开云体育

In light of links I just posted with devices/ items most likely of Chinese origin, I always tell everyone to be careful of anything obtained from there.?? Although none of the aforementioned devices have caused any issues presently, I did have a situation with so-called "30 amp" lamp dimmers last fall. I was trying to use one to control a simple load not using more than 5 amps at 12 VDC.? Upon first dimmer's arrival and implementation, I noticed that it ran quite cool to the touch and no initial issues.? However, right where I am sitting now and the dimmer about 3 feet away, one day I noticed it started smoking and I ran to it as it burst into flame.? I decided to try a replacement.? The initial replacement ran far warmer than the original, even though the same type, so I placed it close to me as it ran.? Within minutes, it started smoking too.? Then the final dimmer, this time placed on a completely separate system drawing fewer amps.? Within a week, it too failed although not in grand fashion like the other two.? It was obvious to me that there was something wrong with the circuit from the start.? Since these were all purchased from the same seller and within the return period, I demanded refunds for all.? At first the seller resisted and I finally got eBay involved and it was resolved.? The seller wanted them back after I sent him images of the burned up ones.? I said no problem if he paid for shipping, which he didn't want to do. After the refund instituted by Ebay, I tossed them all in the trash.? Be wary of any Chinese electronic devices, always test and double test items upon arrival.

Just some food for thought.? On the other hand, I ordered and am still using one of those "30 dB" HF preamp boards for like $10. It's doing a good job at HF if/ when I use it, which isn't that often really.? I originally got it to help boost frequency counter sensitivity, which it does well.

Jon