Repairing a camera with active cooling - Page 1
Forum section: electronics / repair

author: reinruby
author_rank: Newbie
timestamp: August 25, 2024, 01:39:31 pm
content: Hi there!Newbie here, but a long-time lurker. I finally decided to register an account.I have an old camera that I would like to repair. The sensor is cooled with a Peltier element, I have found the two pins that the element is connected to (the motherboard).The issue is rather simple and common on these cameras -- condensation.You can read more here:https://andor.oxinst.com/learning/view/article/what-are-camera-sensor-enclosures-and-why-do-they-matterBasically, the sensor is in a closed and sealed chamber. Over time, air gets in so when cooling is active, condensation occurs on the sensor window.I can attempt to pry it open so I can swap out the desiccants, however, it will likely damage the fragile flex cables and render the device useless. Tar glue is used.Instead of doing that, I am willing to compromise overall performance by removing the cooling altogether. I shorted the Peltier Element out and the camera worked fine, without condensation.I would like to permanently short it out by installing a jumper wire. I am wondering if it is safe to do so? The Peltier element is small (30x30mm) and I doubt it passes through much voltage and current. The camera itself uses a 60W power adaptor.Thank you for the help! Any advice is appreciated.

author: Phil1977
author_rank: Frequent Contributor
timestamp: August 25, 2024, 01:55:25 pm
content: Hi, welcome to the forum!In most cases Peltier drivers are current controlled, so shorting it out may be no problem.But just in case the controller is not fit for a short circuit: Why don't you just cut the connection of the Peltier element? If no current is flowing no heat can be dissipated, neither in the Peltier assembly nor in its driver.

author: CaptDon
author_rank: Super Contributor
timestamp: August 25, 2024, 11:27:13 pm
content: Shorting out the element to disable it is like leaving your running car in gear and chaining it to a pole so it won't go anywhere. Why not create an open circuit instead of a short?

author: perieanuo
author_rank: Frequent Contributor
timestamp: August 26, 2024, 12:04:36 pm
content: Quote from: Phil1977 on August 25, 2024, 01:55:25 pmhi, it's not a rule, i had projects with peltier used for heat/cool with chopped ac voltagei don't subscribe to peltier pins shorting, current control can be checked simply with some ampermeter or 10 minutes reverse engineering on schematic. if it's current regulation, i bet current regulator can be simply eliminated and that's it

author: reinruby
author_rank: Newbie
timestamp: August 27, 2024, 03:25:29 am
content: Quote from: Phil1977 on August 25, 2024, 01:55:25 pmQuote from: CaptDon on August 25, 2024, 11:27:13 pmThat is possible but extremely risky. The sensor board is mated to the Peltier element and completely covers it. The flex cables must be lifted to access the pins to snap one of them.Desoldering is impossible because of this as well. Additionally, the pins are very close to the sensor itself. I no longer trust my hands to be stable enough after a biking accident.Thank you for the information, I will just install a jumper wire.The Peltier element is marked 6D 16D08, I could not find any information.(I have another that failed so I pulled it apart completely.)Quote from: perieanuo on August 26, 2024, 12:04:36 pmThe camera is beyond complicated but I could try and trace the Peltier element to somewhere else and create an open circuit.Thanks for the help.