I know this is no longer available, I got the last one in the UK.
I’ve just soldered the board. I’ve followed the instructions that state to solder two sections of 9.5cm copper wire to the cropped 3mm sensor and then twist the wire before applying the heat shrink. Am I being thick here, but surely by doing this I am shorting out the sensor?
I have connected a 12v supply and all I get is an ERR message of the display. Someone help please? My copper wire supplied was not varnished
Check if the sensor is not short-circuited.
Check the complete assembly for assembly errors.
Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side)
then we can take a look and provide some feedback.
[quote=“VEL417”]Check if the sensor is not short-circuited.
Check the complete assembly for assembly errors.
Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side)
then we can take a look and provide some feedback.[/quote]
This is what I don’t understand. By twisting the wires together, of course the sensoris short ccircuited, the thin copper wire provided has no insulation. Should I redo it with insulated wire, but doesn’t thicker wire affect the readout?
The supplied wire is winding wire and it is insulated.
If there is any doubt, please check with a multimeter.
[quote=“VEL417”]The supplied wire is winding wire and it is insulated.
If there is any doubt, please check with a multimeter.[/quote]
I appreciate that but mine didn’t have varnish on it, it was plain copper wire. I think I’ll have to source some and start again. I dont actually have my multimeter anymore, believe it or not I left it on a ship. It was an Ex Ecom, cost a bomb.
[quote=“VEL417”]Check if the sensor is not short-circuited.
Check the complete assembly for assembly errors.
Sorry, this forum does not allow picture uploads
If you can provide LINKS (e.g. by using a free online picture base) to HI-RES and SHARP pics of your assembly (both solder- and component side)
then we can take a look and provide some feedback.[/quote]
Hi
I’ve stripped back the heat shrinking and untwisted the wire. I’ve removed the additional wire and seperated any chance of a short circuit. I’,m still getting the error message. It reads ER.R, the dot is illuminated on DY2. Any ideas?
I’ve checked the circuit for errors and all seem ok. All soldering joints look good too.
Sorry, this can be anything.
It is very hard to troubleshoot without being able to examine your unit.
I repeat, if you post detailed pics of both PCB sides, we can have a look.
[quote=“VEL417”]Sorry, this can be anything.
It is very hard to troubleshoot without being able to examine your unit.
I repeat, if you post detailed pics of both PCB sides, we can have a look.[/quote]
Here are some pics i uploaded. Let me know if its something silly. Thanks
flickr.com/photos/92740403@N … otostream/
flickr.com/photos/92740403@N … otostream/
flickr.com/photos/92740403@N … otostream/
Thank you
Assembly looks OK as far as we can see.
We managed to dig up a working sample of this obsolete kit.
If we short the sensor or if we leave it open, we get the exact same behaviour.
We noticed that you have cut the sensor wires very short, which could have caused overheating during soldering.
Try replacing the sensor with a 2K2 (more or less) resistor. This is the approx. value the sensor shows at room temperature.
If the display then shows figures instead of ER.R, the sensor is most likely defective.
If the problem remains the same, then there must be a problem in the sensor part of the circuit.
Start by checking if a PWM arrives at pin 13 of the processor (IC3) and move downstream to locate the source of troubles.
[quote=“VEL417”]Assembly looks OK as far as we can see.
We managed to dig up a working sample of this obsolete kit.
If we short the sensor or if we leave it open, we get the exact same behaviour.
We noticed that you have cut the sensor wires very short, which could have caused overheating during soldering.
Try replacing the sensor with a 2K2 (more or less) resistor. This is the approx. value the sensor shows at room temperature.
If the display then shows figures instead of ER.R, the sensor is most likely defective.
If the problem remains the same, then there must be a problem in the sensor part of the circuit.
Start by checking if a PWM arrives at pin 13 of the processor (IC3) and move downstream to locate the source of troubles.[/quote]
Thanks, I will give that a try and let you know how I get on. This wont be the first time I’ve damaged a sensor if it is. The sensor on the universal temp kit used on the big digital clock gave similar irregular readings, and this was after soldering wires onto it. The instructions tell you to crop the legs of the sensor to 3mm, I guess to avoid shorting them out when twisting the windings wire. cheers
[quote=“VEL417”]Assembly looks OK as far as we can see.
We managed to dig up a working sample of this obsolete kit.
If we short the sensor or if we leave it open, we get the exact same behaviour.
We noticed that you have cut the sensor wires very short, which could have caused overheating during soldering.
Try replacing the sensor with a 2K2 (more or less) resistor. This is the approx. value the sensor shows at room temperature.
If the display then shows figures instead of ER.R, the sensor is most likely defective.
If the problem remains the same, then there must be a problem in the sensor part of the circuit.
Start by checking if a PWM arrives at pin 13 of the processor (IC3) and move downstream to locate the source of troubles.[/quote]
yes I soldered a 2k2 resistor across the SENS terminal and I still get Er.r
I don’t have the facilities to check for pulse width modulation. Perhaps I will just have to replace one component at a time to see if there is any change.
If you set your multimeter to ‘AC volts’, you should be able to determine if there is a PWM or not.
I’ve ordered a multimeter as i lost my first one. It’s like working in the dark without one. I’ll let you know once I can get my new one.
Continuing with the fault finding of the K6003 I have measured the voltage at pin 13 of the PIC16C54C IC3. Measure in AC volts to OUT it fluctuates between 4.8 and 5.2v. When the negative lead is in air, I’m getting constant 15v and when to negative or positive supply terminal it fluctuates slightly around 2.2v.
Any thoughts on how to progress? I’d love to get this sorted, it’s the only kit that hasn’t worked so far. I have spare sensors but as we tried the resistor I haven’t bothered swapping the sensors.
Thanks
There is something very strange going on here.
I decided to change the sensors. I took off the old sensor and checked continuity and resistance, ensuring the winding wire is made and the resistance of the sensor is around 1K8. I attached the new sensor directly to the pins and still Err.
I accidentally touched both sensors to the terminals I now get a reading, albeit its out, but still a reading. I have now had both sensors attached for about 15mins and I’m getting a stable read out. I’m struggling to reason why this would happen and obviously in this condition I cannot calibrate it freezing cold water. Any ideas?
[quote=“postmaster-general”]There is something very strange going on here.
I decided to change the sensors. I took off the old sensor and checked continuity and resistance, ensuring the winding wire is made and the resistance of the sensor is around 1K8. I attached the new sensor directly to the pins and still Err.
I accidentally touched both sensors to the terminals I now get a reading, albeit its out, but still a reading. I have now had both sensors attached for about 15mins and I’m getting a stable read out. I’m struggling to reason why this would happen and obviously in this condition I cannot calibrate it freezing cold water. Any ideas?[/quote]
I think I’ve figured out what is wrong with this. Mine is set to °F although I think this has nothing to do with it. I thought it odd that when two sensors are connecting in parallel that I should start to get a read out. And that when connecting one sensor (3 different ones) and a resistor as you suggest that I still get Er.r displayed. Perhaps this is now a redundant model, and I got the last one from Velleman in the UK, but it’s not a cheap product and I’m determined to get it working. I realized that the offset was so far wound round that is twas reading way too high, but putting two sensors in half the signal. By winding it all the way back I started to get a reading with just one sensor.
So tonight, I will prepare just one sensor with the additional wire and freezing glass of water and attempt to zero it at 32° as suggested in the instructions. I will let you know how it fairs. Pity Velleman didn’t supply a sticker with Fahrenheit or perhaps us British should finally get used to °C.
Just to confirm that the K6003 is now working fine. Reading the small print it says that the thermometer ranges from -50 to 150C, however, if set to Fahrenheit (a different resistor is used) then the maximum temperature is 150°F which is 65.6°C. When initially powering up the unit, the pots wouldn’t need to be wildly out to be out of range. The instructions don’t mention that the Er.r can also mean out of range. Even when fitting the resistor, it led us to believe that there was a fault with the circuit. I calibrated the unit 4 times and it seems to be spot on so very pleased.
Thanks for your help regarding the K6003.