electricity for amateur radio. how much electricity is moving electricity is like punches how many...
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Electricity for Amateur Radio
How Much Electricity is MovingElectricity is like punches
How many electrons are moving?
How many punches are thrown?
The number of electrons flowing is the current – more current morePunches (T3A-03)
We have given you“Ample” warning
Current is measured in “Amperes”(T5A-01)
How Hard do You Punch?
We call it “Electromotive Force”
When electricity punches hardIt will give you quite a “Volt”
Volt
We Measure Electromotive Force in
Volts(T5A-11)
Power(Number of Punches X Force of the Punch)
More Punches – More Force
More Power
We measure electric power in Watts
because
Lots of punches and lots of force And you too will wonder “Watt hit Me?”(T5A-2)
What term describes the rate at which electricalEnergy is used?
Power(T5A-10)
Lets See If You Were Sleeping
(I’ve given you ample warning)
(This will give you a jolt)
Yup
(T5A-03)
(T5A-11)
(T5A-05)
One More
That’s Right
Electrical Power Leaves You Wondering “WATT” Hit Me.
The Power Pie
Power(Watts)
Voltage Current(Amperes)
(T5C-08)
If you have two pieces of the pieYou can always get the rest.
If you have two little pieces Multiply themTogether to get the big piece
Power = Voltage X Current
What If I Have the Big Piece and a Little Piece?
You divide the big piece by the littlePiece to get the other little piece.
Current = Power / Voltage
(T5C-11)
Now You Try It(T5C-10)
Which part of the pie do we have?
Checking the Answer
Voltage X Current = Power
12 X 2.5 = 30
Another Try
What do we have?
13.8 X 10 = 138
(T5C-09)
Another Factor In Electricity Flow
How Much Resistance is Holding Current Back
Resistance Has Units of Ohms
“Ohm” My How do I explainResistance?
Introducing the Ohm’s Law Pie
Did Somebody Say Lawyer?
Voltage
Current Resistance
As before – if you have two pieces of the pie you can get the third
If I Have the Two Little Pieces I Multiply to Get the Big Piece
(T5D-02)
If I Have a Big Piece and a Little Piece I divide the Big Piece by the
Little(T5D-01)
Lets Try You On It(T5D-03)
Answer
We Can Do It With Numbers
90 / 3 = 30 Ohms
Your Turn
Answer
12 / 1.5 = 8 Ohms
And Another
120 / 80 = 1.5 amperes
Your Turn
Answer
200 / 100 = 2 amperes
Try It With Two Little Pieces
We multiply two little pieces to get the big piece
2 X 0.5 = 1 Volt
Your Turn
Answer
10 X 1 = 10 Volts
Can You Duplicate These Answers?
(T5D-09)
Two Kinds of Electric CurrentVoltage is steadyAnd does not change
Current FlowsOne Way
Typical forBattery
Called Direct Current (DC)
Voltage goes up and downLike a waveCurrent Changes direction each time
Like the Outlet in your house
Called Alternating Current (AC)
Test Question
Did You Get It Right?
How About This One
Answer
The Voltage on Alternating Current Looks Like a Wave
Every Time the Voltage ChangesSign the Current Changes Direction
The number of times the current changes direction in a second is the frequency(in the U.S. its 60 times per second)
Resisting Flow in an AC Circuit has a Special Name
In a DC circuit we justCall it Resistance
It has units of Ohms
“Ohm My”
In an AC circuit we call it “Impedance”
It still has units of “Ohms”
See If You Can Get This.
Most VHF / UHF TrancieversUse Direct Current
That’s why you can hook them toA battery or plug into a cigarette lighter
Most run on 12 volts
Connecting a Mobile
Powering Your Base Station Radio
BatteryTender toKeep yourBattery charged Battery to Power
Your Radio
Can also run yourBase station withA plug in powersupply
Plugs into your wall outletPuts out DC power forYour radio.
Thoughts on Which Way to Go
• We favor the battery– If the power goes out – so does your power
supply
• Some People like power supplies because they fear children will get into batteries or that battery charging will generate hydrogen.
A $7 to $10 battery box and some ductTape will keep most kids out.
Slow charger with evenRemotely good ventilationAnd I just can’t see theHydrogen issue.
What if My Battery Still Goes Dead in an Emergency?
Power Supplies to Provide Nice Even Power
A Bit About Power Supplies
Your household current is AC
But your Radio runs on DC
How does that happen?
A special type of circuit called a “rectifier”
More on the Power Supply Miracle
My household current is 120 volts
My radio needs 12 volts
How did that happen?
The power supply includes a regulator to control the output voltage
Features on Power Supply And Other Places
Not All Power Supplies Are Created Equal
I can buy this for $40 bucks – a battery and charger will cost me $95
Check the spec. – How many amperes will it put out?
A base station draws around 12 to 16 amps when you transmit
Houston – we have a problem!
Don’t Get Snookered
Oh Cool Man!This one has 500 and is just$50
It has 500 what?
Watts – a measure of power
Watts = Voltage * Amperage
This supply is for a computer – its output voltage is about 5 volts – not 12 volts
Some supplies will express output in watts – if they do you have to check outputVoltage and then calculate the amperes
Suggestion
Don’t buy anything less than a 20 amp power supply.
But I’m Going to Run a Baofeng Handheld on Batteries.
Your radio is only good as long as the battery lasts
You can buy extra batteries
And the battery will fit in theCharger without the radio.
Hey I Found this Extra Large Battery on Amazon
Yes – but this bump means it won’t fit on most Baofeng Radios
You can whittle the offending bumps down with a dremel tool – U TubeVideos are available – if you want the hassle.
Here is a Case I Can Put 6 AAA batteries in
Not all batteries are rechargable!
Ni – Metal Hydride (Ni-MH)Are rechargable
Lithium Ion are rechargable(your cell phone and computers useThese)
The old carbon-zinc and alkalineBatteries are not.
Try the Questions
(This is a fancy rechargeable for base stations)
Some Things Are Easier for Electricity to Go Through
Things that let electricity go throughare called conductors.
Like the CopperWire in yourHouse(most metals are conductors)
Some Things are Hard
Things that stop electricSignals are insulators
(Things like plastic andglass are insulators)
Basic Electric Components
The resistor – it resists the flow of electricity
One Use for a Resistor
Variable resistor is called a potentiometer. It can be used control volume(Remember – the height of a wave or amplitude determines how much power is in the wave – resistors can controlAmplitude)
I Bet You Can Get This One
A potentiometer is a variable resistor - what do you think a potentiometer changes?
Another Component
The Capacitor is two electrical platesSeparated by an insulator. (T6A-05)
It can accumulate charges on thePlates and store energy in anElectric field. (T6A-04)
The capacity to store energy in anElectric field is called “Capacitance”(T5C-01)
Insulator
Two Plates Give You the Capacitance for Advertizing
Capacitors
Capacitors are very fair devices
In fact their capacitance is only measure in “Fair Ads” (Farads)
The Basic Unit of Capacitance is the Farad (T5C-02)
Another ComponentThe Inductor
They store energy in a magnetic field
The ability to store energy in a magneticfield is called “inductance” (T5C-03)
The type of component that storesenergy in a magnetic field is an inductor(T6A-06)
An Inductor is usually composed of aCoil of wire. (T6A-07)
What is the Name of the Duck?
The Basic Unit of InductanceIs the Henry! (T5C-04)
HenryHenry
Using Capacitors and Inductors Together
Inductors and CapacitorsWork together to let youTune an electric circuitTo a particular frequency
Of Course No Circuit Would Be Complete without This!
Do You Always Have to Flip Switches by Hand?
You can actually flip a switch with anelectromagnet
A switch controlled with an electromagnet isCalled a relay (T6D-02)
Don’t Blow a Fuse
Fuses Protect other electrical components from current overload (T6A-09)
Changing the Voltage
Transformers are used to increase or decrease voltage
120 volts is just too muchFor your computer.
The Semi-Conductor
A conductor will allow electricityTo go through
An insulator will not allowElectricity to go through
A semiconductor will allowElectricity to go through only underCertain conditions.
An example is a diode that allows electricity to flow in only oneDirection.
Which Way?
You can flow positive to negative
But you have to use electron terms
Anode + Cathode –(note they are in alphabetical order)
How Can You Tell Which End is Which
They put a band or Stripe on the Cathode Side
Checking to Make Sure Your Awake!
(T6B-06)
Your Turn
Did You Get It?
Stripe on the Cowthode Side
The Amazing Transistor
It is made of 3 layers of semiconductor material
It can use the voltage or current in one circuit to control what it will let current inAnother circuit do.
What can I do with that?
I can use a transistor to amplify a signalOr even turn it off all together.