Cooling and power supply
Regulated thermoelectric cooling is capable to cool the CMOS sensor up to 45 °C below ambient temperature. The Peltier hot side is cooled by fans. The sensor temperature is regulated with ±0.1 °C precision. High temperature drop and precision regulation ensure very low dark current for long exposures and allow proper image calibration.
The airflow is slightly different between C5A and C5S models.
- C5A camera air intake is located on the top side of the camera head; hot air output vents are on the camera back side.
- C5S camera air intake is on the camera bottom and output vents are on top.
The cooling performance depends on the environmental conditions and also on the power supply. If the power supply voltage drops below 12 V, the maximum temperature drop is lower.
| Sensor cooling | Thermoelectric (Peltier modules) |
| Cooling ΔT | 45 °C below ambient regulated |
| 48 °C below ambient maximum | |
| Regulation precision | 0.1 °C |
| Hot side cooling | Forced air flow |
Chip cooling specifications
The cooling performance depends on the environmental conditions and also on the power supply. If the power supply voltage drops below 12 V, the maximum temperature drop is lower.
| Sensor cooling | Thermoelectric (Peltier modules) |
| Cooling ΔT | 45 °C below ambient regulated |
| 48 °C below ambient maximum | |
| Regulation precision | 0.1 °C |
| Hot side cooling | Forced air flow |
Chip cooling specifications
C5A-100M cameras reaching -45°C below ambient sensor temperature
| Remark:
Maximum temperature difference between the sensor and ambient air may be reached when the cooling runs at 100% power. However, temperature cannot be regulated in such case, camera has no room for keeping the sensor temperature when the ambient temperature rises. Typical temperature drop can be achieved with cooling running at approx. 90% power, which provides enough room for regulation. |
Overheating protection
The C5 cameras are equipped with an overheating protection in their firmware. This protection is designed to prevent the Peltier hot side to reach temperatures above ~50°C sensor cooling is turned off to stop heat generation by the hot side of the Peltier TEC modules.
| Remark:
Please note the overheating protection uses immediate temperature measurement, while the value of camera temperature, presented to the user, shows temperature averaged over a longer period. So, overheating protection may be engaged even before the displayed camera temperature reaches 50°C. |
Turning the overheating protection on results in a drop in cooling power, a decrease in the internal temperature of the camera and an increase in the temperature of the sensor. However, when the camera cools its internals down below the limit, cooling is turned on again. If the environment temperature is still high, camera internal temperature rises above the limit an overheating protection becomes active again.
| Remark:
Please note this behavior may be mistaken for camera malfunction, but it is only necessary to operate the camera in the colder environment or to lower the desired sensor delta T to lower the amount of heat generated by the Peltier modules. The overheating protection is virtually never activated during real observing sessions, even if the environment temperature at night reaches 25°C or more, because camera internal temperature does not reach the limit. But if the camera is operated indoors in hot climate, overheating protection may be activated. |
Power supply
The 12 V DC power supply enables camera operation from arbitrary power source including batteries, wall adapters etc. Universal 100-240 V AC/50-60 Hz, 120 W “brick” adapter is supplied with the camera. Although the camera power consumption does not exceed 60 W, the 120 W power supply ensures noise-free operation.
| Remark:
The power connector on the C5 camera head differs from the 5.5/2.5 mm power plug, used on other Cx camera lines, because of the higher power draw of the C5 cameras. New power connector also ensures safer connection. |
| Camera power supply | 12 V DC |
| Camera power consumption | <9 W without cooling |
| 60 W maximum cooling | |
| Power connector | 4-pin plug |
| Adapter input voltage | 100-240 V AC/50-60 Hz |
| Adapter output voltage | 12 V DC/10 A |
| Adapter maximum power | 120 W |
Power supply specification
|
Remark: Power consumption is measured on the 12 V DC side. Power consumption on the AC side of the supplied AC/DC power brick is higher. The camera contains its own power supplies inside, so it can be powered by unregulated 12 V DC power source — the input voltage can be anywhere between 10 and 14 V. However, some parameters (like cooling efficiency) can degrade if the supply drops below 12 V. C5 camera measures its input voltage and provides it to the control software. Input voltage is displayed in the Cooling tab of the Imaging Camera control tool in the SIPS program. This feature is important especially if you power the camera from batteries. |
12 V DC/10 A power supply adapter for C5 camera
Mechanical Specifications
Compact and robust camera head measures only 154 × 154 × 76 mm (approx. 6 × 6 × 3 inches).
The head is CNC-machined from high-quality aluminum and black anodized. The head itself contains USB-B (device) connector and 4-pin 12 V DC power plug, no other parts, except a “brick” power supply, are necessary. Another connector on the camera head allows control of optional external filter wheel.
Integrated mechanical shutter of the C5A models allows automatic dark frame exposures, which are necessary for unattended, robotic setups.
| Internal mechanical shutter | C5A yes, blade shutter |
| C5S no | |
| Camera head dimensions | 154 mm × 154 mm × 76 mm |
| Camera head weight | 1.9 kg (without filter wheel) |
| 2.8 kg (with the “XL” external filter wheel) |
Mechanical specification
C5A camera head front view
C5A camera head interface for filter wheel or tiltable adapter base
Filter wheels or tiltable adapter base are attached to the camera head using six M3 screws around the 70 mm diameter ring.
C5A camera with M85 × 1 threaded adapter
C5A camera head with M85 × 1
The stated back focal distances (BFD) include corrections for all optical elements in the light path (cold chamber optical window, sensor cover glass, ...), fixed in the camera body. So, stated values are not mechanical, but optical back focal distances. However, no corrections for filters are included, as the thicknesses of various filters are very different.
|
Hint: Note the M85 × 1 adapter is also equipped with eight M3 threaded holes arranged around the 91 mm diameter circle. These threaded holes provide alternative mean of camera attachment to the optical system. |
C5A camera with M68 × 1 threaded adapter
C5A camera head with M85 × 1
C5A camera with C5-OAG with M85 × 1 thread
C5-OAG is designed to be used with the XL-sized External filter wheels only.
