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Help -What switch is this

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stuhagen

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I have spent a few years trying to find a rotary switch like this. Always thinking it was a rotary decoder but is not. It turns endlessly but only performs a 5-step fan speed level. If you look close there is a tiny ball in the one picture that has a solid copper ring. When turning, the ball goes around and then hits a stop but the knob can continue to rotate. Until it turns the other direction the ball then goes 320 degrees the other way and hits the stop again. The first picture drops onto the second picture piece.
I suspect, but could be wrong, as the it rotates it increases or decreases in resistance. But putting a meter on it, the resistance steps and isn't linear. I have 4 switches like this that no longer work and appear to have a short across the outer pins which makes contact simultaneously to both outer polls at the same time.


Alps%20Rotary%20%281%29%20%28Medium%29.JPG

Alps%20Rotary%20%284%29%20%28Medium%29.JPG

Alps%20Rotary%20%283%29%20%28Medium%29.JPG

Alps%20Rotary%20%282%29%20%28Medium%29.JPG



This is the circuit of how it works. It rotates and creates a momentary circuit closure to the fan speed stepper to increase fan speed clockwise and decreases speed counter-clockwise.

AC%20Circuit-2.jpg


I desperate to find a switch that can replicate this. Only other way to make a repair is to buy a whole used controller just to scavenge this switch.

Stu
 
I have spent a few years trying to find a rotary switch like this. Always thinking it was a rotary decoder but is not. It turns endlessly but only performs a 5-step fan speed level. If you look close there is a tiny ball in the one picture that has a solid copper ring. When turning, the ball goes around and then hits a stop but the knob can continue to rotate. Until it turns the other direction the ball then goes 320 degrees the other way and hits the stop again. The first picture drops onto the second picture piece.
I suspect, but could be wrong, as the it rotates it increases or decreases in resistance. But putting a meter on it, the resistance steps and isn't linear. I have 4 switches like this that no longer work and appear to have a short across the outer pins which makes contact simultaneously to both outer polls at the same time.


Alps%20Rotary%20%281%29%20%28Medium%29.JPG

Alps%20Rotary%20%284%29%20%28Medium%29.JPG

Alps%20Rotary%20%283%29%20%28Medium%29.JPG

Alps%20Rotary%20%282%29%20%28Medium%29.JPG



This is the circuit of how it works. It rotates and creates a momentary circuit closure to the fan speed stepper to increase fan speed clockwise and decreases speed counter-clockwise.

AC%20Circuit-2.jpg


I desperate to find a switch that can replicate this. Only other way to make a repair is to buy a whole used controller just to scavenge this switch.

Stu

It looks a !of like a variable resistor / potentiometer, also the manufacturer "Alps" is famous for making this type of component. The fact that the resistance doesn't increase or decrease evenly would seem to suggest that it's a log law potentiometer, the type used for volume controls.
 
As mentioned above...I have already tried several encoder switches and non have worked. Possibly because the EC11 /EC12 /EN11 series isn't quite the same as Alps used with this one. The duration of the square wave maybe is the issue.
I bought EC12E1220813, EN11HNM1AF15. I had to buy ones that were similarly shaped and sized.
I am willing to buy another series for testing as these are cheap if someone can get me another encoder series.
 
As mentioned above...I have already tried several encoder switches and non have worked. Possibly because the EC11 /EC12 /EN11 series isn't quite the same as Alps used with this one. The duration of the square wave maybe is the issue.
I bought EC12E1220813, EN11HNM1AF15. I had to buy ones that were similarly shaped and sized.
I am willing to buy another series for testing as these are cheap if someone can get me another encoder series.
When you turn it CW and CCW and you get both A and B turning on and off, it means that it must be rotary encoder.
Electrically they are all the same. All the 3 pins are open circuit in rest position and on rotation the 3 pins are short circuit for different duration.
 
Have you tried measuring resistance between the two end terminals and from the centre terminal to the end terminals while the shaft is rotated? It looks to me like it may be a potentiometer with (20?) discrete steps. I don't see two switches. I see the inner ring of contacts being the wiper, the outer ring being resistance taps, and the ball being a bridge (single switch) between inner and outer contacts. If that's the case, then a standard pot might well work as a substitute. Worth a try.
 
As the only spring I can see are the wipers, I think the ball lifts the wiper between switching moves, making no contact as you move.

C.
 
It looks to me like it may be a potentiometer with (20?) discrete steps.
If it is a pot that turns 360 degrees without a stop then at one point the speed of the fan will change from min to max, I can hardly see this acceptable feature.
 
Since I have done almost 400 of these heater control boxes to LED upgrades, I have a test box I use to verify all the functions. In this test, switch 3 tests the fan speed operation. Rotating to the left momentary turns a green LED on, rotating to the right turns a red LED on. (signifying "up" and "down" speeds) It is very distinct. Like either LED in either direction goes solid during rotation and the other off. So by rotating right and left it alternates from red to green. If the switch is bad, turning in either direction turns both LEDs on simultaneously. This means the switch has a short. Not sure where the short is within this switch as this is the first time I have actually dug into one.

When I tried several different Mouser/Digikey encoders, what happens is when I rotate the switch, the red and green LEDs overlap illumination. In other words, when rotating to the left both LEDs blink, not evenly, but staggered. Or when turned
in either direction the LEDs go Red/green --green/red with about .2 seconds delay. Which confuses the circuitry as it is getting an up/down speed signal at the same time. Whereas the good switch just blinks one color in one turn. I am sure this has something to do with a custom ALPS design in the square wave or whatever. I have a good friend who speaks Japanese and he called ALPS and sent an email of a picture and they said they do not have or make these anymore.

Bottom line is I have to buy a known good used box for over $100 just to dig out this switch for repair. Issue is these boxes new are discontinued and no longer available. SO even at $100 there isn't much alternates unless I can find a switch that works.
 
Have you tried measuring resistance between the two end terminals and from the centre terminal to the end terminals while the shaft is rotated? It looks to me like it may be a potentiometer with (20?) discrete steps. I don't see two switches. I see the inner ring of contacts being the wiper, the outer ring being resistance taps, and the ball being a bridge (single switch) between inner and outer contacts. If that's the case, then a standard pot might well work as a substitute. Worth a try.

Yes...when measuring one meter lead center tap and one lead on one side, as I rotate the meter momentarily reads a descending resistance, and a rising resistance on the other side. I cannot say exactly as I did this a year ago, but it was something like 4k-7k-10k-16k by each click on the detent and reverse dropping resistance the other direction. After each turn the resistance shows on the meter then goes open in almost less than 1 second.
 
It's a potentiometer (A custom one). Figure 7, here **broken link removed** would basically describe the operation and a possible way to engineer a replacement with a dual gang potentiometer. Of course, that likely won't fit in your space.

Volume controls have tapers because loudness isn't linear.

The two semicircular "bits" have a non-linear resistance from end to end.

Your assignment for now, it to:
1) Measure the end to end resistance of the semicircular bit
2) and the center to the pin. (put a probe on the end pin) and a probe on the center of the carbon track.
3) Look at the resistance from the center to the end of each carbon bit.

Do it in a way that we can follow.

In reality, you should be able to disassemble, clean and out it back together, but lets see what you have first.

There is a VERY SLIGHT possibility that you could replace this with an electronic potentiometer, encoder and a microprocessor to fit in the space. (the encoder would fit in the space). You must have the max current and voltage used for that to even be a possibility.
 
OK I will...I just did test 1) 2) 3) on a bad one so this wont be accurate. I will have to wait until I can de-solder a known good one. I do know that the readings for 2) 3) will be from 3K to 26K on one side and 26k to 3k on the other by rotating. But I will get the exact readings for each detent level. At one point in one direction it no longer changes resistance.



It's a potentiometer (A custom one). Figure 7, here **broken link removed** would basically describe the operation and a possible way to engineer a replacement with a dual gang potentiometer. Of course, that likely won't fit in your space.

Volume controls have tapers because loudness isn't linear.

The two semicircular "bits" have a non-linear resistance from end to end.

Your assignment for now, it to:
1) Measure the end to end resistance of the semicircular bit
2) and the center to the pin. (put a probe on the end pin) and a probe on the center of the carbon track.
3) Look at the resistance from the center to the end of each carbon bit.

Do it in a way that we can follow.

In reality, you should be able to disassemble, clean and out it back together, but lets see what you have first.

There is a VERY SLIGHT possibility that you could replace this with an electronic potentiometer, encoder and a microprocessor to fit in the space. (the encoder would fit in the space). You must have the max current and voltage used for that to even be a possibility.
 
So probably 30K. Some controls in "high-end" stereo systems had detents.

I don't really want to get your "hopes" up, but these https://www.onsemi.com/PowerSolutions/product.do?id=CAT5116 are a modern replacement. There are LOTS of design issues when using this device,

You might also measure the voltage across the device in the each extreme and "center". Take one of the end pins as a reference, the measure to the center and the other end. Also see if you can determine if one end of the device is connected to ground of the electronics.

I'll also think about rebuilding options. NO PROMISES.

Some ideas that are possible is to clean, evaluate and lubricate. Clean a pot up the best you can and take some new pics.
You DON'T want to use something like WD-40.

It's still a little puzzling. The brown thing is too dirty.
 
OK I lied...I do have a good one.

1) Open no continuity (bad one reads 270 ohms)
2) Probe center and other probe outside pin. Every click readings vary from 5.5m to 30m. Each randomly...They only show for about 1 second then go away to open. No readings if I rotate other direction. At one point rotating in same
direction I get to continuity readings, one then the other rapidly. I think that might be cause i am at the end of the rotation.

Inside view: This switch functions for only 5 speeds. The ball starts at one end of the wiper and detents 5 times to the other side of the wiper. Why it continues to rotate I do not know as it doesn't accomplish anything. There is some form of resistance
as it rotates but it displays once then goes away. I am going to try to clean it as this ones looks pretty dirty. But the main issue causing this to inop is because it does have continuity readings across the 2 outside pins where it should be open. Something
is causing this to read 270 ohms whereas it should be infinity. I will have to look and study real close up.

Pot%20Interior%20%28Large%29.JPG





It's a potentiometer (A custom one). Figure 7, here **broken link removed** would basically describe the operation and a possible way to engineer a replacement with a dual gang potentiometer. Of course, that likely won't fit in your space.

Volume controls have tapers because loudness isn't linear.

The two semicircular "bits" have a non-linear resistance from end to end.

Your assignment for now, it to:
1) Measure the end to end resistance of the semicircular bit
2) and the center to the pin. (put a probe on the end pin) and a probe on the center of the carbon track.
3) Look at the resistance from the center to the end of each carbon bit.

Do it in a way that we can follow.

In reality, you should be able to disassemble, clean and out it back together, but lets see what you have first.

There is a VERY SLIGHT possibility that you could replace this with an electronic potentiometer, encoder and a microprocessor to fit in the space. (the encoder would fit in the space). You must have the max current and voltage used for that to even be a possibility.
 
Measure the naked elements. No slider. The left white annotation, to just before the green attachment post. Then halfway from the laft-white annotation. Do the same on the right side.

Just want to get an idea of the max resistance and the arrangement.
 
Measure the naked elements. No slider. The left white annotation, to just before the green attachment post. Then halfway from the laft-white annotation. Do the same on the right side.

Just want to get an idea of the max resistance and the arrangement.

It reads 0 ohms to any part of that path. I think I may have made an error...I took apart another switch and have possibly found out that the ball bearing actually fits in a cradle on the back as shown. The 2 copper paths that meet on the bottom tab area on not connected. I think the ball bearing is what "joins" the 2 copper paths. Maybe by rotating resistance changes. I can grasp how it works as I am not sure where the resistance paths really are.

Pot%20Interior%20REV%20%28Large%29.jpg
 
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