Simple and Mighty

Our SimpleFlow-II Reflow Oven Controller with Dual Thermocouples.


Robust and Intelligent

We applied over dozens of usage scenario's and strengthen it with hundreds of lines of code.

From enforcing the WDT, to enacting rules to detect and adaptively compensate for disturbances.  It is now quite robust and quite smart.


PID Temperature Control

The PID algorithm has been greatly reworked in velocity form.  A great steady temperature control is very much achievable.

Check out the temperature curve in our reflow oven mod.  This is from 19~100 degC.

USB Serial Data Output

Outputs serial data via FTDI FT231X USB UART for thermal profile analysis and for refining the thermal profile.

We like FTDI for its great SW support and HW stability.

Mini-Jack Connectors

The right PCC-SMP mini jacks, just Plug and Play.  No need to mess with the thermocouple wires.

This also ensures proper signal delivery.


Two Is Better Than One

The SimpleFlow-II has Two Thermocouples (MAX31856) onboard.

Monitor the actual PCB/component temperature profile against the oven temperature profile.

Remember, it's the actual PCB/component temperature that really matters, not the oven; and chances are they are not equal.


Compensate Reflow Profile In-Flight

With only seconds left, you sense the Reflow Profile needing more time in the phase to yield success.  What would you do?

Compensate the profile while halfway into the Soak/Reflow Phase.



Bake / Curing / Drying

Yes, you've seen those MSL warning labels.  You may have ignored them for various reasons (as we once did).

Many IC's, LED's, connectors are moisture sensitive and need to be baked before SMT process.  Bake before use will reduce unexpected field failures.

Heat treatment is also an important phase for other works such as powder coating, porcelain clay paint, pre-process for electro-plating and many more; not just SMT.

PS...Yes, do bake before using that PCB or that QFN chip stored in the drawers 3-months ago.


Enhanced Servo PWM Output

We gave the Servo Output a separate power path to ensure system stability; and added reverse EMF protection.

The stability boost is good.


Want More Thermocouple Inputs?

OK, so Two MAX31856 thermocouples are not enough.  How about the option to add four more MAX31856?


The SimpleFlow Reflow Oven Controller was created using some of the best parts and with the Arduino Platform.  If you'd like to utilize this controller board for something else, you are very welcome to.  We can supply the base display libraries for your tinkering.

Features Descriptions
Power Input 5VDC (with reverse polarity protection)
Control Method PID
Lead-Free Reflow Yes
Reflow Profile Type Soak-Ramp Profile
Bake Function Yes, adjustable target temperatures from 30-250 degC with a Pre-Heat Phase
Bake Duration From 15mins to 10 days
Self Learning Yes
In-Flight Adjust Yes
Buzzer Alerts Yes
Data Link USB Serial Link via FTDI FT231X
Thermocouple IC 2 x MAX31856 (with enhanced noise immunity and expandable to 6)
Cold-Junction Error: +/- 0.7°C (-20-+85 degC)
Gain Error: -0.13 / +0.12 (-200°C to +1372 degC)
Built-In Linearity Correction
Thermocouple Connector PCC-SMP compatible mini jacks
Outputs 4 x MOSFET output (200mA; open drain);
1 x Servo PWM output (with reverse EMF protect and separate power path)
Output Terminal Block Eurostyle (Rising Cage Clamp)
Output Status Display Yes, LED on each output
Supported Output Types Top/Bottom Elements
Additional Heat Elements
Internal Convection Fan
External Cooling Fan