Rotary encoder switch info needed


Ed Breya
 

I have a few old 40-position absolute encoder switches that probably came from some 40-channel CBs I junked out years ago. One of my projects is a special time mark/clock/risetime-check generator type thing to be built as a custom 7K plug-in. I need about 32 (5-bit) positions or more to control all the possible 1-2-5 sequence ranges from 1 nSec (1 GHz) to a few Sec (<1 Hz), so these 40 (5+-bit) spot ones would be great, and provide spare positions and allow absolute settings to be kept. The problem is to figure out how they're encoded. Regular binary or gray codes are often used for general purpose switches, but I don't know if these are standard - they may be specially coded for the original CB applications to synthesize the 40 channels, directly working the sub-parts, rather than telling a processor the setting. To make things worse, I can't find any data other than photos of various ones for sale. The switches look pretty nicely made, probably Japanese brand, called "Accord," and the base part seems to be "PSS-23." I found a picture of one linked below. Finally, to make matters worse yet, try searching something "accord" without the car showing up.

https://www.google.com/search?q=%22pss-23%22+rotary+encoder+switch+pinout&client=firefox-b-1&biw=1543&bih=896&tbm=isch&source=iu&ictx=1&fir=IL0p-WuzomTBkM%252Cb3EAdqKig2lPzM%252C_&vet=1&usg=AI4_-kQiLgu2etTwZOfkhRONN_AKwfwH1w&sa=X&ved=2ahUKEwjkwNnRn6LwAhWaHzQIHfPcAQYQ9QF6BAgPEAE#imgrc=eacNkAkEQZA9oM&imgdii=90g6KZ-VLSh-3M

These apparently came in various position counts including 12 and 24, and of course 40, evidenced by the ones I have. The pin pattern seems to be fixed, with four layers of 5 pins per section, which would give up to 4-bits each, and it looks like the sections are paired, with the same kind flipped and attached. So, each pair set could be enough to provide at least 32 unique position codes, or lots more, depending on the coding arrangement. I have three pieces that look like the picture, with four rows of pins (two pairs), and two larger of the same style, with six rows of pins (three pairs). These bigger ones may have extra stuff for driving say, a two-digit LED 1-40 count readout.

Anyway, it would be very tedious to ohm out all the possible pin codes and even identifying which pin is which, so a data sheet of some sort would go a long way toward figuring it out, even if the coding is special. I'd appreciate if anyone has any info about, or knowledge of these switches. A long shot may be if there are any specific CB synthesizer designs that happen to use these switches - they must have been fairly common thirty or so years ago, for me to have salvaged out five pieces. The switches are held together with melted-head plastic pins, so can't be readily disassembled for inspection - it would be no big deal otherwise. It may become necessary to cut and goop as a last resort.

Yes, I know it would be simple enough to do an incremental up-down coder/counter deal, but I like the idea of having the absolute position coding - no remembering or resetting needed. That's what I was planning on before I discovered these little gems in the junk department. BTW the time and frequency will display on-screen only, so there's no need for 40 tiny knob marks and labels.

Ed


Ed Breya
 

That link may not show properly. I have put a picture in the photos department, just in case.

Ed


Brian Cockburn
 

You're right, trying to work it out with an Ohm-meter will take forever and possibly cause brain damage. So it sounds like a job for an Arduino (Nano). It can scan all the possible connections quickly and serial.print those that are connected. Then wait for you to click the switch and repeat the scan/print procedure.


SCMenasian
 

It looks like this encoder is arranged in 4 decks. My approach would be to look for a unique pin on each deck which is switched to more than one other pin as the shaft is rotated. This should be easy with an ohmmeter. If successful, I would assume that that pin is a common and connect it, through a resistor, to a voltage supply. Then, I would connect an LED from each of the other pins to ground (with the correct polarity. of course). apply the voltage and observe the result as the shaft is rotated. If you're lucky, this will give you what you want for each deck.


Jim Strohm
 

One important thing to remember is that CB channels below 24 are NEITHER contiguous nor numerically ordered. So to repurpose these switches, you might set up an LED matrix to show continuity per switch position.

I’ve seen a few switch tables for CBs but it was decades ago. I’m pretty sure but not positive that all 40-channel CBs used a switched digital PLL and VCO arrangement and not the “rock crusher” crystal mixer common with most 23-channel rigs.

FWIW the digitally controlled rigs used an octal +1 switch matrix on the VCO, but some had hex inputs. Some also had a ROM to block non-permitted frequencies. Defeating the ROM was non-trivial and required significant surgery.

If CBTRICKS.com is still online, you may be able to garner more info there. Especially if you are converting CBs to other bands, you want to buy their DVD set if it’s still available.
It’s much faster to search a DVD than to download from their website, especially since some misguided anti-CB dweebs continue to engage in DoS attacks against them, 30 years after the CB wars ended.

73
Jim N6OTQ

Sent from my quenched-gap spark transmitter.


John Kolb
 

If the switch was intended for use in a CB radio, it may be encoded to drive the inputs of a specific synthesizer IC, so would take a logic to convert to 1, 2, 3, ... 40 signal.

John

On 4/29/2021 7:16 AM, Jim Strohm wrote:
One important thing to remember is that CB channels below 24 are NEITHER contiguous nor numerically ordered. So to repurpose these switches, you might set up an LED matrix to show continuity per switch position.
I’ve seen a few switch tables for CBs but it was decades ago. I’m pretty sure but not positive that all 40-channel CBs used a switched digital PLL and VCO arrangement and not the “rock crusher” crystal mixer common with most 23-channel rigs.
FWIW the digitally controlled rigs used an octal +1 switch matrix on the VCO, but some had hex inputs. Some also had a ROM to block non-permitted frequencies. Defeating the ROM was non-trivial and required significant surgery.
If CBTRICKS.com is still online, you may be able to garner more info there. Especially if you are converting CBs to other bands, you want to buy their DVD set if it’s still available.
It’s much faster to search a DVD than to download from their website, especially since some misguided anti-CB dweebs continue to engage in DoS attacks against them, 30 years after the CB wars ended.
73
Jim N6OTQ
Sent from my quenched-gap spark transmitter.