====== Temperature Controller ======

The temperature controller used for regulating and stabilizing the temperature of the laser diode is a **Meerstetter TEC-1091-NTC56k-Pinheader** - [[groups:mg:meerstetter|IQWiki entry]]

===== Current Setup - Rack Mount=====

{{:groups:mg:meerstetter_temperature_controller_rack_mount_front_view.jpg?200|}} {{:groups:mg:meerstetter_temperature_controller_rack_mount_back_view.jpg?200|}} {{:groups:mg:meerstetter_temperature_controller_rack_mount_inside_view_3.jpg?300|}}  
{{:groups:mg:meerstetter_temperature_controller_rack_mount_inside_view_2.jpg?300|}}

  * **Switch**: controls connection between lab power supply and meerstetter
  * **Power LED**: on = power on, off = power off
  * **Status LED**: on = Temperature at setpoint, blinking = ramping to setpoint, off = power off or error
  * **USB**: connection to PC, see [[groups:mg:meerstetter|Meerstetter wiki entry]] for more information
  * **SUB D-9**: male connector, connects to [[groups:mg:laserdiode_mount|laser mount]]
  * **Tuchel socket**: connection to 5-24V @ 4A max

^ Socket  ^ Pin Name   ^ Connected To  ^ Explanation                       ^
| X1      | VIN        | XLR Plus      | connections for the power supply  |
| :::     | GND        | XLR GND       | :::                               |
| :::     | RES2       | LED Anode     | status LED                        |
| X2      | OUT +      | SUB D Pin 4   | TEC (+)                           |
| :::     | OUT -      | SUB D Pin 5   | TEC (-)                           |
| :::     | OBJ T° UA  | SUB D Pin 3   | NTC (-)                           |
| :::     | OBJ T° UB  | SUB D Pin 2   | NTC (+)                           |
| :::     | Shield     | SUB D Pin 9   | GND for shield of cable           |

The output of the Meerstetter is filtered as shown [[groups:mg:meerstetter#output_filter|here]].

For the configuration file of the Meerstetter refer to ''\\AFS\iqo.uni-hannover.de\projects\magnesium\Projekte\PTB Ultrastable laser\Laser at IQO\meerstetter rack einschub''

==== In loop stability ====

The Meerstetter stabilises the 1560 nm rio planex laser diode running at 123.5mA to the target temperature with a standard deviation of ca. 0.23 mK.

{{:groups:mg:meerstetter_rack-mount_in_loop_temperature_vs_time.png?400|}}{{:groups:mg:meerstetter_rack-mount_in_loop_temperature_stability.png?400|}}{{:groups:mg:meerstetter_rack-mount_in_loop_temperature_spectrum.png?400|}}

----

===== Old setup - in a Box=====

==== Overview ====

\\ {{:groups:mg:project_ptb-cavity:meerstetter.jpg?300|}} {{:groups:mg:project_ptb-cavity:meerstetter_2_.jpg?300|}}{{:groups:mg:project_ptb-cavity:meerstetterbox.jpg?200|}}\\

  * The **subD9 connector** is used to connect the Meerstetter to the Thorlabs mount for the laser diode and is configured specially for that purpose.
  * The **XLR socket** is used to connect the Meerstetter to a power supply.
  * The **Mini-USB socket** is used to connect the Meerstetter to a PC for configuration and data logging.

There is also a **status LED** connected to the Meerstetter. If the LED is constantly on, the wanted temperature is reached. A blinking LED means that the system is currently ramping towards the wanted temperature and if the led is off, there is an error or the Meerstetter is currently turned off.

==== Power Supply ====

The voltage range with which the Meerstetter can be powered is 5-24V DC, currently it is driven with **18V DC**. The power supply should be capable of delivering **4A**. Always use a **seperate power supply** for powering the Meerstetter.

==== Connections within the Case ====

=== Current Connections ===

Currently the connections are as shown in the table below:

^ Socket ^ Pin Name  ^ Connected To ^ Explanation                      ^
| X1     | VIN       | XLR Plus     | connections for the power supply |
| :::    | GND       | XLR GND      | :::                              |
| :::    | RES4      | LED Anode    | status LED                       |
| X2     | OUT +     | SUB D Pin 4  | TEC (+)                          |
| :::    | OUT -     | SUB D Pin 5  | TEC (-)                          |
| :::    | OBJ T° UA | SUB D Pin 3  | NTC (-)                          |
| :::    | OBJ T° UB | SUB D Pin 2  | NTC (+)                          |
| :::    | Shielding | SUB D Pin 9  | GND for shield of cable          |

{{:groups:mg:project_ptb-cavity:meerstetter_platine.png?400|}}\\

Different connectors were used for X1 and X2: \\ PSK for X1 \\ JAE for X2

<note warning>The SUB-D connector is wired up **especially** for the thorlabs mount. It is probably not compatible with other systems that use a SUB-D connector!</note>

=== Previous Connections ===

These were the **previous connections**. Differing connections were marked yellow.

^ Socket ^ Pin Name                     ^ Connected to  ^                                  ^ 
| X1     | VIN                          | XLR Plus      | connections for the power supply |
| :::    | GND                          | XLR GND       | :::                              |
| :::    | RES4                         | LED Anode     | status LED                       |
| X2     | OUT +                        | SUB D Pin 4   | TEC (+)                          |
| :::    | OUT -                        | SUB D Pin 5   | TEC (-)                          |
| :::    | <hi #fff200>OBJ T° IB</hi>   | SUB D Pin 3   | NTC (-)                          |
| :::    | <hi #fff200>OBJ T° IA</hi>   | SUB D Pin 2   | NTC (+)                          |
| :::    | <hi #fff200>OBJ T° UB</hi>   | SUB D Pin 9   | GND for shield of cable          |

==== Status LED ====

=== Current Setup ===

An extra LED is installed at the "RES4"-Pin at the X1 side with a 2,4 kΩ resistor and connected to GND.\\
{{:groups:mg:project_ptb-cavity:meerstetter-diode.jpg?400|}}

The Meerstetter is currently set up to control the LED like this:

^ LED          ^ Meaning                            ^
| constanly on | target temperature is reached      |
| blinking     | ramping towards target temperature |
| off          | error/Meerstetter is off           |