Author Topic: Weller WE1010 conversion for WSP80 handle (Read 3009 times)

badyl00 · « **on:** February 25, 2021, 11:29:23 am »

Hello. Looking for help with conversion WE1010 station to work with WSP80 handle. Originally it works with WEP70 handle. It have different temp sensor inside. I added original schematic from board. Next i disconnected op amp output from uC and add 0-5V power supply. Then I measured changes voltage on uC input to temperature on LCD display. Not sure about op amp type. It have marking YG69 but in weller works similar MCP types. On next image i drawn schematic from WSD81 originally working with WSP80. Maybe someone can calculate how to change values near op amp to get work WE1010 with WSP80 handle ?

wraper · « **Reply #1 on:** February 25, 2021, 11:43:44 am »

What different sensor? Did you make any measurements of sensor? Circuit looks like it uses thermocouple. If other type uses resistive sensor, there is no simple conversion. EDIT: did not notice there was a second circuit. Yeah it looks like one uses thermocouple but other uses resistive sensor.

badyl00 · « **Reply #2 on:** February 25, 2021, 11:47:00 am »

Only found this:
https://www.old.telec16.fr/content/electronique/fer/fer.html

Think both types are PTC. I don't have WEP70 to take measures.

wraper · « **Reply #3 on:** February 25, 2021, 11:49:35 am »

Quote from: badyl00 on February 25, 2021, 11:47:00 am

Only found this:
https://www.old.telec16.fr/content/electronique/fer/fer.html

Think both types are PTC. I don't have WEP70 to take measures.

It says WEP70 uses thermocouple.

wraper · « **Reply #4 on:** February 25, 2021, 11:53:45 am »

IMHO the only option to not make it overcomplicated and working decently is adding proper amplifier for sensor type and MCU. Which will then read the voltage from it's ADC, calculate conversion and output PWM which is then smoothed and used instead of output from original sensor amplifier.

badyl00 · « **Reply #5 on:** February 25, 2021, 12:03:58 pm »

Quote from: wraper on February 25, 2021, 11:49:35 am

It says WEP70 uses thermocouple.

It says temperature sensor is unknown. Think changes of resistors can solve problem but don't know how to calculate values. PCB is prepared to changes because have not mounted resistors.

Oryginal looks like this:

wraper · « **Reply #6 on:** February 25, 2021, 12:08:01 pm »

it says thermocouple type with question mark which, as I understand, means unknown thermocouple type and 3 Ohm. 3 ohm is basically impossible for resistive sensor. Nor schematic could possibly work with resistive sensor.

badyl00 · « **Reply #7 on:** February 25, 2021, 12:18:24 pm »

Think 3 ohms is wrong measure. I can add a variable resistor on input of station and take characteristic of Rin/Temp on display.

wraper · « **Reply #8 on:** February 25, 2021, 12:20:56 pm »

Why would it be wrong? It's a completely reasonable resistance for thermocouple. Do you understand what thermocouple is?

badyl00 · « **Reply #9 on:** February 25, 2021, 12:35:23 pm »

Quote from: wraper on February 25, 2021, 12:20:56 pm

Why would it be wrong? It's a completely reasonable resistance for thermocouple. Do you understand what thermocouple is?

Yes understand.

wraper · « **Reply #10 on:** February 25, 2021, 12:40:09 pm »

So, to make it work in purely analog way, you need to somehow linearize output voltage, as it's not linear at all. To make it basically linear as with thermocouple. And if possible replace built in temperature sensor with fixed resistor. Still accuracy over the range will not be very good.

badyl00 · « **Reply #11 on:** February 25, 2021, 01:56:36 pm »

Quote from: wraper on February 25, 2021, 12:40:09 pm

So, to make it work in purely analog way, you need to somehow linearize output voltage, as it's not linear at all. To make it basically linear as with thermocouple. And if possible replace built in temperature sensor with fixed resistor. Still accuracy over the range will not be very good.

But in WEP70 opamp output voltage is linear to temp and for WSP80 same. So it's not possible to change starting point of characteristic and slope of output V/Temp ? Maybe I thinking wrong.

wraper · « **Reply #12 on:** February 25, 2021, 02:10:59 pm »

Quote from: badyl00 on February 25, 2021, 01:56:36 pm

But in WEP70 opamp output voltage is linear to temp and for WSP80 same.

Did you actually measure it?

badyl00 · « **Reply #13 on:** February 25, 2021, 02:19:43 pm »

For WSP80 characteristic is on internet and for WEP70 I wrote values in table. Looks linear. Op amp in both schematics works in linear mode i think.

https://www.edaboard.com/threads/schematics-from-weller-pu81-power-unit-for-wsp80.90461/

wraper · « **Reply #14 on:** February 25, 2021, 02:46:01 pm »

If it's really linear, this should be fairly precise if I did no mistakes with calculations and figures on internet were correct (assuming your measurements were done at 20^oC ambient temperature). To make it not drift because of ambient temperature change, you should find temperature sensor on PCB. If it's a thermistor, then measure it's resistance at room temperature and replace with fixed resistor. EDIT: for some dumb reason I assumed your temperature/voltage table was in Fahrenheit. So deleted schematic and will recalculate the values.

wraper · « **Reply #15 on:** February 25, 2021, 05:06:03 pm »

badyl00 · « **Reply #16 on:** February 25, 2021, 07:19:31 pm »

Sorry. All temperatures are in celsius. Schematic opamp_we1010 need to be changed . Schematic Wsd81 I only attached to look how its build to work with wsp80 handle in other station.

wraper · « **Reply #17 on:** February 25, 2021, 07:41:40 pm »

Quote from: badyl00 on February 25, 2021, 07:19:31 pm

Sorry. All temperatures are in celsius. Schematic opamp_we1010 need to be changed . Schematic Wsd81 I only attached to look how its build to work with wsp80 handle in other station.

You need to modify WE1010 amplifier to be the same as WSD81, just with different resistor values. There is no way to keep it as is and use fundamentally different type of sensor.

badyl00 · « **Reply #18 on:** February 25, 2021, 08:44:20 pm »

Can you add equations to you calculations ?

wraper · « **Reply #19 on:** February 25, 2021, 08:59:40 pm »

Sensor Resistance Rsens = 19.96*0.113*temp. Input voltage Vin = 5V * Rsens/(Rsens + R1). Output voltage Vout = (Vin-Voffset)*Gain. Voffset = 0.0723V, divided by R2, R3 to get approximately the same voltage as Vin at 22^oC, Gain = 17.6. For R4 calculation to get required opamp gain, it can be approximated that R6 is connected to GND since R2, R3 divider has negligible output resistance.

antek133 · « **Reply #20 on:** March 17, 2023, 07:02:30 am »

Witam. Czy poruszony temat został rozwiązany, czy wszystko działa poprawnie ?

mb.raghavendra@gmail.com · « **Reply #21 on:** November 28, 2023, 05:31:04 pm »

Hi All,
Looking for help with conversion of WSD81 station to work with WEP70 handle(Iron). . . I have added schematic for WSD81, Temp to ohm measurement of WEP70 .
Can someone calculate how to change values near op amp to get work WSD81 with WEP70 handle?

Also observed that WEP70 sensor output is 42uv per deg C. Connected MAX31856 Thermocouple to Digital Converter as K type and there is difference up to 30 deg C. If used as J type, 10 deg C difference . i want use existing circuit ofWSD81 with amplifier modification.

I disconnected op amp output from uC(PIC 16F833) and added 0-5V power supply. Then I measured changes voltage on uC input to temperature on display.

3.46V -> 450C
3.6V -> 430C
3.5V -> 420C
3.08V -> 350C
2.76V -> 300C
2.41V -> 250C
2.06V -> 200C
1.72V -> 150C
1.55 -> 125C
1.31 -> 100C

Temp vs Ohm for WEP70
https://drive.google.com/file/d/1rnwCHuXmn1hN-6EV6Uaop-YM5JTENz22/view?usp=sharing

WSD81 Schematic
https://drive.google.com/file/d/13FuGd4SxCQ4SbISW1Xo0eS6DBc5uD1Re/view?usp=sharing


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Author Topic: Weller WE1010 conversion for WSP80 handle (Read 3009 times)

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