Changes between Version 1 and Version 2 of ElectricalIntroduction
- Timestamp:
- Aug 20, 2017, 9:47:02 PM (8 years ago)
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ElectricalIntroduction
v1 v2 1 == Electrical Overview == 2 1 3 Robots need power and most robots draw their power from an electrical battery. 2 4 3 == Batteries==5 === Batteries === 4 6 5 7 Batteries have two electrical terminals and chemicals between them. The terminals and chemicals are chosen so that they can react chemically, for the reaction to work, one terminal needs to lose electrons and the other needs to gain them. So when electrons can move from one terminal to the other, the chemical reaction proceeds. Normally, the battery terminals are separated by air which resists the flow of electrons, but if the terminals are connected together with a wire or other material that allows electrons to flow, the reaction proceeds as long as electrons flow from one terminal to the other. … … 34 36 * What happened: the two jumper wires and the wire filament in the bulb provide a path for the electrons to flow from the negative battery terminal to the positive battery terminal, creating a complete circuit. As the electrons flow through the circuit, the resistance they encounter as they push their way through the bulb's filament cause it to get hot, glow, and emit light. 35 37 36 The power used to light the light or turn a motor is is measured in [https://en.wikipedia.org/wiki/Watt Watts] (named after [https://en.wikipedia.org/wiki/James_Watt James Watt]) and is a function of voltage (the pressure from the battery) and current (the number of electrons flowing); specifically [[[ Watts = Amps * Volts ]]]. 38 The power used to light the light or turn a motor is is measured in [https://en.wikipedia.org/wiki/Watt Watts] (named after [https://en.wikipedia.org/wiki/James_Watt James Watt]) and is a function of voltage (the pressure from the battery) and current (the number of electrons flowing); specifically 39 {{{ Watts = Amps * Volts }}} 37 40 38 41 * Exercise: use a multimeter to measure the current flowing through the light bulb circuit … … 68 71 69 72 Our circuits have consisted of a battery, wires to carry electrons to and through a load like a bulb or motor. The load presents resistance to the flow of electrons and when the pressure (voltage) of the battery pushes the electrons through the load, some of that work is converted into other forms of work energy (heat, light, rotational force, etc.). The amount of work done by the electrons flowing is proportional to the resistance presented: 73 {{{ 70 74 Watts = Volts * Amps 71 75 Volts = Amps * Resistance 72 76 Watts = Amps * Amps * Resistance 77 }}} 73 78 74 79 Resistance is measured in [https://en.wikipedia.org/wiki/Ohm Ohms] (named after [https://en.wikipedia.org/wiki/Georg_Ohm Georg Ohm). The relationship between voltage, current, and resistance is fixed (i.e. the amount of current that flows is determined by the pressure being applied and the resistance to that pressure) and is defined as "Ohms Law":
