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Bike music


The topic of portable audio on a bike often becomes relevant after regular pokatushek. In itself, riding a bike with a group of alkobiker familiar faces is not like ordinary meetings. Most of the way, everyone is in silence. From the monotonous torsion of the pedals and the relatively poor nightly variety in front of the eyes (during the day we work and we ride in the evening) something called desire turns into boredom. Bored for a long time monotonously silently pedal, lonely. Which exit?
“Everyone sees only what is already in it” - does not consider this article as a guide to stealing the silence of a neighbor. No one did, and is not going to.
Need a connecting element - music. You listen to it - you know what a neighbor is listening to. Instead of speaking, we get the opportunity to listen. Do you often have moments in life when all people listen and are silent? (minibuses with radio do not count, there the driver gives his ears to the radio station, apparently from the fear of not knowing what to do with them). Therefore, it is very important to listen to what you really see fit and thoughtful. Something I'm not talking about that.

I met commercial systems in the form of flasks (1), boxes on the steering wheel (2), and a promo project of some designer (I don’t remember my name, but I actually invented it before) in the form of a backpack with columns (3), trailers ( four). All of them are quite expensive and low-powered (except for trailers naturally).


I assembled the first simple amplifier on a microcircuit according to a scheme from Radio magazine about 5 years ago.
I didn’t have any concepts about efficiency, types of amplifiers, output power, input overload. I knew that 12V at the entrance should give "loud enough."

Task


And so, to create a portable music rom, we have to decide, in a rustic way, what we want to have at the exit:
')
Loud, light, with high efficiency (so that there is enough for the night) the system connected to the pocket player (telephone).

In Russian:

1) Player / Phone
2) Amplifier
3) Speaker
4) Power supply

1) Player


Go any! which has a headphone output.

I am using a Zune 4GB player. I would like to have a player with a higher output signal, I feel I can not squeeze all the juice out of the amplifier. From experience I will say that it is not convenient to hold the player in your hand on a bike with a cord. A bundle of player-amplifier jack-RCA over the shoulder I wanted to replace the system with bluetooth, but it requires additional attention with power.

2) Amplifier


The following types of audio amplifiers exist: A, B, A / B, C, D, G, H, T ...
Read about them you can elementary, that's what is important to know:

Amplifier Class "A" is considered the highest quality. Efficiency is usually 20%, yes, yes, this is a heater. Without a radiator, chips are usually cut down immediately. The transistor operates in open mode: it amplifies both the negative and positive half-wave signals. At the same time he eats in idle as much as at the maximum.
It does not suit us.
Amplifier Class "B"
Its advantages are relatively high efficiency (50-60%). One transistor amplifies the negative, the other - the positive side of the half wave. Significant sound distortions appear at the moment when the signal passes through zero.
It does not suit us.
Amplifier Class "AB"
Naturally, electronics are cubes, we take and connect the two classes listed above, take each one according to its advantages. Amplifiers of this class are the most common.
Already better.
Amplifier Class "D" (close class "T")
This is the last class about which I will tell. The rest are too rare and they are not necessary.
The basis here is PWM modulation. Due to the fact that transistors operate in a pulsed mode, the efficiency tends to a very good figure from 80% to 98%! Accordingly, there is no need to remove heat, the dimensions of the amplifier are significantly reduced. With sound, too, everything is in order.
This is exactly what we need.

Walked through the catalogs of audio amplifiers chips. Found a wonderful TA2024.
But due to the relative complexity of searching for capacitances, inductances, and manufacturing a circuit board, I decided to buy this miracle from the Chinese. As I was glad - they also read Habr these catalogs and were unanimous in choosing the heart of the amplifier.



The motherboard manufacturer's shop is Sure Electonics . Quality 5 points. Price $ 17! They sent all the screws, clips and wires. The quality of the latter is really terrible. There are several overlapping connectors on the board. You want to clamp the wires, you want through the tulip.

Specifications:

Why connect it?



3) Loudspeaker


I admit honestly, I don’t like to read how many ohms winding from a column on my ancient music center (1 speaker 3 ohms, another 8 ohms). I didn’t want to look for another loudspeaker - I don’t know where to find another light and small one. You will feel very well what a sound corridor is and the most amazing sound will certainly be in the tunnels and under the bridges.

4) Power

Since I'm lazy, I use a 12V 4.5 A / H lead battery (which is in UPS, although more often there is 7 A / H there). Two Li-Po of 11.1 V. lie. 2.5A / H. Weigh 300 grams but it is not for us.


How good is the battery?
I do not remember the volume levels before the trip and after (4-6 hours drive). It's hard to compare. The sound gets a little quieter. But at night enough with his head.

Experience of use


  1. Health
    Nevertheless, I do not recommend carrying the amplifier on myself for a long time. This option is the easiest, but quite exhausting. After 50 km, any little discomfort before will turn into a callus after. In the backpack between the back and the column, I usually put a sheet of trapeak in shape (tourist track, foam) for greater comfort. It rests on the battery. I love a dry back, I do not like backpacks, but I can't refuse alko bikers to my friends. Have to sweat.
  2. Usability
    All this good described above is placed in a backpack empirically. The backpack is needed with a thin back wall so that the sound is not extinguished. (I usually open my pocket)
    The usability of this system depends on the flexibility of the player’s cord and the place where the player can fit and reach without any problems. (some pocket) Ideally, of course, mount it on the steering wheel and discard the wire. Broadcast via bluetooth to the amplifier.
    The exact weight of the system can not say, in the region of 3kg.
  3. Environment
    There is such a pollution factor - noise. Honestly, I can't understand why there are “chrome” exhaust pipes with increased “volume” on sale. The car has a guest on the level of noise, it should not pass inspection with a new "improved" exhaust pipe. This is more important than the glass behind which people hide their affairs. We have so much noise that you need to respect the streets you ride. Even the forest, when you get into it, it seems that here it will avenge you for loud music.
    In the forest, I am kidding and put singing tropical birds, people's eyes roll out on their foreheads, where do birds come from?)
  4. Electronics
    Players fall out of the hands. Simple cheap cords between the player and the amplifier in the backpack are bent, after a month of other trips from vibrations there is a probability of breaking the wire in any travel place.
    It is better to take a spare wire jack-rca.
  5. Society
    Listen to people quietly, usually not everyone shares the creativity of the studio “night whim” and A.Razembaum's album “On the love plantations”.) No matter how much you bother with it, it is impossible to love them forcibly.
    The only step - tell about him at the fire, if you want to share what he touched you so much, do not be silent).
    I had an idea to put audiobooks ... but it is on extremely long trips, when you can be silent for hours.

Conclusion and ideas



Unfortunately, I did not find a normal video from pokatushki, where you can listen to the volume of the system. The goal was not to wake someone up at night or to disturb someone. Stereo amplifier, one speaker - hence the sound is mono. My next find was in the transmission of the second channel by radio to the second bike with an amplifier! The second person does not have a player, only a radio. It takes the left channel from my player, and I drive the right one. As a result, we have a full stereo. Moreover, since we have a transmitter for a second bike, why not take this signal to everyone else, but not to the amplifier, but to light-music?

Imagine a spectacle: a gang of cyclists with music rides, and the rest of the time beats the light. If we were many, if it were worth it, I would do it. And on that note, I say goodbye.

Ps.
Found amplifier on dealextreme on this microcircuit

Source: https://habr.com/ru/post/133035/

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