乾電池1本から100Vを作る

Summary

このビデオでは、1.5Vの乾電池から100Vの電圧を生み出すブーストコンバータの制作過程を紹介しています。有名なコッククロフト・ウォルトン回路の代わりに、シンプルなブーストコンバータを使用し、パワーMOSFET、ダイオード、コンデンサーを活用します。原理説明から実際のPCB製作、そして実験による検証まで、一連の流れが詳しく解説されています。また、乾電池の電圧を5Vに昇圧する村田製作所のモジュールの使用や、複数のブーストコンバータモジュールをカスケード接続して高電圧を得る工夫が紹介されています。最終的には、単一の乾電池で150Vを超える電圧を実現し、その危険性と電圧が負荷によってどのように変動するかについても触れられています。

Takeaways

• 😀 They will make a 100V dry cell battery using power electronics
• 👷‍♂️ They will use a boost converter circuit to step up the voltage
• 🔌 The circuit only needs a single 1.5V AA battery as input
• ⚡️ The battery voltage is stepped up using an inductor and capacitor
• 🤔 Driving the MOSFET switch is challenging with only 1.5V input
• 🙌 Found a Murata module to boost 1.5V to 5V for MOSFET control
• ⚙️ Connected multiple boost converter modules in series to multiply voltage
• 🔋 Made a 150V 'dry cell battery' from a single AA battery
• 📉 Voltage drops under load due to no feedback control
• 💡Possibility to boost voltage further with more batteries in parallel

Q & A

What is the goal of the project in the video?

The goal is to create a 100V dry cell battery using only a single 1.5V AA battery.

What circuit configuration is used to boost the voltage?

A boost converter circuit configuration consisting of an inductor, switch, diode and capacitor is used.

How does the boost converter work to increase the voltage?

It works by storing energy in the inductor when the switch is closed, and then transferring that energy to the capacitor when the switch is opened, boosting the voltage.

Why was the Murata power module used?

It was used to boost the 1.5V battery voltage to 5V to provide sufficient voltage to drive the MOSFET switches.

How was a 100V output achieved?

By connecting multiple boost converter modules together vertically in cascade to achieve a high voltage gain.

Why did the output voltage drop under load?

Because there was no feedback control, the boost converters moved into discontinuous mode, and the battery voltage sagged under the high load current.

What was the maximum output current capability?

Only about 1A could be drawn before the output voltage dropped significantly due to battery limitations.

What improvements could be made?

Add voltage feedback control, parallel more batteries, add more cascade stages, and optimize the circuits for higher load currents.

What was learned from this project?

That while voltage multiplier circuits can generate high voltages easily, getting them to work properly under load with feedback and control is more difficult.

What future applications are possible?

With improvements, this circuit technique could generate voltages up to 3kV for specialized applications.

Outlines

00:00

😀 はじめに、ブーストコンバーターの原理説明

ブーストコンバーターはインダクタとスイッチ、ダイオード、コンデンサーから成り、インダクタにエネルギーを蓄え、スイッチのON/OFFによってコンデンサーにエネルギーを移すことで電圧を上げる。基本回路の原理実証のため、試作回路を作成し、入力電圧を上げていくことで出力電圧も上がることを確認した。

05:00

😊 MOSFET駆動用に1.5Vを5Vに昇圧するモジュール

ブーストコンバーターのMOSFETを駆動するのに最低5Vが必要だが、単電池では1.5Vしかない。そこでマウス社のDC-DCコンバーターモジュールを利用し、単三電池の1.5Vを5Vに昇圧してMOSFETの駆動に利用する。

10:02

🤔 1個のブーストコンバーターモジュールだと100Vまで昇圧するのは難しい

1個のブーストコンバーターモジュールで1.5Vを100Vに大きく昇圧しようとすると、インダクターに非常に大きな電流が流れる必要があり、単三電池ではそこまでの大電流は流せない。モジュールを垂直接続してステージを重ねる「カスケード接続」したほうが容易。

15:05

😮 3段階のカスケード接続で1.5Vを150Vに昇圧

3段のブーストコンバーター・モジュールをカスケード接続し、1.5Vを最初に2倍、次に2倍、最後に5倍して150Vに大きく昇圧することに成功した。これを使って単三電池サイズの携帯できる「150V乾電池」を作成した。

Keywords

💡ブーストコンバータ

入力電圧を増幅して出力するDC-DCコンバータの一種。このビデオでは、1.5Vの単3電池から100Vを生成するのに使用されている。

💡垂直接続

複数のブーストコンバータを直列に接続し、各段で電圧を順次増幅していく技術。このビデオでは3段の垂直接続を使用して100Vを生成している。

💡ドライセル電池

液体の電解質を含まない乾電池。このビデオでは1.5Vの単3乾電池を電源として、ブーストコンバータと垂直接続により100Vの乾電池を作成している。

Highlights

Introduction to the concept of creating a 100V dry cell battery using power electronics technology.

Discussion on the challenge of boosting voltage from a single 1.5V dry cell battery and exploring circuit configurations.

Explanation of why the Cockcroft-Walton circuit, often used for DC high voltage creation, is not suitable for this project.

Introduction to using a boost converter as a simple and effective solution for increasing voltage.

Detailed explanation of how a boost converter works, including the roles of its components.

Discussion on the importance of transferring energy from the inductor to the capacitor for boosting voltage.

Practical demonstration of a boost converter increasing the voltage and the challenges faced with MOSFET operation.

Solution for driving MOSFETs with low voltage using a Murata Manufacturing Co. module to boost voltage for the control circuit.

Step-by-step assembly of the boost converter circuit, highlighting the use of components from DigiKey.

Demonstration of the assembled boost converter successfully increasing voltage in a controlled experiment.

Discussion on the limitations of boosting voltage to 100V with a single module due to current and resistance constraints.

Proposal of a cascading approach with multiple modules to achieve higher voltage outputs effectively.

Successful demonstration of cascaded modules boosting voltage significantly, with safety precautions emphasized.

Creation of a 150V dry cell battery casing using 3D printing to house the cascaded boost converter modules.

Final thoughts on the project's success, limitations, and the potential for scaling up the voltage further with additional modules.

Mention of DigiKey's support and the availability of educational content on vector analysis for electronic design.

Transcripts

This video is brought to you courtesy of DigiKey

Good afternoon.

Today we're going to take advantage of power electronics technology.

We're going to make a 100V dry cell battery.

This is a dry cell power supply that can produce 100V here

We use only one 1.5V dry cell battery here.

Actually from this one small battery

How much voltage can you get out of it?

I'm sure many of you are wondering.

So that's what we're going to try.

First of all, we try to figure out what kind of circuit configuration we want to use.

If you search for DC high voltage or something like that, you'll find a lot of stuff.

The first one is the Cockcroft-Walton circuit.

This is a very famous circuit

It is often used to make DC high voltage

But if you look closely, you can see that an AC power supply is required.

This is a circuit that converts AC voltage to DC voltage

But this time, we use DC dry cell batteries.

So, with this circuit, it seems to be a little difficult to boost the voltage.

Converting AC voltage to AC voltage

The circuit that converts AC voltage to DC voltage is

There are various

Further boosting the DC voltage

The circuit that converts a DC voltage to a DC voltage is

It looks quite difficult.

For example, a flyback converter like this

There are some circuits like this

It's a little bit difficult to make this transformer part.

So this time, number 1 straight forward

And I'd like to proceed in a simple way

We're going to use a boost converter here.

Very simple circuit configuration

Boost converter is an inductor switch

This time we use a power MOSFET

And it can be composed of a diode and a capacitor

It's a very simple circuit

I'll explain the principle of operation in a moment.

For clarity, the MOSFET here is

Rewrite it as a switch

What's the most important thing about this circuit?

The energy that's accumulated in the inductor here.

If you accumulate it in the capacitor

From inductor to capacitor

It's about transferring energy

Let's close this switch first.

Then here's what happens

Current flows through this inductance and battery loop

The energy stored in the inductor at this time is

1/2 LI².

This L is the inductance

And I is the current through the inductor

And next when the current is flowing in the inductor

This switch is opened

Then there will be no current flow to this switch, so

So current flows through this switch.

And that current is

It flows into this capacitor here

If there is a load

Of course it will flow like this with load

Let's turn off the load for a moment this time, because it's in the way

The energy stored in the inductor

It is transferred to the capacitor

At this point, the energy in the capacitor is 1/2 CV².

C is the capacitance of the capacitor

By the way, the voltage of an ultracapacitor is

The integral of the current through the capacitor

This current charges the capacitor

The switch was turned off

Turned on again

When current flows through the inductor

And if you turn this switch off

Now we're going to put the current through the capacitor again.

Repeat this operation to increase the voltage

The current flowing in the inductor boosts the capacitor to

Let's estimate how much the capacitor can be charged

For example, this circuit

1mH inductor and 100µF capacitor.

1A flows through this inductor

Then the energy stored in the inductor is

1/2・LI²

Calculation yields 0.5 mJ

The energy of this inductor is

Assume 100% of the energy is used to charge the capacitor

Capacitor energy is 1/2 CV².

Actual calculation shows that the voltage of the capacitor is 3.16V

As explained earlier

By turning the switch here on and off

The energy stored in the inductor

The energy is transferred to the capacitor

By the way, when the voltage is low, it means

The voltage of the capacitor can easily go up.

When the voltage of an ultracapacitor is high, it means

The voltage increase becomes a little more difficult

because the energy of the capacitor is

because it is proportional to the square of the voltage

For example, let's say the initial voltage of a capacitor is 100V

If the same energy is stored in a 100V capacitor as before

The voltage of the capacitor only rises to 100.05V

So the voltage is increased like this

By the way, you can watch the following video about boost converters.

I made it before.

If you watch that video as well

You'll learn more about boost converters, and you'll be able to see how to use them.

Please take a look.

There is a link in the summary section

We are going to make a boost converter

Whether the boost converter actually works

We'll go ahead and verify the principle first.

This is Ichiken's original PCB and

Combination of inductors, capacitors, power semiconductors, etc.

Making a boost converter

Electrolytic capacitor

Inductors

And power semiconductors.

This is a diode

This is a capacitor in the output section

Step-up converter for verification of principle is completed

We will run this one.

The front side looks like this

The reverse side looks like this

By the way, here is a breadboard type printed circuit board

Sold on Amazon

If you would like to use it

Please purchase from the link in the summary column.

Then we'll do a proof-of-principle test.

Here's how it's set up

There's a voltmeter.

The top is the input voltage

The bottom is the output voltage of the boost converter

Now let's add the voltage

First, we set the input voltage to 5V

This time, the voltage is set to be boosted by a factor of 2.

Since the output voltage is 9.5V

Roughly doubled

Let's increase the voltage further

Now

10V

That gives 19.7V

Looks about right

Here we increase the voltage further

It's on fire

Thus the boost converter is

It was found to be working without any problems

There's just one problem

What it is is the voltage to run the MOSFETs.

This is a MOSFET

To run a MOSFET

Between this GATE-SOURCE

You will need at least about 5V

But this time we can use it as a power supply.

Only one of these batteries can be used as a power source.

The voltage of the battery is 1.5V

between gate and source here

Not quite the minimum required voltage of 5V

So without these power supplies

So driving MOSFETs without these power supplies?

I'm thinking, "This is going to be difficult.

I'm in a bit of a pickle.

I was looking for parts on DigiKey.

What an amazing part I found!

This is a product of Murata Manufacturing Co.

This is a module that boosts the voltage of 1.5V of a dry cell battery to about 5V.

This time, I will use this for the control circuit of MOSFET.

This is the circuit we are going to make.

With the Murata power supply module that we just used

Boosts the battery's 1.5V voltage to 5V

This voltage is used to control the MOSFET

This is used for the control circuit part.

Now we use the MOSFET as a switch

It can now be turned on and off

Then you can use a boost converter to turn the voltage of this battery on and off

We can now boost the voltage.

Now we will actually build the circuit

As usual, the printed circuit board is made from scratch.

And the components that we use there are

purchased from our sponsor DigiKey.

This time, I used surface mount components for weak electric circuits.

And for the power circuit part

We use a lot of through-hole components

Assembled as soon as possible

There's a printed circuit board, and then we're going to put a stencil on top of it.

There is this stencil hole

We put solder paste on top of the stencil

And then you can use a credit card or something like that.

And then you rub it here.

Solder paste in the stencil holes.

It is an image of pushing it into the stencil

It's done.

This is the difference between before and after applying solder paste

Below is before applying solder paste

Above is after applying solder paste

The area where solder paste is applied

Surface mount components are placed

Now that all the components have been placed

Next, we will bake them on this reflow plate.

We're going to put it on this one.

Put the board on top of this

Now we will burn it.

Now it is heated

So the temperature is going up and up and up.

I'm going to leave it like this for a while.

The solder seems to have melted.

Let's take it out.

I was able to solder quite nicely

First, let's see if it works with just the control circuit.

Put a single AA battery in

Voltage is 1.5V

Now let's look at the control circuit voltage

Now there is no battery connected to the control circuit

When this jumper is connected

Power is supplied to the control circuit and

5V voltage is supplied

Next, let's look at the voltage between the gate and source of the MOSFET

Here we have NE555

Pulse wave is emitted from there to drive MOSFETs

When you turn on the power

Now it looks like this

The amplitude of the pulse wave here is 4.5V

To drive a MOSFET

I found that I needed about 5V

4.5V is enough to drive the device.

There is no problem with the voltage level.

This control part sets the boost ratio of the boost converter

There is a trimmer resistor here, but

Adjust this part

Like this

In this state, the pressure increase is not that high

Conversely, in this state

The boost ratio becomes high

That duty ratio.

The longer the duration of ON

The higher the output voltage of the boost converter

Now that we know something is going to work

We're going to solder the power circuit components as well.

Electrolytic capacitors of 450V/100μF are used

Diode, 650V withstand voltage

N-channel MOSFET, also 650V

Inductor 100μH

The circuit is completed as shown here

Let's try an actual experiment

When you put a battery in

First of all, here is the input voltage. Here is the battery voltage.

1.5V

And right side output voltage

It is lower than the input voltage

This is because the control circuit is not powered yet

It's just the voltage drop across the diode

Drop from input voltage

Now turn on the control circuit

The voltage is boosted

It is working properly

The variable resistor here can be used to change the boost ratio.

Like this

Higher or lower voltage

Pretty good

You can increase the voltage like this

I know it works fine and looks good, but...

So, if I try to make 100V from here

There is only one problem

What is that?

Just one module here

If we try to boost the voltage from 1.5V to 100V

A very large current must flow through the inductor

And with only one dry cell battery

The current cannot be that high.

It is possible, but...

It's not like the voltage is 1.5 or something.

It drops considerably to 0.7V or something like that

This is because there is an internal resistance in the battery

And also because of the high current

Inductor here

Worst case scenario, it burns up

Other than that, power semiconductors are

must withstand high currents

So, with one module

Boosting voltage from 1.5V to 100V is

I guess I better rethink this.

I've been trying to think of different ways to boost the pressure.

I thought that this is the best way to do it.

I came to a conclusion

This boost circuit as a single module

If we connect the beads like this

I think it would be easy to create a high voltage

This kind of connection is called a vertical connection

Cascade connection.

For example, if you had a circuit that doubled the voltage in one module

where the voltage is doubled

Double here, too

And here also doubled

Connecting three of them gives a total multiplier of x8

So, for example, if you have a 1.5V input

This is calculated to be 12V.

Besides that, for example, here is 5 times

Here is also 5 times

And if we multiply the last step by 5

That's 5 to the power of 3, so we get 125 times the voltage.

Then it is 125 times 1.5V, so

That gives 187V

So to make a vertical connection

We will make several of these modules

Three modules are created and connected vertically

Boosting the voltage at the first stage

Boost the pressure in the second stage as well

And the third stage also boosts the pressure

We actually turn on the power supply

I think we're going to get a pretty high voltage, so

I'm going to put on insulated gloves as well.

Now we turn on the power.

There's a little beeping sound.

but it seems to be working fine.

I'm going to measure the voltage.

Here it comes!

156V

So the voltage of the dry cell here is 1.5V

100 times more than that.

The pressure has been boosted.

I made this kind of battery type case with a 3D printer

There are three modules inside.

If you put one AA battery for power supply here

Here's the positive pole metal

And the negative pole is

It is pasted here

There is an ON/OFF switch on the back side of the unit

Close the lid

It's something like this, pretty much like a battery.

This is quite interesting.

This is a huge 150V dry cell battery.

Just like a normal battery

If you always put out 150V

Very dangerous Dangerous Dangerous Itiken specification

So just to be safe

I put an ON/OFF switch here

But this one is also turned on

I don't have any LED indicators or anything on.

The switch ON/OFF is the only thing that determines whether the switch is ON or OFF.

It is a rather dangerous specification.

Let's measure the voltage of this giant dry cell battery again

The needle is inserted properly, but

Is it 144V?

The voltage is firm.

Let's do a little experiment

Normal dry cell battery, low voltage

Even if both ends of this terminal are short-circuited

No sparks will be generated.

But what happens with these 150-volt dry cells?

I'll try an experiment.

Here is a mechanical pencil lead

I'll try to short-circuit it.

It crackles pretty solidly

As expected from the high voltage

Voltage comes down a little bit

This is just one dry cell.

It's not as powerful as it should be.

I think the voltage drops a lot when you take a load.

I think it will drop to about 50V.

That's quite a jump, now.

Can you hear it crackling a lot?

Once it shorts out and discharges

Until the voltage rises like this

Since it seems to take quite a long time

Sparks don't fly easily when discharged continuously

If you give it a little time

There's a big spark, but

If you leave it only for a short time

Sparks will be such that they will hardly fly

This is because it takes time to charge the voltage booster circuit inside

By the way, what happens when you take the load off

I'll try it with this resistance

If you look at the voltmeter display

It is below 50V

With no load, 150V was being produced, but

When the load is taken like this

The voltage drops as soon as it reaches 50V

When a load is connected to the step-up circuit

The voltage is now lower

There are many reasons for this

There's about three reasons this time.

The first one is

is that we don't have voltage feedback.

If the circuit converts the voltage in this way

Usually there is a voltage divider resistor that monitors the voltage

This is how the voltage is input to the control circuit

The calculated pulse width is then input to the MOSFET

And so the feedback works nicely

The output voltage of the load is always constant

but this time there is no feedback control

This signal is input by fixed input

So the voltage of the load goes down.

The second one...

The current flowing through the inductor here is

Very important in a step-up circuit

It's called current continuous mode, and

There is a mode called current discontinuous mode

The boost ratio changes depending on the mode of operation.

In this case, the operating mode is not calculated.

So the mode changes depending on the load current

It means that the voltage will not be increased as expected.

And here's reason number three.

These dry cell batteries here

Actually, the current is always about 1A in the dry cell

This current of 1A is

This is a very large load for an AA battery.

If you put this much current into a battery

1.5V will drop to about 1V

The voltage at the input drops, which means

The output voltage drops as well

For this reason, we have changed to this 100V dry cell battery.

When I connected a load, the voltage dropped

So I'm going to summarize

Dry cell here

Voltage can be output up to about 150V

But if we just take the load

I found that the voltage drops accordingly.

We are using only one AA battery in this case.

If you connect some of these AA batteries in parallel

There is a possibility to boost the voltage a little more.

We're going to need a more robust battery that we're using for the power supply.

And if you increase the number of vertical connections in the module

If you go up to about 3kV

This circuit configuration seems to work.

But what I found out by doing it this time is that

The fact that the voltage multiplier circuit itself is somehow working is a good thing.

It's easy, but

If you try to make it work properly

It turns out to be quite difficult.

So here's today's sponsor, DigiKey

Here you go.

I hope you all know that DigiKey has a Japanese YouTube channel.

Do you know about DigiKey Japanese YouTube channel?

A new series is starting over there.

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Physical position, velocity, and acceleration

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This series is designed to help you use them in your designs.

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Please try this one!

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