From 4a95719d58a708ad55b1389631d6339047f786a0 Mon Sep 17 00:00:00 2001 From: standenboy Date: Fri, 15 Dec 2023 10:19:20 +0000 Subject: added existing work --- electronics/notes/1 | 29 +++++++++++++++++++++++++++++ electronics/notes/2 | 38 ++++++++++++++++++++++++++++++++++++++ electronics/notes/3 | 15 +++++++++++++++ electronics/notes/4 | 10 ++++++++++ electronics/notes/5 | 24 ++++++++++++++++++++++++ 5 files changed, 116 insertions(+) create mode 100755 electronics/notes/1 create mode 100755 electronics/notes/2 create mode 100755 electronics/notes/3 create mode 100755 electronics/notes/4 create mode 100755 electronics/notes/5 (limited to 'electronics/notes') diff --git a/electronics/notes/1 b/electronics/notes/1 new file mode 100755 index 0000000..c6f9208 --- /dev/null +++ b/electronics/notes/1 @@ -0,0 +1,29 @@ +really simple first lesson, talked about what a current actually is + +also talked about basics of circuits: +eg: + cell long line is posative short line negatie, remeber that a - is short + current flows from posative to negative but electrons themselfs flow negative to posative. + thats being caused by people assuming thing flow one way before mesuring them + conventional current reffers to there posative to negative NOT THE FLOW OF ELECTRONS + +we also did some practical, where we built a circuit with a bulb +we learnt how to use the multi meters +how to: + put one input into the com (common port) and another goes into the coresponding wire you want to use + 10 amp (probably never used) is the far left + mamps is the second from left + common is third from left + voltage is fouth + turn the thing to where it is needed, a wavey line is ac, straight is dc + if working with low volts/amps turn it down to mvolts or mamps + +we also learnt more about the rest of the course +notable bits: + we will start course work in second year + first few weeks is just gonna be gcse recap + then something about digital logic, sounds fun + sheet about that in folder + we will have done some of the second year stuff in year 1 to give us time for course work + +we also joined the teams thing diff --git a/electronics/notes/2 b/electronics/notes/2 new file mode 100755 index 0000000..7a81de2 --- /dev/null +++ b/electronics/notes/2 @@ -0,0 +1,38 @@ +use these to convert to the standard unit +ie: + 1km = 1 x 1000 meter + 1mV = 1 / 1000 volts + +G = giga = x 1,000,000,000 = x10^9 +M = mega = x 1,000,000 = x10^6 +k = kilo = x 1000 = x10^3 +m = milli = / 1000 = x10^-3 +u (funny u (mu)) = micro = / 1,000,000 = x10^-6 +n = nano = / 1,000,000,000 = x10^-9 +p = pico = / 1,000,000,000,000 = x10^-12 + +you can do the inverse of those to convert to a more reasonable scale +ie: + 120,000V = 12kV + 0.15A = 150mA + +first half of the lesson was learning those and touching up on standard form + +second half we are going over current and voltage + +current is the rate of flow of charge, to find the current, i = q/t with i being current, q is culombs and t is time +AMETERS GO IN SERIS + +voltage is the energy tranfered per unit of charge +v = e/q with v being volts, e being energy, and q being culombs +VOLTMETER GO IN PARRALEL + +later on we are doing practical, mesuring voltage with circuit with a bulb or a resistor +plotted the results on a graph, my resistor graph was perfectly liner +and my bulb graph is more similar to a cubic graph + - + / +- +kind of like that + +we looked at a bit of resistance at the end, worksheet work (BRING IT TO THE NEXT LESSON) diff --git a/electronics/notes/3 b/electronics/notes/3 new file mode 100755 index 0000000..7152b8f --- /dev/null +++ b/electronics/notes/3 @@ -0,0 +1,15 @@ +((1/r)+(1/r)+(1/r))^-1 +that is the total resistance of the circuit if it is in parralel +we did this cool practical with a box to see where resistors are +when you have resistors in series the supply voltage is shared un evenly across the resistors +the sum of the voltages across the resistor will add up to the voltage from the power suply +if the resistors are of the same resistance the voltage will be an even split +greater voltage will go across the larger resistor +each component has the has an equal proportion of the total voltage compared to the proportion that the resistor is to the total voltage + +(r1 / rt) = the proportion in restance + +voltage across a componet = (r1 / rt) x VoltageTotal + +kirchoff's first law, is that the current in all parralel branches adds up to the total current +his second law is that the sum of the energy in point equals the sum of potential differences around any loop of a circuit diff --git a/electronics/notes/4 b/electronics/notes/4 new file mode 100755 index 0000000..a6d1ca7 --- /dev/null +++ b/electronics/notes/4 @@ -0,0 +1,10 @@ +the sum of currents into a node = the sum of currents exiting the node - kirchoffs first law +the sum of the emf equals the sum of the potential differences across a loop - kirchoffs second law + +the emf is the voltage across a power supply + +remember that when a wire splits into 2 parralel branches its current splits while the voltage stays the same + +this is because voltage is a mesure of energy per unit of charge, which wouldn't change because each electron has the same charge. +the current splits because its a way of messuring the amount of charge flowing + diff --git a/electronics/notes/5 b/electronics/notes/5 new file mode 100755 index 0000000..a962531 --- /dev/null +++ b/electronics/notes/5 @@ -0,0 +1,24 @@ +mosfet's +(metal oxide semiconducting feild effect transistor) +voltage controled device +has a: +drain equivilant to the collector on a transistor +gate the base +source the emmiter + +no current can flow into the gate + +its just a new kind of transistor for the most part +differences between transistor: + when it is on, it still conducts slightly (about 0.4V) + this is because it has a slight resistance, whereas a transistor does not + the small resistance it has is given the name Rdson (something about resistance when on (r d s on)) + there is a formula for this in the formula sheet + + a mosfet will start to conduct when the input voltage is 3V unless the question says otherwise + + when ploting a graph of a mosfet, with Vin and I at the drain (Id) the gradient of that line is called gm + Id = gm * (Vin - 3) + gm is called the transconductance + + the gm and rdson are propertys of the mosfet -- cgit v1.2.3