Electronics

U = U₁ + U_{2 etc.}

_{R = R1 + R2 etc. => The higer the resistance the higher teh voltage drop}  

_{=> Current ( I) = constant} 

U= constant

I_TOT = I_{1 +}I_{2 +} I_{3 etc.} 

\({1 \over R} = {1 \over R1} + {1 \over R2} + etc.\) ==> !!! based on this equation, the total resistance for all resistors connected in parallel is always smaller than the reistance of the smallest single resistor!!!

the product of voltage and the amount of charfe

=> W = U * Q   ===> Joule      W = P * t    ===> Ws Wattsekunden 

 \(P = { 1 \over t} = U * I\)=> Watt the product drop multiplied by the current flowing 

it must be transformed into heat, radiation or mechanical energy

=>Advantage: the supply voltage doesn't need to be constant => the systems continues to adjust itself until the Voltage UCD

two in series connected resistors (R1 and R2) are connected in parallel to another two (R3 and R4) which are also in series => All resistors habe the same value

===> the relation between the resistors is a definite one => the balanced condition is definied in => U_CD = 0 \(= {R1 \over R2} = {R3 \over R4}\)

two layers of metabolized plastic foil separated by a layer of electric material called dielectric

1. Switch open: nothing happen => the Capacitor  is in neutral condition

2. closing switch: electrons flow from the negative pole of teh battery onto the connected Capacitor  plate => until stable conditions are reached and the Capacitor is electrically charged ==> limited numer of electrons

3. Switch open: is open = frozen = teh Capacitor remains carged

4. Switch closed again: if teh lates of the loaded capacitor are directly connected to each other, teh pottential difference force s a curent from on to teh other plate until the Capacitor  is discharged as in step 1 

when a voltage is initially supplied to the Capacitor , a high current flows to the charge capacitator => current not constant because the more the plates become charged, the lower the electron flow from and to the Capacitor  = smaller the current  

=> the resistance of the Capacitor  under DC is not contstant => after switch on = very low => it increases with time up

Capacity C  (F) wie viel tatsächlich Platz hat => The amount of energy that can be stored in a capacitor ( between tw plattes) is calles capacity => Faraf (F) 

a) are of teh plate A

b) distanve between teh plates => smaller teh distance between the plates, the higher the capacity

c) the material between teh plates 

is a loss of energy over time, because they have an internal resistance => drops slowly to zero

\( {1 \over C} = {1 \over C1} +{1 \over C2} \)+ etc.

C Tot = C1 + C2 + etc.

There is a socalles electrical fiel exist between the plates => the field lines are from the positive to the negative

when electrons move

The capacitator is an electrical storage

No

The current arrives before the voltage is present at the plates, which means the voltage is delayed in relation to the current. If a sine wave AV is supplied to an ideal capacitor, the voltage is delayed compared to the current by 90 degrees

is an electrical energy storage device which produce a define voltage (cell voltage) by a chemical process

two different electrodes with different materials and a conducting liquid ( electrolyte) are required => the voltage depends on the material of the electrodes but not on the distance between the plates

battery => all elements that must be replaced after discharging => nicht wiederaufldbar

battery which can recharged after they have been depleted

1. Lead acid (small aircrafts) 

2. Nickel cadmium

3. Lithium 

in small aircraft => positive electrode: lead oxide negative electrode: pure lead => Max. 2.4 V => life: 1500 cycles

2.1 V for unloaded battery; cell voltage: 2.0 V => Normal 24 V im gesamten => 12 Batterien à 2.0 V max. charing: 2.4 V max. value before recharged: 1.8 V

Only with DC => connect must be to each other (plus to plus)

1. Constant current charge: sudden increase of voltage => If loading more than 2.4 V => water escape from battery => qunatity of water is reduced ==> destilled water must be refilled

=> high power consumption to charge the battery this way

2. Constant voltage charge: The more teh battery is charged, the more potential it develops => needs more time but the life time is longer and avoid gassing  

==> Constant voltage charge wird in der regel angewendet 

cannot normally work upside down, because there are small holes in the top of the battery to allow the gases to escape

6 V Battery ==> 7 V 

12 V Battery => 14 V

24V battery => 28 V for charge

no voltage limit but could runway => nominal voltage is 1.2 V ==> 20x 1.2 = 24 V ==> Charging with constant current => life 3000 cycles

thermal runways => if the temperatures reaches high values the separator melts and connect the positive and the negative plates => a short circuit and the battery explodes

Nickel Cadmium battery can used for high current loads and she NiCd battery can be discharged down to values nearly zero volts without being damaged