We use photocells a lot in lighting control, and I’ve harped on extensively on this site about how good they are. Then, a random conversation with someone regarding robots led me to start thinking about what other things photocells can be used for.
If you don’t know, photocells are devices that convert light energy into electrical energy. They are commonly used to control outside lights but the impressive technology is also found in a few other surprising areas.
This article is as much for my benefit as readers because I was curious to find out what photocells are used for, so hopefully you also enjoy it!
Photocells, also known as photoelectric cells, are electronic devices that convert light energy into electrical energy. They are used in various applications, such as street lighting control but here are some surprising ways that photocells are used in everyday life.
Blood Oxygen Monitors
One of the most common uses of photocells in healthcare is in blood oxygen monitors. As the name suggests, these devices use a photocell to measure the amount of oxygen in a patient’s blood.
My basic understanding (remember I’m an electrician – not a doctor!) is that the photocell emits light which passes through the patient’s skin and is absorbed by the blood.
The amount of light that is absorbed is proportional to the amount of oxygen in the blood. The photocell is used to measure the amount of light that passes through the blood and the device calculates the oxygen saturation level. – Pretty impressive stuff in my book.
Being able to monitor the amount of light in an area has great environmental impacts and helps people working in all areas of environmental work automate some processes.
For example, photocells can be used to determine the amount of sunlight that is reaching a plant or to monitor the amount of light pollution in a city.
This is a great example of humans using photocells to easily collect data, which can then be analysed and actioned by real people, or control entire automated processes.
If we are trying to limit human interaction in the plant-growing process, photocells can be used in irrigation systems to monitor and control water usage.
By detecting the amount of sunlight and adjusting the amount of water that is delivered to plants accordingly, not only does it save water but it ensures that plants receive the optimal amount of water for growth and development.
Amazon has some pretty impressive ones if this sounds like your cup of tea.
Some people like me with a small garden would be sad to see a basic function such as watering plants taken away, but when on a much bigger scale, automation removes the risk of costly human error.
I wouldn’t say I was a car person, but when given a new work van, the fact that the lights automatically turned on when it got dark was a nice feature.
I appreciate this goes firmly in the bucket of first-world problems, but most drivers have felt the frustration at seeing a vehicle on the road at night that has forgotten to turn its headlights on.
Thankfully photocells are now common in the automotive industry and do away with this problem. As well as turning the lights on and off, they also detect the amount of ambient light and adjust the brightness of the headlights accordingly.
As well as being convenient, all this automation helps to improve visibility while driving at night and reduce glare for oncoming drivers.
In my experience, some solar-powered devices are junk and shouldn’t have had the energy wasted creating them – I’m looking at you cheap, tacky solar lights in the neighbour’s garden!
However, there are lots of uses of solar power that are far more convenient and have become the norm, such as calculators and children’s toys.
The photocell detects when there is light and converts it into electrical energy, which is stored in a battery. This energy is then used to power the device when there is no light.
Photocells are used in a variety of industrial applications, such as in the manufacturing of semiconductors and other electronic components.
They are especially useful because they can detect the presence of materials or measure the thickness of a material. This has a great benefit in improving consistency in the factory and monitoring overall quality control.
The industry loves to automate processes and take the human element out of the system, whether you think this is good or bad for mankind, photocells are a vital part of this process.