Need help with mystery component - Page 1
Forum section: electronics / projects

author: Stevewatr
author_rank: Newbie
timestamp: November 09, 2024, 05:16:35 am
content: Hello. New member here. I am working in a control unit for a Terex TB85 manlift. The joysticks are proportional controls. That is to say, the further they are pushed, the faster things move. The joysticks assemblies use microswitches and some type of mystery device to achieve this. Each device has one switch in series with the device so the device is out of circuit until the stock is moved. A sector gear rotates a opinion gear on the device. So the device direction of rotation of the gear tells the system what direction the stock is being pushed, and how far it is pushed. At first I thought it was a potentionometer, but I am unable to get any resistance reading. It would also be unlikely a pot because how could they controller know what direction the shaft was roatating?The box was made by OEM controls but apparently they no longer offer support on these. The component in question appears to be called a "digi-sensor". I find random listings of them for sale ranging in price of 3 to 6 hundred dollars.Does anyone know what type of component this is and how it can be tested?The picture as the closest thing to my device except mine appear to be a grey composite material for a body.

author: Poroit
author_rank: Frequent Contributor
timestamp: November 09, 2024, 05:59:45 am
content: G'day Stevewatr,It looks like Honeywell was involved with this product at sometime.Can the unit be opened?Are the two LED'S viewable on the Control Console?

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: November 09, 2024, 06:33:25 am
content: I'd suspect it's a20 mA current loopdevice.

author: Salitronic
author_rank: Contributor
timestamp: November 09, 2024, 08:40:59 am
content: Joystick sensor like that are normally a 4-20mA loop powered sensor.Red wire is 12V, black wire is the measured return current.The leds indicate direction and centering.Found the attached manual, might be useful.

author: Poroit
author_rank: Frequent Contributor
timestamp: November 09, 2024, 12:49:03 pm
content: The two responding members have done wellYou should be able to test the modules by connecting a multimeter set to mA DC in series with the Red wire & microswitch.Rotate the pot and you should see the the mA vary.

author: Stevewatr
author_rank: Newbie
timestamp: November 09, 2024, 12:58:48 pm
content: Wow! Thank you so much. The attached manual has a great clear concise explanation of how the Digisensor works. Should be fairly easy to determine if they are working correctly, now that I know how they are supposed to work.

author: Stevewatr
author_rank: Newbie
timestamp: November 09, 2024, 01:05:35 pm
content: Completely sealed units. Potted in. I assume this is to help withstand the harsh enviroment. These machines are designed to be outside year round, and used in all types of weather. The device is mounted in a way that would make the LRD's hard to see even with the control box open. I suspect they are only for checking function. I will look again today, but I do not recall seeing LEDs on my units. Mine do not have metal cases. They are grey, and sealed with potting material.Now that I have a manual from Salitronic, I should be able to figure it out.

author: Stevewatr
author_rank: Newbie
timestamp: November 09, 2024, 01:59:44 pm
content: Well hopefully my digi sensors are all okay, since they are ridiculously expensive.I bought the machine AS IS, and it has some control issues from the arieal control station. Since the ground controls work okay, I decided to open up the control box, and found that there was some wiring with damaged insulation, looks like wires had been pinched in the joystick gears at times. I also found 2 bad microswitches, and sogns of some ham handed repair attempts. One joystick was not wired correctly at the microswitches. One switch only had one wire attached, and the other had three (using both the NO and NC taps ).Today I will reinstall the box, and test it out. Now that I know a little more about how they work, especially the "Superflex" board the sensors interface with, it should just be a matter of watching the 3 status LEDs on the board to see if the joysticks are working.Thanks again to all who responded. I will post an update after testing this weekend.