Yihua preheater 853A

[jpanhalt]

I got a Yihua 853A IR preheater for PCB's, not the AA or AAA versions.  It came with a display in °F, ugh.  No way to change that °C on the panel.  Yihua has been non-responsive.  It is remarkably stable based on an aluminum test block with TC pocket.

Is there an internal setting or jumper to change from °F to °C?

[PKTKS]

I am not familiar with this..

But isn't that just another REX 100 clone?

Paul

[jpanhalt]

It claims to have a PID controller.  Temperature is reasonably constant and changes with setting.*  The single A version has just one button on front.  The AA and AAA versions have two buttons and allow switching between °F and °C.  Unfortunately, the user's manual virtually ignores the single-A model.  However, listings and videos on the web all show the celsius model.  Ordered from Amazon, and there was no option to choose the temperature scale. I seems odd to me that changing from one version to the other would require reprogramming the MCU.   

*Apparently, the temperature being reported on the screen is at the ceramic radiator rather than where the PCB sits.  I measured temp with a small piece of aluminum flat sitting on the rails as a PCB would sit. A TC was embedded in the aluminum .
 
Picture attached.

[PKTKS]

nah this is not REX clones....

should be one of those common vanilla MCU based PID controllers...

AFAIK... if they are using STM you should  theoretically find some software hack for these..  they became very common  ...

but you would need to dismantle and fuss around the parts...
flashing the firmware would also need careful inspection.

Paul

[jpanhalt]

I was hoping it was just an internal jumper.  Unfortunately, none of the reviews I could find mentioned one, nor did it look like there was one in the teardowns.  They were all set for celsius too.  I'm one of those hybrid Americans.  I use fahrenheit for cooking and weather, and celsius for everything else.

The firmware for this preheater isn't on the Internet.  I guess I will just live with an arbitrary dial setting and rely on my measured temp in celsius.

John

[Krotow]

For these simple preheaters another method is to use some external thermometer like multimeter with temperature measuring support. And attach measuring probe to board. Real board temperature while heated will be different anyway. Write down temperature on preheater indicator and real temperature for future and use later.

[MR]

Also be sure that they have enough Watt, I have 2 which look the same but one is a lot more powerful.

I have the 853A it has 600Watt here  -- it takes a lot time to heat up. I don't remember the other one which I have because it's 8000km far away from me but it's significant more powerful and quicker.

[jpanhalt]

My Yihua branded 853A is labeled 450W on its data tag.  It gets plenty hot fast enough for me.