I am trying to build a FRED circuit using a 555 timer. Hoe do I tell which terminal ls 1 on the chip? It is a Radio Shack 555 timer built by Texas Instruments. I suspect that the ! termnal is onthe lower left end when reading Texas Instruments from the top of the chip, but I am not certain ( as thisis teh frist time I have tried anything like this).
Thanks for any help. My searches of the Internet were fruitless.
Google is your friend:
TI 555 specs
Edit: More here.
Instead of all the additional circuitry required for the 555 timer, you can get red 3mm LEDs with built-in flashers, and I have seen some advertised that are even smaller.
Pin 1 of most any IC is indicated by a dot or dimple, if not an outright mark like a small triangle or in some cases even the number 1.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for help solving the problem for me; the TI "top" view and the idea of the dimple, both confirm what I thought was the terminal #1; thanks stevert and rrinker; (I had tried to find a 3mm blinking led, could only locate a 5 mm in the local RS's.) Thanks again, guys.
MrMick I am trying to build a FRED circuit using a 555 timer. Hoe do I tell which terminal ls 1 on the chip? It is a Radio Shack 555 timer built by Texas Instruments. I suspect that the ! termnal is onthe lower left end when reading Texas Instruments from the top of the chip, but I am not certain ( as thisis teh frist time I have tried anything like this). Thanks for any help. My searches of the Internet were fruitless.
No problem here. No idea on how you did your search. I use this search engine which does not track you like Google does.
http://privatelee.qrobe.it/search/?q=555+circuit
Store the below link in Favorites. This guy has a lot of good info.
.http://home.cogeco.ca/~rpaisley4/LM555.html
http://home.cogeco.ca/~rpaisley4/CircuitIndex.html
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
ww.ebay.com/itm/20-HO-SCALE-RED-FLASHING-3MM-LEDS-WARNING-BEACONS-FREE-RESISTORS-FOR-12-V-/360449757806?pt=Model_RR_Trains&hash=item53ec7ad26e#ht_3733wt_1270 Try this its for 20 of them,Jim.
gondola1988 ww.ebay.com/itm/20-HO-SCALE-RED-FLASHING-3MM-LEDS-WARNING-BEACONS-FREE-RESISTORS-FOR-12-V-/360449757806?pt=Model_RR_Trains&hash=item53ec7ad26e#ht_3733wt_1270 Try this its for 20 of them,Jim.
What a mess. Now it is clickable.
http://tinyurl.com/83zmej6