Digital Tachometer for record player (LCD display)

I thought I would post pictures of my implementation. Thanks again Pyramid, Tauro and all those who assisted getting this done for us.
I have 2 inputs at the back which are switched from the upper toggle switch on the front panel. The battery at the back is for when I move it to the other system. I use a wired snap on 9v connector wired to a female DC plug to go to a 9V plugback for normal use. I use a proximity sensor with a 3.5mm stereo plug.
The arduino clone, display and sensor cost me AUD30 The box and plugs another $20 or so.
Sorry about the display but it got lost in the glare. The display cutout was a bit of a hatchet job.
I can post links to the parts I bought to help Aussie builders if any one is interested.
Regards,
kffern



Great implementation.
I guess we both used the same case.
Here is mine:

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I recently purchased these aluminum enclosure from China and just completed remounting my MC Step ups from an old project box and it looks good. I'll use the other one for this Arduino Tachometer. I will have the front panel machined to mount the LCD display.
 

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I´ve tried to make the connection of the Tachometer with the Falcon PSU, with no success until now. I rewired the little TTL > RS232 board for different possibilities but I can´t get to make that little decimal dot of the Falcon display to blink.
BUT...
After I gave up, I noticed that the Falcon PSU, working alone, with the motor/belt bad positioned to give a speed around 33.15-33.20 RPM, remains in that speed if not manually corrected on the Falcon. THEN, when I reconnect the Tachometer to the Falcon, even without the decimal dot blink to confirm a RS232 connection, it slowly gets to 33.33~ RPM and keeps on this speed limit!!!
I tried this experiment for three times with the same results!
SO... Is it possible that the Falcon PSU is "talking" with the Tachometer but not blinking the decimal dot on the display????
 
SO... Is it possible that the Falcon PSU is "talking" with the Tachometer but not blinking the decimal dot on the display????

I don't think that's possible.

The decimal point on the Falcon does not blink when it is receiving data from the tach (the Falcon also does not talk with the tach, the conversation is one direction only), it blinks only when it is applying correction. It does not apply correction for errors smaller than 0.005 RPM.

The Falcon does not apply correction on the first 4 readings it receives from the tach; it allows the platter speed to stabilize before applying correction. If it is applying correction, the decimal point will blink.
 
Hi CoolMaster,

Can you point me to the ebayer you got the cases from? Many thanks.

Kevin

Hi Kevin,
I bought the case from Aliexpress instead of Ebay which is now very popular to buy these kind of products or other goods from my side of the world.
Free ship 1205 Black Full Aluminum Audio Amplifier Enclosure/ Mini AMP Case/ Preamp Box/ PSU Chassis-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
I'm glad these worked out very well for me and quality is to my expectation.

Lee
 
Hi Lee,
Highly appreciated, many thanks.
Kevin

I also sought and purchased speed controller chassis/enclosure from Aliexpress vendors. Some vendors seem to be on Ebay and less choice.

I'm not promoting Aliexpress, its merely my prime choice for wider choice and perhaps surer delivery to my country than Ebay which I find more more perilous to address in case of any product dispute. I have suffered non delivery issue with Ebay seller sometime in the past, very reluctant to face that again.
Sorry if off topic.

Lee
 
Definitive version is complete, didn´t managed to make it "talk" to the Falcon PSU, but the speed stability is so much better with the Falcon that using the tachometer just to set proper speed is enough to achieve an excellent result.
I don´t know if my TTL>RS232 board is not working properly, I tried all combinations and no way to see the decimal point blink on the Falcon..
Maybe I will get another board in the future, but it was so hard to squeeze everything inside this little case that now I want to leave it as is.
Thanks everyone for all the help and for sharing this great project with us!!!

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Hi Lee,

Many thanks for that. I have in fact just gone through that problem. Non delivery/lost goods?/returned to sender by local PO? but nothing to be found out. I'm just $55 shy of funds, and can't go further with the SG4 project. Aaargh!

Had to order from alternative vendor, but I am now tracking the goods very carefully. Will probably use AliExpress in future.

Kevin
 
This is how I'm mounting the Arduino and display into a nice aluminum enclosure. (the same type I used for mounting my MC SUT earlier) I mounted it on a blank PCB which I can slide in to fit.I soldered the power, sensor wires directly underneath the Arduino to be permanent. I may do the same for the display wires after I get the front panel machined out for the LCD.
 

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Curiosity....

Hi,

I’ve managed to finish the tach and I’m delighted with it. Now I can adjust the SG4 with precision. As a side effect, I have found that the turntable speed is slower when the arm is in the first track, 33.333 at the middle of the disc and towards the end is higher i.e. 33.339 or 33.340. Any ideas?

Thank very much Bill for this gift. I appreciate.

Regards,

Jorge Castellano
 

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Correct adjustment of SG4

The change in speed is caused by stylus drag on the record. It is more pronounced at the beginning because the drag has more leverage at a larger radius.

You should be able to see the amount of drag between stylus up and when it is on the record.

Hi,

Thank both for the answers... I appreciate.

So in order to make a more or less permanent adjustment of the SG4, should I adjust for 33.333 without the arm? Then asume that at the beginning of the record is a bit slower and at the end of the record faster but without much influence in the reproduced music?

Regards,

Jorge