Electronic and mechanical systems
Inputs, outputs and processes in systems used by designers
Selecting components
Since electronics and mechanical systems were first developed, the speed at which new materials, techniques and processes have been developed has been rapid and revolutionary. Scientists, designers and engineers have worked to invent and improve systems that impact lives.
When designing a A number of parts working together to fulfil a complete function., electronic or mechanical, it is important to know what a product is capable of doing - this would be the The part of a circuit that acts, eg lights up or makes a sound..
Systems are often designed using a system block diagram that considers the The series of events that makes a system. of a system. How the system will work is the A series of actions that are usually followed in an order. and the The place where a force enters a system. is the part of the system that enables the process to start happening.
Selecting A part that when put together makes a product. to use in the production of electronic and mechanical products is complex, and these should be carefully chosen to ensure a product is Practical and useful. . There are a range of different A device that measures a physical quantity and converts it into a signal to be read and interpreted., Items such as switches that control the supply of electricity. and A device used to output data or information from a computer, eg a monitor, printer or speakers. that can be used together or separately depending on what function the product needs to achieve. These components are split into the three categories:
- inputs
- processes
- outputs
Some examples include:
Input
| Sensor | Function | Use |
| Light-dependent resistor (LDR) | The resistance changes as the light level changes, and the change in resistance can be used as an input | Solar garden lights and street lighting |
| Thermistor | The resistance changes as the temperature changes, and the change in resistance can be used as an input | Fridges, central heating systems and freezers to maintain temperatures |
| Piezoelectric sensor | Can change mechanical motion or force into electrical energy - it can produce an electrical pulse from pressure, such as by hitting it | Igniting lighters and in microphones (where soundwaves create pressure that makes the electrical pulse) |
| Sensor | Light-dependent resistor (LDR) |
|---|---|
| Function | The resistance changes as the light level changes, and the change in resistance can be used as an input |
| Use | Solar garden lights and street lighting |
| Sensor | Thermistor |
|---|---|
| Function | The resistance changes as the temperature changes, and the change in resistance can be used as an input |
| Use | Fridges, central heating systems and freezers to maintain temperatures |
| Sensor | Piezoelectric sensor |
|---|---|
| Function | Can change mechanical motion or force into electrical energy - it can produce an electrical pulse from pressure, such as by hitting it |
| Use | Igniting lighters and in microphones (where soundwaves create pressure that makes the electrical pulse) |
Process
| Control device | Function | Used |
| Switch | A switch can either allow or prevent electrical power from flowing round a circuit | Any device that needs power to be turned on and off |
| Resistor | To limit the flow of current - they are made to restrict current flow in varying degrees (resistance) | All electrical products - it helps control the flow of current and protects delicate components from being overloaded |
| Programmable components | A programmable component is a chip that can be programmed to make decisions based on an input | Most modern electrical products - washing machines are programmed to work when the drum door is shut and the on/off button is pressed |
| Control device | Switch |
|---|---|
| Function | A switch can either allow or prevent electrical power from flowing round a circuit |
| Used | Any device that needs power to be turned on and off |
| Control device | Resistor |
|---|---|
| Function | To limit the flow of current - they are made to restrict current flow in varying degrees (resistance) |
| Used | All electrical products - it helps control the flow of current and protects delicate components from being overloaded |
| Control device | Programmable components |
|---|---|
| Function | A programmable component is a chip that can be programmed to make decisions based on an input |
| Used | Most modern electrical products - washing machines are programmed to work when the drum door is shut and the on/off button is pressed |
Output
| Output device | Function | Use |
| Speaker | Uses pulses of electricity to move an electromagnet that vibrates to create sound | Headphones and radios |
| Motor | Converts electrical energy to kinetic energy that can turn a spindle linked to gears or wheels to make them move | Cars, trains, blenders and fans |
| Light-emitting diode (LED) | A long-lasting, low-power light | Torches, lamps and power indicators |
| Output device | Speaker |
|---|---|
| Function | Uses pulses of electricity to move an electromagnet that vibrates to create sound |
| Use | Headphones and radios |
| Output device | Motor |
|---|---|
| Function | Converts electrical energy to kinetic energy that can turn a spindle linked to gears or wheels to make them move |
| Use | Cars, trains, blenders and fans |
| Output device | Light-emitting diode (LED) |
|---|---|
| Function | A long-lasting, low-power light |
| Use | Torches, lamps and power indicators |