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I am doing a system design presently which involves an OEM optical amplifier module (Dimensions: 220 x 250 x 60mm). It has got an operating temperature range from 0 deg. to 40 deg.C. However, my system is supposed to operate all the way from 60 deg.C down to -30 deg.C. The support personnel for the component informed that it can be ruggedized to make it operate in the required temperature range. Does anyone know how the ruggedization can be done?

Update
After testing the module, we have found that it can operate till 60 deg. C without any issues. Hence cooling mechanism at high temperatures is not required. All I need is a heating mechanism which can heat up the module when it goes to negative temperatures. Which type of heater will be best suited for this application? My system has a 28V DC input and I will have to heat up a face with 220mm x 250mm area.

Avin
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  • Speculation but they might just mean you could design a heating / cooling system to keep it within those limits. – PeterJ Dec 12 '13 at 11:46
  • @PeterJ I was also thinking about doing the same thing. But should I be designing the heating/cooling systems myself or will I get any pre-built ones? – Avin Dec 12 '13 at 12:01
  • Never had to do anything similar myself but I'm not aware of any pre-built units. It might be worth adding some more details on the overall size / environment etc though so someone might be able to suggest what peltier and other solutions might be suitable. If it's a single chip I believe some small peltier devices are available that might do the job combined with a fan and a control system. – PeterJ Dec 12 '13 at 12:10
  • Well if the "support personnel" said it can be ruggedized then why don't you just ask them? – lyndon Dec 12 '13 at 12:45
  • It is not a chip, it is a module of dimensions 220 x 250 x 60mm. The system size has not been fixed as the design for the ruggedization element is yet to be understood. Anyways, I'll add the dimensions also in the above question. I did come across some Peltier solutions while googling, but I believe they can work only for 1 purpose - either heating or cooling. Can a single solution work for both heating and cooling? – Avin Dec 12 '13 at 12:48
  • @lyndon The support personnel told that it can be ruggedized but they didn't have the technology to get it done or the knowhow to share it with me. – Avin Dec 12 '13 at 12:52
  • Yes, a Peltier device can be used to regulate the temperature by heating or cooling, as required. It may be practical if the device does not dissipate too much power. Note that testing a single device over an extended temperature range is probably not sufficient to guarantee it will work reliably, let alone future similar devices. – Spehro Pefhany Feb 10 '14 at 13:16
  • @SpehroPefhany Peltier was my choice #1. However, the power dissipation for this device is around 70-100W. And provided that my area to be heated is also more, I am doubtful about the effectiveness of the scheme. – Avin Feb 10 '14 at 13:34
  • @Avin I agree there is great doubt that can be made to work practically, as Peltier devices are notoriously inefficient. – Spehro Pefhany Feb 10 '14 at 13:40
  • Is it possible to use simple resistor heating to achieve this? I have a 28V supply input from which I can presently spare upto 4A. Can I use chassis mount resistors to achieve the required temperature change? – Avin Feb 11 '14 at 07:23
  • So this module is specified for 0 to 40C. How many have you tested when you determined that it can operate to 60C without an issue? How many of these are you planning on building? If you're building one or two, you're probably OK. If you're planning on building hundreds, I'd be really worried about that. – rfdave Apr 17 '14 at 00:34
  • @Dave the quantity is less.. maybe < 10. So I guess it should be ok, right? – Avin Apr 17 '14 at 05:24
  • At 10 units, you've got much less risk than building hundreds. You're still using parts out of spec, so you might want to consider doing a burn in of each one at +60C before you ship, just in case. Have a couple of spare modules, also.

    If this is a commercial venture, make sure that others in your organization know what's going on, as this is the kind of thing that makes management unhappy if they find out after things ship.

     – rfdave Apr 17 '14 at 11:00

1 Answers1

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We had to warm up an enclosure for this very reason. We ended up using a heater such as this one. There are many of these; try searching for "Enclosure Heaters". Most 24VDC heaters will run on 28V; make sure you check the spec sheets.

If the heater doesn't come with a thermostat, this one is good and relatively inexpensive. Set its trip point down to near-freezing.

As far as determining how much wattage you need, it depends on the area of exposed surface, the lowest ambient temp it may see, and the material of the enclosure. I believe that there are online calculators for this, although in my company the mechanical engineers figured out that part :)

Good luck!

bitsmack
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