Tachometers with hall proximity sensor question

[Firstram]

Did you stick your tongue on it to see if it was good?

 

[Suzuki4evr]

.........I did. But asn't that the volt meter of yesteryear????. It was actualy a bit on the weak side, according to my tongue,but I don't have a multimeter to make sure. Tomorrow will be busy,but I ask my father inlaw to test it sometime.

 

[B2]

Hi, Do I understand correctly from your latest comments? I do not understand the meaning of your phrase "...reading shows quickly...." Because of this I am still unsure if your sensor or display are good or not.

Does this mean the reading changes, or are you saying it just goes back, to zero because you are no longer turning the spindle? It should read zero when there is no motion!

Please post the model number of your sensor as well as your display. For the sensor this is the number on the paper wrapping around the sensor. I am confused about these. In your post it appears that you showed a picture of a label which says LED, 8-24V, and 30mA. This implies your display/meter to me and at the top of this post that the "tachometer is 30mA." So this would imply that the display can work from a 9V battery for quite a while. I searched on "cf5135c-z manual" the number on this label. There are several references to this number in the search. You might want to do the same to see if you are hooking things up correctly. Is this your display and sensor? https://usefulldata.com/led-spedometer-cf5135b/ I cannot see the Hall sensor number well in your posts. Or "attach" a pdf of the specifications of each. This way I maybe able to look them up for sure and so will know for sure what voltages, currents and wiring these have. Without the specs we are all just guessing a bit. Use the "Attach files" button at the bottom of the HM window rather than just drag and dropping the files so that the images can be downloaded in full format.

Questions:

1) 24 volts to the display power input show all zeros. This is the VFD 24V source (supply)?
2) 9Volts + terminal to the power input to the Hall sensor and the Gnd input of the Hall sensor is connected to the 9Volt battery Negative terminal?
3) The Hall signal line output is to the display signal input?
4) The 24V Ground of the VFD is tied to the negative terminal of the battery. (common grounds.)

5) Without the motor turned on you can move the spindle by hand and the display shows numbers? (no connections have been changed?) if so this implies that the sensor is sending signals. A good sign.
6) When the motor is turned and the spindle rotates, even at slow rates) the display no longer shows numbers , just dashes? (no connections have been changed?)

7) Does your display instructions say anything about what all dashes means? Does it possibly mean that the spindle is turning too fast? Not enough power to run the display?

If I understood your last posting correctly, then it sounds like something about the display is not right. Maybe the 24volt supply fails when the motor is turned on. If the display will work with 9v then you could attache the display power line to a 9V battery as well. If not then maybe a 12 volt supply. Some displays do now want to work on 24 volts and tend to burn out at 24 volts. My latest one wants a supply voltage between 8volt and 12v. This may also be true for the Hall sensor.

There is the possibility that you connection between the 24V supply and the display is poor or intermittent. If the contacts are bad, it may be that went the motor is not running there is enough power arriving at the display supply line that the display lights up, but when the display electronics are working there is not.

If you are going to do electronics you should really purchase a Volt-Ohm-Meter, VOM and read the instructions on how to use them. Even the very cheap ones and will allow you to measure voltage, current, and resistance. I do not know where you live, but even Harbor Freight has various models. If you had one you could measure the battery terminal voltage and see if the battery was bad. A 9Volt battery puts out about 9+volts when fresh. It will still be working when it puts out 8 volts, and under load (current flowing) the terminal voltage will drop, but alkaline batteries, like Duracell, work very well and are reasonably strong. Really cheap batteries are commonly Carbon Zinc technology and do not put out as much current nor do they have the long shelf life of alkaline batteries..

 

[B2]

Amazon has lots of multimeters, VOM. You do not need the best. $25 is plenty to spend, but if you spend $35 you can also get a counter in the meter. Harbor Freight use to have one that was only about $5. It works but tends to break. I must have 6 or 7 VOMs so that I do not have to go search for one when needed. Sometimes I hook up two or three so that I can measure current and voltage at the same time.

At Amazon, pick one out that does not have too many bad reviews.

 

[WobblyHand]

@B2 some of his options may be more limited, since the OP lives in South Africa. Doubt there's a Harbor Freight there!

 

[B2]

Wow! I did not pick up on that! Thanks. He can probably get parts from China or India just about as fast. However, who knows for sure about Amazon. They seem to be everywhere!!! They do seem to ship to S A, but not for free and it looks like about 18 days.

Anyway, I google mapped Wellington. Wine Country! They have to be some shipping in and out of there all the time.

Michael, where did you get your Tachometer kit from? How long did it take to ship?

 

[B2]

ebay?

 

[Suzuki4evr]

I do not understand the meaning of your phrase "...reading shows quickly...." Because of this I am still unsure if your sensor or display are good or not.

Sorry for being a bit unclear,I apologise. I meant there is a brief reading on the display when turning by hand and then it returns to zero.

Please post the model number of your sensor as well as your display. For the sensor this is the number on the paper wrapping around the sensor. I am confused about these. In your post it appears that you showed a picture of a label which says LED, 8-24V, and 30mA

It is infact an ebay product. I usualy wait about 20 to 40 days,but this one was about 50.

Is this your display and sensor? https://usefulldata.com/led-spedometer-cf5135b/

Yes it looks the same.

Questions:

1) 24 volts to the display power input show all zeros. This is the VFD 24V source (supply)?
2) 9Volts + terminal to the power input to the Hall sensor and the Gnd input of the Hall sensor is connected to the 9Volt battery Negative terminal?
3) The Hall signal line output is to the display signal input?
4) The 24V Ground of the VFD is tied to the negative terminal of the battery. (common grounds.)

5) Without the motor turned on you can move the spindle by hand and the display shows numbers? (no connections have been changed?) if so this implies that the sensor is sending signals. A good sign.
6) When the motor is turned and the spindle rotates, even at slow rates) the display no longer shows numbers , just dashes? (no connections have been changed?)

7) Does your display instructions say anything about what all dashes means? Does it possibly mean that the spindle is turning too fast? Not enough power to run the display?

#1-Yes
#2-Yes
#3-Yes
#4-Yes (so two wires to 9V -? 24CM and gnd input of sensor? Still nothing on display. Maybe battry is defective)
#5 -Yes (when conected to VFD 24V and CM).
#6-Correct
#7-No Instruction manual.

 

[Suzuki4evr]

@B2 some of his options may be more limited, since the OP lives in South Africa. Doubt there's a Harbor Freight there!

Nope. No Harbor Freight

 

[Suzuki4evr]

Anyway, I google mapped Wellington. Wine Country! They have to be some shipping in and out of there all the time.

Michael, where did you get your Tachometer kit from? How long did it take to ship?

Lovely wine valley yes and beautiful. Yes I got it from China via EBay. I will get a another battery,but my workload is a bit much to get away and I am in the middle of renovating my bathroom.