EEVblog 1573 - TEARDOWN: How a Rotary (Angle) Pulse Encoder Works

11:39 94€ per unit 🤨 It must be shipped in some really beautiful handmade wooden box decorated by japanese masters with a golden painture mixed with the tears of a unicorn

At 12:29 rotate by about 75 degrees anticlockwise the part you are holding so that the remains of the plastic rivets line up in top and bottom halves. It is then obvious that you have the the spring is in the wrong location. Possibly the other long piece of metal then goes between that spring and the shell wall.

I have been using this kind of encoder (manufactured by Alps) in flight simulator hardware. It is used for selecting heading, speed, altitude, radio frequencies, etc. Extremely reliable, not a hiccup in 20+ years of everyday use.

Long spring goes opposite to the indented one, you can see the place for it. The reason it stopped working after contact cleaner is you removed the lubricant that provides drag between the shaft and the bump mechanism, so it would not move the switch. Probably would have worked with a drop of silicone oil down the shaft, to make a thin viscous film. The reason it failed was probably the low viscosity oil evaporating out of the switch.

im so glad you actually made a video for the teardown. very educational. thanks a lot

Long sprint pushes the white part against the cogwheel, the other shaped spring pushes against the cogwheel from the other side so the clickety ratchet action is balanced and smooth and probably to ensure a full step is made and the whilte part stops centered.

Many years ago, I wanted to convert an up-and-down buttons for a synthesizer to a shaft encoder. I wasn’t smart enough to design it so I put it in front of two other engineers. One used a PIC micro controller, and the other use some 74 LS something logic and both gentlemen able to do it. The same thing as your pulse encoder does in one little package. Very advantageous. I went with the logic and not the PIC…

If your reading glasses are marked 1.25, that's the diopter value, which is the reciprocal of the focal length in meters.

I was trying to figure out how it would work and was expecting some kind of directional clutch but the actual mechanism is elegantly simple. I too wonder why it is not more popular.

The quadrature encoders are trivially easy to decode in hardware - you only need a D flip-flop and you will get out a clock and direction. One of the encoder outputs is connected to the clock of the D FF, the other output is connected to the D input on the flip-flop. Now if you turn the rotary encoder, the Q output of the D FF will give you the direction, and the clock used to clock the flip-flop is a clock for pulse counting. It's not an efficient way as you cut your encoder pulse count down, but it's a cheap and easy way to get direction and clock decoding.

The spring was FLAPPING IN THE BREEZE dave

I saw some like that in the USSR stuff before. Every one I saw was broken for what it's worth.

Awesome video, i love when you explore rare components

Nowadays obviously this would be done in software but the mechanical solutions always make me smile.

The problem with the design is that it is way too german to survive average users and our price competitive manufacturing. It just does not forgive any mistakes! It must be manufactured precisely to very tight specifications and it must be used in near perfect conditions or otherwise it just will not work. The approach is just not fit for the modern era of disposable everything.

First time I've come across a mechanical encoder. Definitely worth the teardown!

Just looked up Rotary angle pulse encoder, and the Wikipedia page uses a screenshot from this video 😂

Very interesting component!

Add velocity to your encoder interface so we don't have to turn the thing 100 times to change a value from 0 to 10...

What an outside the box way to think about how rotary encoders work! Performs the same task in a really cool way.