tag:blogger.com,1999:blog-6615160292280278140.post8243106588247926975..comments2024-03-28T08:07:01.529-04:00Comments on Hands On - Make: Electronics: Chapter 3 - Exercise 15 Part 3James Floyd Kelly (Jim)http://www.blogger.com/profile/13876934942928389738noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-6615160292280278140.post-46730040320503980862010-12-26T10:38:39.680-05:002010-12-26T10:38:39.680-05:00After loosely breadboarding the 'alarm trigger...After loosely breadboarding the 'alarm trigger' half of this circuit, I transposed it to the bottom of the breadboard in the compressed layout recommended by the book, and, similar to your earlier problem with the locking relay, COULD ... NOT ... GET ... IT ... TO ... WORK! (Wouldn't wait for the magnetic switch signal to open) <br /><br />Stared at the circuit and the book drawings forever, reseated components, checked the online errata ... finally, it occurred to me to check the resistors. Sure enough, the new layout used one less resistor than the previous version, and I had grabbed the wrong resistor when I rebuilt the circuit.<br /><br />From now on, checking resistor values will be part of my troubleshooting path.Thrallhttps://www.blogger.com/profile/14857436453066969832noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-45696189657147602202010-02-06T02:10:19.027-05:002010-02-06T02:10:19.027-05:00Going off of what Nick said, this is actually a tr...Going off of what Nick said, this is actually a trick digital devices use to trick our eyes. By turning the LED on and off and a set rate, our Persistance of Vision makes it look as though the light is on at a particular brightness. The on/off cycle has to occur very quickly though, in terms of thousandths of a second...Aaronhttps://www.blogger.com/profile/03821060961655934831noreply@blogger.comtag:blogger.com,1999:blog-6615160292280278140.post-13394600941958382652010-02-05T16:52:35.006-05:002010-02-05T16:52:35.006-05:00The LED is pulsing, technically, but so fast that ...The LED is pulsing, technically, but so fast that you can't see. Remember from an earlier exercise that sound is created from electricity pulsing very fast. The slowest you'd be likely to hear would be pulsing about 20 times per second (20 Hz), but I'm guessing the circuit is set to cycle at several thousand times a second, so there's no way you'd see that with an LED.Unknownhttps://www.blogger.com/profile/07677164233375190996noreply@blogger.com