Differences

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--- d2:laser_controller [2021/02/26 22:52] – Michael Radunsky
+++ d2:laser_controller [2024/03/27 15:33] (current) – Captilizing Rth_RTN to match table. Thomas Bersano
@@ Line 28: / Line 28: @@
 As with __any__ diode laser and controller, improper usage can cause irreparable damage to the diode.
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 <WRAP center round important 60%>
 If you are considering using an Uninterruptible Power Supply (UPS) to guarantee operation of your Vescent products through a brown out or black out, great care should be taken in choosing the model.  Lower cost models tend to produce modified square wave voltage profiles.  The high-frequency components of such a voltage profile may interact poorly with the D2-005 (and down-stream active Vescent modules).  If you do choose to use a UPS, select a model that will provide a sine wave voltage profile without higher harmonic components to avoid potential damage to your high-value equipment.
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+<WRAP center round important 60%>
+Both temp control loops can be toggled with a board-level switch located under the PID tuning switches. If you are experiencing problems with either of your temp loops, please toggle this switch off and then on again, as it's possible for the switch to get bumped into an intermittent position where it looks on, but is off. The most common symptom of this issue is that the faulty temp loop's front panel LED will turn red, but this does not always happen.
+</WRAP>
 ==== Purchase Includes: ====
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 T1 is also set at the factory and should not require further adjustment.  However, the T1 trimpot can be accessed by removing the right panel from the enclosure.  Note: Before attempting to set the set point temperature, you must connect a thermal plant to the D2-105.  If you do not have a plant attached to the temperature loop, the set point range will appear to be limited to less than ~12°C.
+<WRAP center round important 60%>
+Both temp control loops can be toggled with a board-level switch located under the PID tuning switches (see <imgref standby_switch>). If you are experiencing problems with either of your temp loops, please toggle this switch off and then on again, as it's possible for the switch to get bumped into an intermittent position where it looks on, but is off. The most common symptom of this issue is that the faulty temp loop's front panel LED will turn red, but this does not always happen.
+</WRAP>
+<imgcaption standby_switch|The location of the control switches for T1 and T2.>{{ :d2:d2-105:standby_switch_loation.jpg?600 |}}</imgcaption>
 **Temp Lock (Dual position switch)**
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 The temperature servo input is summed to the T2 temperature set point signal and can be used to make electronic perturbations to the laser diode temperature.  The Temp Servo Input, has two settings: "Low" and "High" gain. The default settings is "Low" but can be changed by a switch accessible on the right side panel. See <imgref VPN00267>.
 <WRAP center round box 570px><imgcaption VPN00267|Temp control board with T2 Temp Servo Input gain switch circled>[{{ d2:d2-105:vpn00267.gif?nolink&550 | filler text }}]</imgcaption></WRAP>
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 **Laser Temp Output (8-pin connector)**
-An 8-pin Hirose connector (see <tabref TECconnectortable> for identity of connectors) carries the signals for the temperature control of the Laser module.  The wiring diagrams are shown in <tabref TEC_connector_pinout> below, where 1 (2) refer to stage 1 (2) temperature control, which stabilizes the Laser Housing (Laser Diode). Rth and Rth_Rtn are the two ends of a 10 kΩ [[http://www.analogtechnologies.com/ath10kr8.html|Analog Technologies ATH10KR8 Thermistor]].
+An 8-pin Hirose connector (see <tabref TECconnectortable> for identity of connectors) carries the signals for the temperature control of the Laser module.  The wiring diagrams are shown in <tabref TEC_connector_pinout> below, where 1 (2) refer to stage 1 (2) temperature control, which stabilizes the Laser Housing (Laser Diode). Rth and Rth_RTN are the two ends of a 10 kΩ [[http://www.analogtechnologies.com/ath10kr8.html|Analog Technologies ATH10KR8 Thermistor]].
 <WRAP round center box 230px><tabcaption TEC_connector_pinout| TEC connector pin out>
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 {{ :d2:d-sub_power_pinout.jpg?nolink&150 |}}
+While it is infrequent, the D2-005 power supply may occasionally radiate noise from the side of its chassis onto nearby electronics. This only occurs in some system configurations, and will appear as a signal at the frequency of your mains electricity (typically either 50 Hz or 60 Hz). This noise can easily be removed by moving the D2-005 at least 18 inches (45cm) away from other electronics, rotating it 90° such that the sides of the D2-005 face away, or by moving the entire power supply to a different shelf. To accommodate this, all D2-005's are shipped with a 5' DB9 cable as of January 1, 2022.
 **Laser Enable**
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 **Remote Interlock**
-The remote interlock can be used to disable the laser diode output via an interlock control.  When this input is shorted the laser diode output is ON.  When the input is open the diode output is OFF.  If not used, leave a shorting cap over this BNC. Once the interlock has been tripped, the laser will stay off until it is manually reset with the front panel switch.
+The remote interlock can be used to disable the laser diode output via an interlock control.  When this input is shorted the laser diode output is ON.  When the input is open the diode output is OFF.  If not used, leave a 50Ω BNC terminator over this BNC. Once the interlock has been tripped, the laser will stay off until it is manually reset with the front panel switch.
 **Setpoint In**
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   - Measure the resistance across GND5 and probe point GAIN2. Set this resistance to between 1.2 kΩ and 1.4 kΩ by adjusting trimpot PROPGAIN2.
-<WRAP center round box 570px><imgcaption factory_set_post6987|Factory settings of T2 (left) and T1 (right) poles for units with S/N 2675 or higher (PCBs with S/N 6987 and higher)>[{{ :d2:d2-105:temp_loop_post_sn_6987_w_text.png?nolink&550 | filler text }}]</imgcaption></WRAP>
+<WRAP center round box 570px><imgcaption factory_set_post6987|Factory settings of T2 (left) and T1 (right) poles for units with S/N 2675 or higher (PCBs with S/N 6987 and higher)>[{{ :d2:d2-105:Modern_Corners.jpg?nolink&550 | filler text }}]</imgcaption></WRAP>
 <WRAP center round box 60%><tabcaption factory_set2_post6987|Factory settings of T2 Proportional poles (first DIP switch in figure) and T2 Differential poles (second DIP switch in figure) for units with S/N 2675 or higher (PCBs with S/N 6987 and higher)>
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 //NOTE: Depending on the thermal design, nested temperature loops can fight each other, causing oscillations and instability. If you observe this, you will need to reduce the gain and/or increase the time-constants on the slower stage. //
-===Tuning Temperature Loop for Photodigm Mercury Lasers===
+===Tuning Temperature Loop for Photodigm Mercury Lasers if you have an older D2-105===
+If you have a D2-105 with S/N 2674 or lower (PCBs with S/N 6986 and lower), then you may still be able to tune the parameters of the loop to stably control the temperature of the TOSA by following the protocol below:
 If you are using the D2-105 laser controller to drive a Photodigm Mercury laser in a TOSA package, the following may be helpful as a starting point for setting the thermal control loop parameters.((Courtesy of [[http://www.photodigm.com|Photodigm]]))  Refer to <imgref side_adjustb>.