![]() So, I decided to mount inside the clock a small LED light organ on the place of the digital clock display. I decided to use the clock only as radio, but to make it more interesting and attractive. The only functioning thing was the FM radio. The Si5351 is an extremely useful device, containing multiple clock generators with many versatile programming options that go well beyond its original purpose of providing a clock for digital. Were speaking at the edge of our knowledge so please bear with us but the short-term stability (Allan Deviation) is 810-12.From Wikipedia on Atomic Clocks. My attempt to repair the clock failed - it was not working. The Miniature Atomic Clock (MAC) from Microsemi uses a rubidium laser to output an extremely accurate clock. 5) In the clock was used a Chinese analog of the TA2003 AM/FM radio chip, but only the FM option was used, because it doesn't need ferrite antenna. 4) The flat cables used there were something exceptional - it was possible to split and strip them only by fingers. Apparently the MK6207N is a pin-compatible equivalent. This is Radio Shack part number 276-1755. This particular one is stamped Archer (Radio Shack's house brand), RS1755 with a date code of 7441 (1974). You can see a clock project using this chip by clicking here. 3) The PCB of the clock is done with extremely bad quality - it is impossibly practically to solder something on it without destroying the soldering pad or the corresponding track - they simply fall down from the PCB. You can see the datasheet for this chip here. First observations: 1) the PCB of the LED display was curved and the contacts to the between corresponding pads on the PCB and the LED display were bad 2) For the clock the LM8560 chip was used, which doesn't use a quartz generator, but is synchronized with the frequency of the AC power net (can be chosen 50 or 60 Hz) - that means bad time accuracy. I opened it to see what is the reason, breaking up the warranty. This lowest frequency clock may be a reset signal to a divider or a clock frequency used for 0-delay feedback in a PLL. A low frequency clock or DC signal carries with it information about the moment of a synchronization request. (something usual for products "Made in China") The clock was not going, some segments of the LED display were not working. low frequency clock rate with the timing information necessary to synchronize all clocks. The visual design is not bad, but the quality was terrible. I bought a radio clock produced by Scott.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |