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By Julian Dodman

Wireless Charging, Great….. Right?!

Or is it just a marketers fantasy…?

Modern technology is brilliant! We have Gb/s optical cables, full duplex data transmission, Quantum Dot LED displays, the list goes on. 

But there’s one marvel that really ruffles my feathers… wireless charging in mobile phones. It’s made out to be this amazing cable-free way for you to charge your phone, but is it really that great? Let’s find out!

Okay, first let me explain a little bit about how wireless power transmission works. As you may already know, electricity is the flow of electrons through a conductor (or rather, the electrons bumping into each other like a Newton’s cradle). 

Electrical flow or current (remember this for later) is called an Ampere which you might be familiar with! 

So, now you know about electrical current, let’s start talking about electromagnetism. When current flows through a conductor, the charged particles create magnetic fields around that conductor. The strength of this magnetic field is proportional to the current flow, so larger current = stronger field.

The electrical field created by a single line of wire is almost imperceivable, which is why inductors exist (an inductor is just a coil of wire). When current flows through an inductor, the magnetic fields converge and ultimately result in a larger field. 

Fields created from an inductor can interfere with other circuits and wires nearby, for example, when current flows through a wire, the fields induce current in the wire right next to it. (Incidentally, this is how transformers work!)

These fields inducing current in nearby conductors is how wireless power transmission works, there’s just one problem, direct current (DC) magnetic fields are incredibly weak which means you’d need to pass hundreds of Amps through your inductor to power anything…. 

This is where alternating current (AC) comes in. I won’t bore you with all of the maths and theory of AC, instead, all you need to know is that it travels back and forth through the conductor at a given frequency (Which is 50-60 Hertz in most countries). 

So what happens if we pass this AC though our inductor? Because it’s essentially traveling through the inductor nearly 50 times a second, we get an exponentially stronger field!

Right, now we’re talking! With our AC inductor, we can place another inductor somewhere near it and power stuff, excellent!

There’s just a teeny tiny problem… if we plug any AC signal into our phone it will instantly become a firework.

So, the way wireless phone chargers do it, is they use a transformer to step the mains AC down to a lower voltage (somewhere around 5-10V), use that lower voltage to power our first inductor. This means that our second inductor (the one in the phone), will have 5-10V AC induced into it. 

Then they use a rectifier to convert the nasty AC into 5V DC which is safe for the phone, and won’t bring about New Years celebrations early!

Well… now you know how wireless power transmission works, why don’t I like it? 

The answer is power loss… power loss is a problem that engineers have to work around every day. Electrical circuits aren’t perfect, and some power is lost, either in heat or electrical fields. 

Most circuits in your house/boat will probably have an efficiency of around 80%, which is pretty good in today’s standards. This means that about 20% of the power going into the circuit is lost in heat or electrical fields.

Before I go any further, I want to mention a little someone called Nikola Tesla… I think you might have heard of him. He’s only responsible for most of the tech we use today! 

You’ve probably heard of the Tesla Tower or Wardenclyffe Tower, Nikola Tesla wanted to use this tower to transmit power wirelessly across the world (using resonant frequencies and electromagnetism)! 

Sound familiar? This is the exact same process that our two inductors are doing! 

So why are we not powering anything wirelessly, can anyone tell me…? 

Yes, you at the back there! Correct, power loss. This process has a lot of power loss, most of it is lost in the environment (through capacitances to ground and such). This means that you can only really power anything meaningful a few tens of metres from the tower. 

So back to our wireless phone charger. Because of power loss, you have to charge it a few centimetres from the transmitter… surely that defeats the point of it being wireless?! 

You have to set the phone down on the transmitter… why don’t you just plug it in instead!

Not only that, but there’s even more power losses (yep, more). Converting the AC to transmit it, and converting down to DC to the phone, this process wastes power as well. 

So overall, wireless phone charging is around 30% less efficient than plugging your phone in directly (especially with the new USB-C Power Delivery (that’s a topic for another piece!)), and you don’t gain any maneuverability out of it!

My conclusion is that some marketer somewhere has gone, you know what would be cool, wireless charging. Hey, engineers, make our phones wirelessly charge!. 

Save your electricity bill / boat batteries… don’t support wireless charging.

Many thanks to Julian Dodman

I’m feeling a bit maudlin at the moment.

We’ve just travelled home in the car, listening to music. I like music. I used to be a rock chic, Marillion, Iron Maiden and Dire Straits. Then I started dancing and I started listening to music differently. I like music that makes me feel. When I dance I try to express that – the way the music is making me feel alters the way I move. Nowadays I find music that doesn’t make me feel something is a bit dull. I still love dancing to the Macarena and the Timewarp, but I wouldn’t choose to listen to them. I prefer songs like Lewis Capaldi’s Someone You Loved. He’s in pain and when he sings I feel that pain.

That’s what music is for.

But I haven’t been able to dance for 6 months. It’s a very close contact sport – not very COVID-19 friendly. A little bit of dance is starting back, but it is not the same. I am very grateful to the venues that are doing it, but it makes me realise what I am missing.

There is less dancing – fewer venues, limited numbers and shorter sessions. There’s no chance to dance with someone other than your partner. No dancing with the lights down, no losing yourself in the music. And only a small number of venues are open. Some are shut with no chance of opening. Hopefully one day they can, but that day is a long way away in a world that I can’t imagine. But one of the most painful things is the people who still can’t dance. We are only allowed to dance within our own family group or support bubble. That means the people who don’t live with a dancer can’t dance. That’s a very high proportion of the dancers. It makes me feel awful, knowing that they can’t do what they love and I can. All in all, I love dancing but hate the way the world is affecting it.

Thinking about dancing makes me hurt. Listening to music that makes me feel – music that I would love to dance to because it makes me feel – hurts too much. It just makes me sad. Everything about it is painful at the moment.

I’ve tried to replace dancing with other things, baking, walking, watching films, but music is always around and it takes me right back down. I will suddenly dissolve into tears at random times. The reason being that a song has come on that makes me feel something and I can’t cope with it.

But I feel silly for feeling so sad. Our incomes were affected a bit, but not a lot. None of us has been ill and no one we know has been. We are privileged.

I suspect I’m not the only one who feels like this. We have all had our lives changed. Some of the changes might actually be good in the longer term. We were consuming far more than was good, safe or necessary. Having less of a ‘buy it now because I can’ culture is no bad thing. But change can be hard.

I look back to the biggest change I’ve ever had – having children. That was incredibly hard. It caused pain and turmoil but was so worthwhile. The other big change I’ve had was moving to the boat. You’ve read about the multitudes of disasters we’ve had, as well as the fun times.
Change can be difficult.
Having children and moving to the boat were my choice. No one told me to do it. Which meant it was exciting and positive as well as challenging and difficult.

This current change is prescribed. I can see it hurting people I care about. I didn’t choose it and I don’t have any control over it. It’s not surprising that I sometimes struggle.

I suspect a lot of other people are also finding it difficult. They might not miss dancing (or quietly weep as they wish the supermarket would stop playing emotional songs) but I’m sure most of us have something we miss, even if we also have things we like.

Change is hard and that’s okay.

I’m worried about the world going back to ‘normal’. If dancing goes back to the way it was I’m going to keep crying on my dance partner! Tears on a dance floor will make it slippery!

I think it might be healthy to accept that this might be hard at times and be open and honest about what we find tough.

Start here, drop something in the comments. What do you find difficult?

It’s bitterly cold outside and fairly wet, so I’m going to reminisce about the summer. When we had the sun and could feel its warmth.

Those of us on the BBB spent most of the summer travelling. We made it into a different county, and virtually to the sea!

We saw the Earith seals, travelled through the tiniest windiest rivers, the largest deepest rivers and visit many lovely pubs. But the story I want to tell you about happened on our way back.

We were planning on stopping at a mooring by a nice pub that we’d used many times. We were cautious – we know the mooring is against a cow field that you have to cross to get to the pub, although the cows are generally used to boaters and not a problem. But it’s still wise to be cautious.

As we came in to moor, another boat called us over. They weren’t exactly moored – they were tying the boat up, but quite wonkily.

It was hard to put my finger on what – but something wasn’t right.

The man from the other boat called us over and asked for some help. It turned out that a sheep had ended up in the river and they wanted to help it out.
That made more sense. they weren’t mooring – they were stopping for a moment to help the sheep.

But the sheep didn’t want to be helped!

Sheep are quite big. Bigger than I imagined. Bigger than most dogs. And sheep in the water get waterlogged, which makes them heavy (and wet – think wet dog smell combined with farmyard). But that wasn’t the biggest problem. The sheep wanted help. But it didn’t want us to get near it. Whenever the three of us got nearer than about a metre, it went further into the river.

We did what us humans do in these situations. We stood around and debated the situation. While we debated, the lady who was on the other boat came over. She walked straight towards the sheep and put her hand out as if it were a dog or a cat.

The sheep didn’t appreciate this. It didn’t go and sniff her hand. It freaked and leapt sideways – straight out of the river!

Great – the sheep is out and safe! We can moor up properly, the other boat can continue on their way.

But…as the more astute amongst you will have noticed – the mooring was against a cow field. Not a sheep field. The other boaters were convinced that there was a bull in the field. I could see heifers and big calves. They don’t put bulls in with calves. But I don’t like being in fields with heifers and calves.

The freaked sheep leapt out of the river and straight into the cows in the field. The cows were now freaked, too. The cows started chasing the sheep around the field – cue Benny Hill music!

Cows are very, very big. And they aren’t very nimble. If the sheep stopped or slowed down (which is likely because it had been swimming for ages) the cows will trample it.
They often put a sign with a phone number for the farmer on the fence to the field. But that was on the opposite side of the field to where we were. For some reason they never put those sign near the river.

Brave (or insane) Mr BBB to the rescue!

He decided to cross the field to find the farmer’s number. The sheep and cows were at the furthest part of the field from him and the cows were totally focussed on the sheep.

Until he got three-quarters of the way across the field. Then the spooked cows spotted him. They chased him across the field! Thankfully, he was faster and escaped.

But… he was on the other side of the field to me and the boat.

The sheep (I had named Flossy and decided it was female) had used the distraction to hide in some long grass and trees. So the cows had no aim – they were wandering around looking unhappy and stressed. In front of the boat.

As they passed the windows it became clear that one of them was definitely a bull. With plenty of the things that make bulls…bulls. Quite a lucky chap, in that regard!

So, to recap. The second boat has gone. Ade is outside the field. I am on the boat eyeballing some stressed cows, knowing there is a rogue sheep around.

Mr BBB found the number, which was only for evenings. It was early afternoon. Unsurprisingly, no one answered.

It still wasn’t safe for either of us to cross the field.

So Mr BBB went to the pub while we considered what our options were!

The best idea we could come up with was me moving the boat to the uneven haphazard mooring outside the pub – not in the field. But I would have to get off the boat to remove the mooring pins. Or leave them behind and risk not being able to moor.

I wasn’t happy about the plan, but there wasn’t much choice. Between us, we’d called the council, police, RSPCA and Environment Agency and none of them could help.

As I was waiting for the cows to move far enough away that I could remove the mooring pins, I could see a boat coming towards me.

It had a lot of people, music and lovely looking drinks. And, on further inspection…Mr BBB! As the boat passed, he hopped off and onto our boat!

We waited a bit longer, for the cows to settle, then between us, we unpinned and moved the boat.

We had a well deserved evening at the pub, and tried calling the farmer every half an hour, or so, with no result.

That night we went to sleep to the sound of poor old fluffy bleating on the edge of the cow field. The other sheep had given up calling and gone to sleep.

The next day we had to go, so I don’t know whether Flossy was reunited with her friends or made her peace with the cows. I like to imagine that she made friends with the cows and all were happy. 🙂

Here’s my latest Medium.com writing. It’s quite boaty!

https://medium.com/publishous/a-restroom-revolution-9313adf2c7d9?source=friends_link&sk=e4a477f176777e06a9f1de7a8e6aa7de

Enjoy (and don’t forget to clap)!