloudy days. Off Grid systems use your own batteries instead.

First, figure out how much power you need throughout a single day

If you've got a PG&E bill, you can just see how many watts used in a single day
If not, figure out how many watts each device uses, and:
- Multiply by the number of hours in a day to find total Watt-hours in a day, then
- Divide by the actual percentage of each day during which you expect to use it.
Assume that your panels will see the sun for around 6 hours per day, so divide by six to see how many total wants of panels you'll need.
Multiply by 4 to 7 days to account for cloudy days. Or maybe only 2 days' of batteries and buy a generator to top them off when it's cloudy for a long time.

For example, If I have the folling appliances:

Appliance	Current at 120 Volts	Watts used in 1 hour	% used during 24 hours	Watts in a day
Mini Fridge	2 Amps	2 × 120 = 240	50% of 240 × 24	2880 watts
Microwave Oven	1800 watts ÷ 120 volts	1800	5% of 1800 × 24	2160 Watts
Television	200 watts ÷ 120 volts	200	33% of 200 × 24	1600 watts
Laptop Charger	85 watts ÷ 120 volts	85	100% of 85 × 24	2040 watts
Water Pump	1/2 HP = .5 × 746 ÷ 120 volts	373	12.5% of 373 × 24	108 watts
LED Lights	70 watts ÷ 120 volts	7 watts × 10 lights = 70	50% of 70 × 24	840 watts

All of those things together add up to 9628 watts per day. Let's round it up to 10kw per day. That's how much we need in panels.
If we use standard 300 watt panels and we can rely on approximately 6 hours per day of light, then we need 10kw ÷ 6 = 1,666 watts or 6 panels. (300 watts × 6 panels = 1800 watts, which is slightly > 1,666)
Now, we need to get batteries which those 6 panels can charge. If we buy a generator for cold weeks, then just 4 days' clouds = 40kw of batteries.
Obviously, your milage may vary. :o)

Passive AC Electronics

AC vs DC
RMS vs Peak vs Peak to peak
household electrical current
Residential Electrical Wire Colors
The National Electrical Code
Distribution Electricity using high tension power lines causes an extra three leukimia deaths per every 100,000 people.
- But if we didn't distribute electricity, we'd all have to have our own power plants. How would we do that? Who would pay for it? It'll take some time to transition to batteries and solar panels and windmills (for those of us who have the property). In the meanwhile, generators would produce so much polution that we'd all suffocate.
- What if nobody used any electricity at all? Then we'd have a big food distribution problem; without electricity, we'd have no electric refridgeration. Granted, you can store your food in a big hole in the ground (again, if you have the land). But then we'd still need to power the trucks and the world is running out of cheap fossil fuel.

Reading Electronic Schematics

The Technician Class License Exam Question Pool includes a dozen questions related to drawing and reading "electrical circuit schematic diagrams".
A Schematic is a picture of where electricity flows in a circuit. Various power sources, loads and electric components are represented by particular scribbles connected by lines, representing wires in a drawing.
By convention, all lines connecting elements on a schematic are drawn straight and only vertically or horizontally, with L shapped bends, as needed.
Whenever on a schematic, two lines cross, they either represent wires which connect with one another, or wires whch DO NOT connect. If the wires are supposed to connect, a filled in circle is put at the intersection of the lines. If the wires do not connect, either no filled-in circle is drawn or, less ambiguously, one of the lines, as it intersects the other, is replaced with a 180 degree arc or open half-circle to denote a "hop" over the other wire so as to show them not connecting, such as you can see in this schematic of a simple audio amplifier:
Oftentimes, since a large circuit will have many different components connected across the DC Power Supply's (-) and (+) connections, we often will represent the positive DC voltage, or "Signal Input" as nothing more than a tiny open circle, such as the pair of them on the left side in figure T1.
Very often, in AC or DC circuits, the chassis of the equipment will be connected to (or considered to be) "Ground". That is, the word, "Ground" here refers to a convention that the minus DC voltage is connected to so many different parts of the schematic, that rather than connect them all together with lines on the page, we just use the symbol shown in T1 (5) to imply that all those connections are connected together with the minus power supply and probably also the chassis of the equipment. This is to prevent static electricity from interacting with the circuit.
The schematic above also shows both ground as well as +12v and -12v. What is happening here is that the power supply has two different 12 volt DC sources of power available to this circuit. The plus of one of them is connected to ground and the minus of the other is, also.
The Ground symbol in this schematic is different than the one in the other three examples, T1 through T3. This is actually a ground symbol, the one labelled chassis ground in T1, T2 and T3 is also a ground but more modern; it referrs to the metal case in which the circuit is housed. The symbol in this schematic below R5, at one side of the Audio In, below R7 and K1 (which is a speaker, a device for converting low level AC electricity into sound that you can hear) is a ground symbol more widely used and, in the old days, meant an actual metal rod 8 feet long, stuck into the actual dirt outside, with a wire coming into the house. We often connect circiuts (especially those of transmitters and receivers connected to big tall antennas outside) to ground so that the kinds of stray static electricity that cause lightning won't hurt our equipment. They exist all the time, in small enough amounts to ruin expensive radios but not large enough to actually cause lightning you can see outside.
- Figure T1 -- A battery charger
- The items below outlined in Bold represent symbols which appear in the Technician Class Exam Question Pool. That is, if you learn to recognize all the symbols in bold, that represents another 12 questions in the pool of 470 to which you have the answer.
  1. Resistor
  2. NPN Transistor
    - NPN = "Never Points iN"
    - PNP = "Proudly iN Pounts"
  3. Incandescent Light
  4. Battery
  5. Chassis Ground
- Figure T2 -- DC Power Supply
  1. Power Plug
  2. Fuse
  3. Single-pole single-throw Switch
  4. Transformer
  5. Diode
  6. Capacitor
  7. Resistor
  8. Light Emitting Diode (LED)
  9. Potentiometer or Variable Resistor
  10. Zener Diode
- Figure T3 -- Output circuit of a transmitter
  1. Input to this stage of the circuit
  2. Variable Capacitor
  3. Variable Inductor
  4. Antenna
Resources

If I've made any mistakes, please Call me or email Kila or you can call us directly at (707) 413-6435.
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