After an hour of making a timer with a relay circuit from one of Forest Mims books, The circuit wasnt working, so after about 5 minutes of troubleshooting I produced the magic smoke. The 555 went up like a smoke bomb. Oh well, back to the drawing board.
the magic smoke is the worst sign of electronics, especially the smell. just go over the circuit, check it, if it's good, put another 555 in and try again. if it still doesn't work after that, the circuit is wrong
the magic smoke is the worst sign of electronics, especially the smell. just go over the circuit, check it, if it's good, put another 555 in and try again. if it still doesn't work after that, the circuit is wrong
I had a circuit with a 555 on it from a heap of electronics I bought off a bloke and for some silly reason he used the red wire for negative and green wire for positive. Yes you guessed it I hooked it up to a 12 volt battery and the top of the 555 hit the roof of the shed.
I got the smell also, I thought I installed one of the diodes backwards but I checked them with my meter and they werent. :?: I only applied 12v, Not sure what happend.
Yea, it was new and i tried a couple different ones. Id like to make boards for these 555 projects. I am tired of using perf board because bigger projects (not this project) get complicated.
I connected a simple LM386 when I was first starting electronics (about 3rd grade) wrong, and after a while the tone of the speaker started to fall, and then the caps blew (6.3v rating, had no Idea about voltage ratings), and then the LM386 started melting the insulation off a wire that was making contact with a nearby wire (wire made contact on the casing), then it went...
BOOM!
Loud too scared the crap out of me and my mom and dad!
well if it's working, it usually doesn't smell bad. but then again, it's what its made of that makes it stink so i guess there is chemistry involved then
I got the smell also, I thought I installed one of the diodes backwards but I checked them with my meter and they werent. :?: I only applied 12v, Not sure what happend.
Can you post a schematic or a picture? I did a simple 555 astable (5-10 Hz, 20% duty cycle) earlier today. Had a diode in backward (1n914). Got it to flash an LED, so hooked up a part I scrounged from an old, huge IBM printer. Its one of many print hammers, about the same as a relay. Don't have any specs, smoke wouldn't be a big deal. The LED stayed on, the coil didn't pull the hammer. Figured not enough current, maybe the 555 voltage drop... So put a cap in parallel with the LED and hammer, works. No smoke, not even warm. Only using 6 volts though.
I have no way of posting the schematic, but its on page 9 of Forrest Mimms 555 Timer IC circuits.
Whats funny or scary, depending on how you look at it is, I still have some of the same books I had when I was 17, Im 36 now, and some of them I have re-purchased after getting back into electronics........
]I have no way of posting the schematic[/B], but its on page 9 of Forrest Mimms 555 Timer IC circuits.
Whats funny or scary, depending on how you look at it is, I still have some of the same books I had when I was 17, Im 36 now, and some of them I have re-purchased after getting back into electronics........