At noon and lunch time, Yuwen Wen, who was reading memorials in the study, was too lazy to move his seat and asked the palace maids to bring the meal in. Zhang Lihua, who was on the rotation as a "secretary" this month, packed up the desk and accompanied Yuwen Wen to have a meal together.

It was early winter and the weather was cold, but the room was on "heating", so it was as warm as spring. Yuwen Wen saw that the plate brought by the palace maid had lychee flesh. Although there was a plate in front of Zhang Lihua, he still signaled the palace maid to put his part in front of Zhang Lihua.

"It's not easy to transport lychees from afar, try them."

Zhang Lihua saw the crystal clear lychee pulp on the plate, and said with some emotion: "This canned fruit is really magical. The lychees from Lingnan have been transported to the capital from thousands of miles away, and are still fresh and delicious."

"I always heard people say that lychees are delicious, but until now, I have enjoyed my food."

"Is it delicious? Then you can't eat too much. One meal and two dishes are enough. If you eat too much, you will get angry. Just eat some of it every day."

Yuwen Wen reminded him and looked at the food in front of him, his eyes lit up: "This dish is interesting to make the skin of lychee pulp, and I will try it as the filling of meat. Yes, it's chicken, it tastes good!"

Seeing this, Zhang Lihua asked, "This dish is called 'lychee chicken ball', does Erlang like it?"

"It's not bad, the palace chef has also started to make Lingnan cuisine?"

"It was the chef of Wuweizhai Fanyu's semi-colon who came to Beijing, so this dish is included in the recipe."

Yu Wenwen, who was very sensitive to dietary costs (stingy), asked after hearing this: "Why did you go to Beijing? What are you doing when you go to Beijing from afar? You are mobilizing a lot of people."

"This is not lychees. Canned Longyan food is being supplied to the capital. Wuweizhai from Chang'an invited the chef from Fanyu's semi-colon to come over to teach everyone how to use lychees and longan to cook. The chef will cook for the palace by the way."

Wuweizhai is a royal property. Yuwen Wen nodded after hearing this: "This is almost the same."

He has no particular concern for diet, but he has never liked to waste it, and he does not want to be cheated by others as a sucker.

Anyone who dares to make a chicken tongue dish (using chicken tongue as a dish, spends hundreds of chickens at a time) or makes a "special egg" that always costs one, he will give him a free boat ticket to Australia to open up the land.

Throughout the dynasties, "internal affairs" (interior affairs) have been the most common areas, among which "procurement" is particularly serious. As long as the supervision of the food is not strict, there will be a great operating space to fill your personal pockets.

Using inferior products as good products, or colluding with internal and external fraud to falsely report the selling price are common methods of "taking advantage" and there are countless other methods.

Yuwen Wen is not short of money, but it does not mean that he is willing to be a sucker and be taken advantage of. Even if his family is treacherous and wants to eat good food, it is not bad to spend money, but if you spend money, you have to really eat good things.

The ingredients are paid for, and the seasonings are the same. Even if the seasoning is salt, if the price of "fine salt" is spent when purchasing, the salt must be white and fine salt without impurities.

Anyone who dares to play tricks on food and plays "added value" to fool him will be furious.

Therefore, Yuwen Wen thought there was no need to travel all the way to Beijing for a dish, but they came to Beijing to "on a business trip" and went to the palace to "take the turn", which was different.

The food today was good, Yuwen Wen was very happy to eat. Zhang Lihua couldn't help but breathe a sigh of relief when she saw him happy.

Yuwen Wen's style, which is obviously rich but very stingy (in terms of diet), is a bit troublesome to serve. If she always arranges ordinary meals, the queen will be dissatisfied, but if the food arranged is too "luxury", Yuwen Wen will chat.

After dinner, Yuwen Wen looked at the clock. It was lunch break and there was a beautiful woman by his side, so he had to do something interesting.

A music cabinet with four "universal wheels" and shaped like a small cabinet was pushed to the desk by Zhang Lihua. Yuwen Wen watched Zhang Lihua operate this new product with interesting interest, and watched her "feed" the punched paper tape (music score) into the "inlet".

Then start the clockwork.

The pleasant music sound came from the trumpet above the music cabinet. Zhang Lihua looked at Yuwen Wen and saw him nodding, so she raised her hand to twist the knob below the trumpet.

The knob that can be rotated left and right is twisted slowly by Zhang Lihua, and the music from the trumpet's mouth gradually becomes louder.

From the tinkling springs at the beginning, to the gurgling waters, to the rushing rivers, and finally, the roar of the Yellow River waterfall.

Yuwen Wen felt the music deafeningly. Seeing Zhang Lihua covering her ears, he quickly signaled the other party to lower the volume.

Seeing that the sound of the music cabinet could change at will, Yu Wenwen was very happy. He left his seat, walked to the music cabinet, rubbed the latest experimental product, and looked happy: "The noise has finally disappeared, it's really not easy."

Zhang Lihua smiled and said, "Of course, it's not easy. If it weren't for the 'filter' invented by Mr. Yuan, this electric speaker wouldn't be useful at all."

"The electric speaker is an informal name, its scientific name is a speaker."

After Yu Wenwen finished speaking, he took off the side panel of the music cabinet, looked at the complex internal structure and the huge battery, and felt a lot of emotion.

A speaker (electric speaker) is an electroacoustic conversion device that can transmit the fluctuations of current to the diaphragm, thereby emitting sound, realizing the transformation from electrical energy to acoustic energy.

The principle of a speaker sounds very simple, but he doesn't understand how to implement it.

Only knowing that the combination of microphone (picture) and earpiece (speaker) is the phone.

So, technicians began to study and explore the principles of pickups and speakers, and this exploration lasted for more than 20 years.

A pickup (a device that converts sound vibration into current) has not been "invented" for a long time, but the speaker was born.

At the end of a paper big speaker, connect a circular magnet to make the end of the big speaker located at the center of the ring magnet, and then wrap a wire at the end as a voice coil.

When the voice coil is energized and a current flows through it, an electromagnetic field will be generated, and it will form a magnetic balance with the magnet of the outer ring, which is manifested as the voice coil is relatively stationary at the center of the ring magnet.

If the voice coil current fluctuates, it will inevitably cause electromagnetic fluctuations, and the magnetic balance with the ring magnet will be broken and its position will move (continuously tremble).

This movement (shaking) will cause the paper horn to vibrate, and the paper horn will make a sound.

The principle is very simple, but it took more than twenty years to implement it.

However, although the speaker can pronounce with the change of current, the sound produced is very noisy and has no practical value at all.

In addition, the useful pickups have never been made, so the speakers that must be matched with the pickups have become useless.

However, if you change your thinking and let the speaker "start a business alone" and use it as a magnifying device for music box music, the useless ribs will become chicken legs.

The music box will emit music. The principle is that the tone combs representing different notes are tamped. So, what will happen if each tone comb is tamped to achieve the effect of "circuit"?

The current emitted by the circuit connected to each sound comb is different. When it is transmitted to the speaker, these currents can be restored to the corresponding sound by the speaker and released.

This idea is good, but the sound released is still noisy, so the speakers that "start a business alone" face the end of "bankruptcy".

The pickup is "difficult to childbirth", the speaker is "on the verge of bankruptcy", the dream of the phone is far away, and at this moment, a turning point appears.

That is the "filter" invented by the "former" fortune teller Yuan Tiangang, which gives the speaker the possibility of "starting a business success".

The filter filters out the miscellaneous current in the circuit, allowing the current emitted by the comb circuit to enter the speaker circuit and "produce sound". So the noise is gone (so small that can be ignored), and only pleasant music sounds come out of the speaker (tuning is required).

Although the pickup is still "difficult" and the phone still cannot be invented, the speaker has its place to work.

The new music cabinet can adjust the volume by rotating the knob. The volume can be deafening and easy to use. You just need to change the battery from time to time.

This is a new product suitable for wealthy people to show off their wealth. After the merchant sells the product, he can ensure long-term profit by providing after-sales service (changing the battery).

At that time, people who cannot afford to replace batteries (standardized products) are not qualified to show off.

The use of new technologies has given the product a high added value. Only by making money from rich people can you make a lot of money. Yuwen Wen was enjoying the music and thinking about the rolling copper coins, and he narrowed his eyes with joy.

Zhang Lihua sat beside him and asked softly: "Erlang, should you play in sequence, or do you want to play singles?"

Yuwen Wen opened his eyes and asked in surprise: "Is there such a function?"

"Well, the experimental machine has this function."
Chapter completed!