| Products > Test Equipment |
| SPD3303X Hiccup |
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| mawyatt:
--- Quote from: tautech on August 20, 2024, 09:22:59 pm --- --- Quote from: mawyatt on August 20, 2024, 02:59:36 pm ---Here's a thermal image of the Bridge Rectifier with heatsink and area around, things are very warm including the caps. However the one cap isn't bulging, it's just the angle of the image. The Max Temp is the T0-92 device (Regulator?). After about 4~5 days, we haven't experienced a reset. --- End quote --- :-+ --- Quote ---Could someone with a new 3303 post a thermal image of this area to compare temperatures temperature distribution? --- End quote --- Rectifier stage has been reworked now Mike: The only reason we've had to lift the covers on these PSU's are for bridge failures yet early units gave zero problems. --- End quote --- Certainly a bigger bridge rectifier!! Where is the TO-92 component located? A good thermal image of this area would be useful to see how things are distributed wrt version we have. Best, |
| tautech:
--- Quote from: mawyatt on August 20, 2024, 10:49:50 pm ---Certainly a bigger bridge rectifier!! Where is the TO-92 component located? --- End quote --- Sorry Mike, dunno and as old HW is a straightforward fix we aren't stocking any new PCB's to get an image from. |
| TheDefpom:
Reworked but still got caps right next to something that gets hot... This is a pet peeve of mine, I come across it all of the time, designers putting capacitors right next to heat sinks or things that get hot, even moving the caps 10mm further away would make such a huge difference ! WHY do people design things so it heats the caps up, this makes them fail much sooner... so instead of lasting 20 years it might last 10. |
| tautech:
--- Quote from: TheDefpom on August 22, 2024, 12:00:56 am ---Reworked but still got caps right next to something that gets hot... --- End quote --- But does it ? Until someone places a TC on the new bridge or does an IR measurement we just don't know.. |
| Sorama:
--- Quote from: thm_w on August 20, 2024, 09:44:21 pm --- --- Quote from: Sorama on August 20, 2024, 05:40:55 pm ---a quantitative measurement using IR won't be possible. First you would have to determine the emission factor, secondly you're measuring a metal (the heatsink) which has a low emission and therefore hard to measure by IR. A (qualitative) measurement with the same IR camera from the same angle would give a representative impression of the heat that is generated over there. --- End quote --- Have you ever actually used an IR camera? Black anodized aluminum has an emissivity of 0.82-0.86. Which is fine. Even if it wasn't you can see the plastic package right underneath (would be around 0.9). https://www.design1st.com/Design-Resource-Library/engineering_data/ThermalEmissivityValues.pdf --- End quote --- As a L2 Thermographer I use Flir IR cameras all day long. So yes. Emission of 0,8x is rather low, so measured temperature is pretty off. TS wants to see the impact of the heat on the other components, but they do have very different emission factors (like the blinking alu cover of a capacitor). I bet emission factor of the used camera was not even set to what it should be. So even if it gives ‘nice’ ir pictures, they certainly won’t tell much (actually nothing at all) about the individual temperature of components. |
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