Hi,
Please excuse this posting if this is not the right place. I'd like to suggest some small changes to https://processing.org/tutorials/electronics/ --- in general, I'm trying to correct it so that I can use this [really very good] document as a general intro to 1st year engineering students who can benefit with some "fire in the belly" through experiments with electronics before they formally study electronics.
Original text is separated from suggested text by "==>". I avoided adding technical stuff such as units because I really value the general nature of this text.
Thanks,
phillip
- Second paragraph of Electricity - should state current is the rate of flow of charge per unit time
The amount of electrical energy that flows through a point is the current.
==>
The amount of electrical charge per second that flows through a point is the current.
- Last paragraph of Electricity - no longer claim that a transformer can produce DC (it cannot)
Depending on your country, the AC power coming into your home is between 100 and 240 volts. Most home appliances use AC current to operate, but some use a transformer to convert the higher-potential AC energy into DC current at smaller voltages. The black plastic boxes (a k a power bricks, power adapters, wall warts) that are used to power laptops or mobile phones are transformers. Most desktop computers have an internal power supply with a transformer to convert the AC signal to the 12-volt and 5-volt DC signals necessary to run the internal electronics. Low voltages are generally safer than high voltages, but it’s the amount of current (amps) that makes electricity dangerous.
==>
Depending on your country, the AC power source coming into your home is between 100 and 240 volts. Most home appliances can directly use AC current to operate, but some use a power supply to convert the higher-potential AC current into DC current at smaller voltages. A common example of this type of power supply are the black plastic boxes (a k a power bricks, power adapters, wall warts) that are used to power laptops or mobile phones from the home AC power source. Most desktop computers have an internal power supply to convert the AC source to the 12-volt and 5-volt DC supply necessary to run the internal electronics. Low voltages are generally safer than high voltages, but it’s the amount of current (amps) that makes electricity dangerous.
- Capacitor - correctly state how current flow leads to charge increase or decrease in an [ideal] capacitor. Also now state that electrons are charge.
A capacitor stores electrons; it stores electrical charge when current is applied, and it releases charge (discharges) when the current is removed.
==>
A capacitor stores electrons i.e. electrical charge; it gains charge when current flows in, and it releases charge (discharges) when the current flows out.
- Programmable I/O boards - suggest mention that communications becomes easier
These boards typically have components to regulate power to protect the microcontroller and a USB or RS-232 serial port to make it easy to attach cables.
==>
These boards typically have components to regulate power to protect the microcontroller and a USB or RS-232 serial port connector to make it easy to attach cables for communication.
- Sensors and Communication - figure right hand side waveform is described as "digital" when it is still continuous. Trying not to be [too] pedantic but suggest changing
Digital signal
==>
Discretised signal
- Controlling physical media - paragraph 1 - would like to introduce DACs before PWMs that emulate analogue output, and also mention smoothing. Note that the DAC sentence refers to the discretised waveform noted in the previous suggestion. Added a final sentence to include a physical world example that might help.
Actuators are devices that act on the physical world. Different types of actuators can create light, motion, heat, and magnetic fields. The digital output pin on a microcontroller can set a voltage of 0 or 5 volts. This value can be used to turn a light or motor on or off, but finer control over brightness and speed requires using a technique called pulse-width modulation (PWM). This is turning a digital output ON and OFF very quickly to simulate values between 0 and 5 volts. If the output is 0 volts for 90% of the time and 5 volts for 10%, this is called a 10% duty cycle. It emulates an analog voltage of 0.5 volts. An 80% duty cycle emulates a 4-volt signal:
<
>
The PWM technique can be used to dim a light, run a motor at a slow speed, and control the frequency of a tone through a speaker.
==>
Actuators are devices that act on the physical world. Different types of actuators can create light, motion, heat, and magnetic fields. The digital output pin on a microcontroller can be set to a voltage of 0 or 5 volts. This value can be used to turn a light or motor on or off, but finer control over brightness and speed requires an analog output. By using a digital to analog converter (DAC), a discretized signal can be directly generated as illustrated in the previous figure. If desired, some smoothing can be added to obtain the desired analog signal. When a DAC is not available or not justified in terms of cost or conversion speed, another approach is to use a technique called pulse-width modulation (PWM). This is turning a digital output ON and OFF very quickly to simulate values between 0 and 5 volts. If the output is 0 volts for 90% of the time and 5 volts for 10%, this is called a 10% duty cycle. Following smoothing, it emulates an analog voltage of 0.5 volts. An 80% duty cycle with smoothing emulates a 4-volt signal:
<
>
The PWM technique can be used to dim a light, run a motor at a slow speed, and control the frequency of a tone through a speaker. In some applications, any necessary smoothing is obtained for free e.g. the inertia in a motor can average out the PWM duty cycle and result in smooth motion.
Hi,
Please excuse this posting if this is not the right place. I'd like to suggest some small changes to https://processing.org/tutorials/electronics/ --- in general, I'm trying to correct it so that I can use this [really very good] document as a general intro to 1st year engineering students who can benefit with some "fire in the belly" through experiments with electronics before they formally study electronics.
Original text is separated from suggested text by "==>". I avoided adding technical stuff such as units because I really value the general nature of this text.
Thanks,
phillip
The amount of electrical energy that flows through a point is the current.
==>
The amount of electrical charge per second that flows through a point is the current.
Depending on your country, the AC power coming into your home is between 100 and 240 volts. Most home appliances use AC current to operate, but some use a transformer to convert the higher-potential AC energy into DC current at smaller voltages. The black plastic boxes (a k a power bricks, power adapters, wall warts) that are used to power laptops or mobile phones are transformers. Most desktop computers have an internal power supply with a transformer to convert the AC signal to the 12-volt and 5-volt DC signals necessary to run the internal electronics. Low voltages are generally safer than high voltages, but it’s the amount of current (amps) that makes electricity dangerous.
==>
Depending on your country, the AC power source coming into your home is between 100 and 240 volts. Most home appliances can directly use AC current to operate, but some use a power supply to convert the higher-potential AC current into DC current at smaller voltages. A common example of this type of power supply are the black plastic boxes (a k a power bricks, power adapters, wall warts) that are used to power laptops or mobile phones from the home AC power source. Most desktop computers have an internal power supply to convert the AC source to the 12-volt and 5-volt DC supply necessary to run the internal electronics. Low voltages are generally safer than high voltages, but it’s the amount of current (amps) that makes electricity dangerous.
A capacitor stores electrons; it stores electrical charge when current is applied, and it releases charge (discharges) when the current is removed.
==>
A capacitor stores electrons i.e. electrical charge; it gains charge when current flows in, and it releases charge (discharges) when the current flows out.
These boards typically have components to regulate power to protect the microcontroller and a USB or RS-232 serial port to make it easy to attach cables.
==>
These boards typically have components to regulate power to protect the microcontroller and a USB or RS-232 serial port connector to make it easy to attach cables for communication.
Digital signal
==>
Discretised signal
Actuators are devices that act on the physical world. Different types of actuators can create light, motion, heat, and magnetic fields. The digital output pin on a microcontroller can set a voltage of 0 or 5 volts. This value can be used to turn a light or motor on or off, but finer control over brightness and speed requires using a technique called pulse-width modulation (PWM). This is turning a digital output ON and OFF very quickly to simulate values between 0 and 5 volts. If the output is 0 volts for 90% of the time and 5 volts for 10%, this is called a 10% duty cycle. It emulates an analog voltage of 0.5 volts. An 80% duty cycle emulates a 4-volt signal:
><
The PWM technique can be used to dim a light, run a motor at a slow speed, and control the frequency of a tone through a speaker.
==>
Actuators are devices that act on the physical world. Different types of actuators can create light, motion, heat, and magnetic fields. The digital output pin on a microcontroller can be set to a voltage of 0 or 5 volts. This value can be used to turn a light or motor on or off, but finer control over brightness and speed requires an analog output. By using a digital to analog converter (DAC), a discretized signal can be directly generated as illustrated in the previous figure. If desired, some smoothing can be added to obtain the desired analog signal. When a DAC is not available or not justified in terms of cost or conversion speed, another approach is to use a technique called pulse-width modulation (PWM). This is turning a digital output ON and OFF very quickly to simulate values between 0 and 5 volts. If the output is 0 volts for 90% of the time and 5 volts for 10%, this is called a 10% duty cycle. Following smoothing, it emulates an analog voltage of 0.5 volts. An 80% duty cycle with smoothing emulates a 4-volt signal:
><
The PWM technique can be used to dim a light, run a motor at a slow speed, and control the frequency of a tone through a speaker. In some applications, any necessary smoothing is obtained for free e.g. the inertia in a motor can average out the PWM duty cycle and result in smooth motion.