I have made one (circuit)and I have seen the page
Model Railroad & Misc. Electronics http://home.cogeco.ca/~rpaisley4/CircuitIndex.html
but what are some of your favorite IC555 circuits
I'm not the best at electronics.
but I can solder a few wires
also some simple flashing circuits have quite a few parts and this little timer seems to save a ton of parts
and that saves me money
thanks for some help
Pin 1 Ground The ground (or common) pin is connected to the 0v rail - commonly called the negative rail or EARTH rail. Pin 2 Trigger This pin connects to the lower comparator and is used to set the control flip flop. When it is taken LOW, it causes the output to go HIGH. This is the beginning of the timing sequence for a monostable operation. Triggering is accomplished by taking the pin below 1/3 of rail voltage - in digital terms, this is called a LOW. The action of the trigger input is level-sensitive, allowing slow rate-of-change waveforms, (as well as pulses), to be used as trigger sources. The trigger pulse must be of shorter duration than the time interval determined by external R and C. If this pin is held low for a longer period of time, the output will remain high until the trigger input is high again.If the trigger input remains lower than 1/3 rail voltage for longer than the timing cycle, the timer will re-trigger upon termination of the first output pulse. When the timer is used in monostable mode with trigger pulses longer than the output pulse, the trigger duration must be shortened by external circuitry.The minimum pulse-width for reliable triggering is about 10uS.Pin 3 Output The output of the 555 comes from a high-current totem-pole stage. This provides both sinking and sourcing current. The high-state output voltage is about 1.7 volts less than the supply. At 15 volt supply, the chip can sink 200mA with an output-low voltage level of 2 volts. High-state level is 13.3 volts. Both rise and fall times of the output waveform are quite fast, typical switching being 100nS.To make the output HIGH, the TRIGGER PIN (pin 2) is momentarily taken from a HIGH to a LOW. This causes the output to go HIGH. This is the only way the output can be made to go high. The output can be returned to a LOW by making the THRESHOLD PIN (Pin 6) go from a LOW to a HIGH.The output can also be made to go LOW by taking the RESET PIN to a LOW state.Pin 4 Reset This pin is used to make the OUTPUT PIN (Pin 3) LOW. The reset pin must go below 0.7 volt and it needs 0.1mA to reset the chip. The RESET PIN is an overriding function. It will force the OUTPUT PIN to go LOW regardless of the state of the TRIGGER PIN (Pin 2). It can be used to terminate an output pulse prematurely, to gate oscillations from "on" to "off." The pin is active when a voltage level between 0v and 0.4 volt is applied to it. When not used, it is recommended that the RESET PIN be tied to the positive rail to avoid the possibility of false resetting.Pin 5 Control Voltage This pin allows direct access to the 2/3 voltage-divider point. This is the reference level for the upper comparator. When the 555 timer is used in a voltage-controlled mode, the voltage-controlled operation ranges from about 1 volt below rail-voltage to 2 volts above ground (0v). Voltages can be safely applied outside these limits, but they should be confined to between 0v and rail voltage. By applying a voltage to this pin, it is possible to vary the timing of the chip independently of the RC network. The control voltage may be varied from 45 to 90% of the Vcc in the monostable mode, making it possible to control the width of the output pulse independently of RC. When used in the astable mode, the control voltage can be varied from 1.7v to the full Vcc. Varying the voltage in the astable mode will produce a frequency modulated (FM) output.If the control-voltage pin is not used, it should be bypassed to ground, with a 10n capacitor to prevent noise entering the chip. Pin 6 Threshold Pin 6 is one input to the upper comparator (the other is pin 5). It makes the OUTPUT PIN go LOW. To make the output go LOW, the Threshold pin is taken from a LOW to a level above 2/3 of rail voltage. This pin is level-sensitive, allowing slow rate-of-change waveforms to be detected.A dc current, termed the threshold current, must also flow into this pin from the external circuit. This current is typically 0.1µA, and will determine the upper limit of total resistance allowable from pin 6 to rail. For 5v operation the resistance is 16M. For 15v operation, the maximum resistance is 20M.Pin 7 Discharge This pin is connected to the open collector of an NPN transistor. The emitter goes to ground. When the transistor is turned "on,'" pin 7 is effectively shorted to ground. The timing capacitor is connected between pin 7 and ground and is discharged when the transistor turns "on". The conduction state of this transistor is identical in timing to that of the output stage. It is "on" (low resistance to ground) when the output is LOW and "off" (high resistance to ground) when the output is HIGH.Maximum collector current is internally limited by design, so that any size capacitor can be used without damage to the chip. In certain applications, this open collector output can be used as an auxiliary output terminal, with current-sinking capability similar to the OUTPUT (pin 3).Pin 8 Rail This pin (also referred to as Vcc) is the positive supply voltage pin for the 555. Supply-voltage operating range is +4.5 volts to +16 volts. The chip will operate over this voltage range without change in timing period. The only change is the output drive capability, which increases in current as the supply voltage is increased.
don't be shy
no job is too small, you may spark an idea!!
K
This is the exact reason why I purchase and use pre-made circuits. My time is very valuble to me and sitting at a desk for hours upon hours soldering electronic components together with a very high risk chance of them not working because solder slag drifted across a terminal or a wrong or misread connection got soldered to the wrong terminal is why I don't make my own circuits. I was there one time and found out real fast that homemade circuits are not the way to go. I can get train detection circuits and flasher circuits from reputable electronic suppliers that are just about guaranteed to work with minimal wiring and they are cheap enough to keep me out of the poor house.
The only circuit that i'll build from scratch is one that steps down 12 volts to 1.5 volts for my 1.5 volt incandecent light bulbs. If i screw that one up i'm only out 2 capacitors, 2 resistors, a voltage regulator and a bridge diode total price, about 4 bucks...chuck
I know it sounds funny, but when I put all those little parts together, I just felt a feeling of an accomplishment. silly but I know there are a few circuits that the 555 fits, I did see a 12v to 5v with this little chip. I know some people used them on there layout, I see a few flashing circuits that use a ton of parts. and this 555 timer can do the same job with only 3 or 4 parts.
I just ordered 50 of the 555 timer chips and hope to see a few people jump in here with some new circuits
Budliner wrote: I know it sounds funny, but when I put all those little parts together, I just felt a feeling of a accomplishment. K
I know it sounds funny, but when I put all those little parts together, I just felt a feeling of a accomplishment.
Me too!
..... Bob
Beam me up, Scotty, there's no intelligent life down here. (Captain Kirk)
I reject your reality and substitute my own. (Adam Savage)
Resistance is not futile--it is voltage divided by current.
Seamonster I guess we are the only one's that muck with circuits
I can't beleve how many 555 timers there are, I picked up the LM555CN and got 50 of them for $12, but at radio shack there $1.65 each and I see others at the shack for $1.89
only thing I see is the start volt from 2 to 5, I had no idea that there were so many different one's I hope I got an exceptable chip
I have been using the 555 chip for quite a few years. It is a versatile chip. Much of the time I use it for timing. As an example, I wanted to simulate a arc welding operation with a 1.5 volt micro lamp. I hooked the lamp up to a transistor radio without the speaker. With the volume and tuning, I got a nice flash rate but but much of the time it was continuous so I put a 555 in series with one lead to the lamp and set the timing for 7 seconds of flashing and 3 seconds no flashing. The lamp, coated with a little blue highlighter is under a tender at the opening of a roundhouse door. An on/off switch provides simple control.
It is a chip I love to use.
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.
thanks joe & rich
I will have to try that radio trick
I had to do it, I just ordered some NE556N 556 Timer IC chips, like 25 of them.
there like two of the 555 in one unit. I also grabed some lm334z and 2N3904 and 2N3906 Transistors. I think I will need a breadboard, this is all new to me.
I did use a mico plug from an old cd-rom to plug the 555 into and it works great.
bring on the flashing led's
KJC
I just made this circuit it is powered by a 9 volt battery, suitable for warning lights on a tall structure
its cool I will have to try and slow it down a bit its wicked fast, looks like a gyralight
I love it my second circuit
I will have to get a video sometime
looks like trains and transistors are not to popular here
oh well I will keep looking for that great circuit that will fit just right with my city layout
NOT BACK BY POPULAR DEMAND (ME)
I haven't dabbled in IC555's, but on my last HO layout, I built the walkaround throttle from "Easy-to Build Electronic Projects for Model Railroaders" by Peter Thorne. It was pretty simple and it worked real well after I swapped resistors a couple of times on it to get the right range as I remember....but that was almost 25 years ago. I enjoy building those kind of projects myself, but the real tight IC projects I'd rather buy than build. My luck has never been the greatest with getting them to work properly.
Bob Berger, C.O.O. N-ovation & Northwestern R.R. My patio layout....SEE IT HERE
There's no place like ~/ ;)
hey these books seem to be from the seventys
I think we need some new ones, I did check a quick search for Easy-to Build Electronic Projects for Model Railroaders and found a few more circuits thanks luvadj
Budliner wrote: hey these books seem to be from the seventysI think we need some new ones, I did check a quick search for Easy-to Build Electronic Projects for Model Railroaders and found a few more circuits thanks luvadj
My god Budliner! where on earth did you get that book????? I used that book extensively (I think i kept checking it out from the library for over a year) when i first started out in the hobby. I build a crossing flasher and Lynn Wescott's Twin-T train detection circuit and signal target lighting system from that book!...It's been out of print for years!...Surely do wish i could find it again. i've searched for years and have not found that book! I still have the board that has some of the electronics on it somewhere in my junk pile out back but don't remember how to reconnect everything.... by the way..the crossing flasher circuit burned up after about a year of use....(that's why i like to buy the premade circuits now-a-days) chuck
I found the article about repairing the Troller was interesting...
Try here ( 11 used & new available from $4.42) :
Budliner wrote: Seamonster I guess we are the only one's that muck with circuits I can't beleve how many 555 timers there are, I picked up the LM555CN and got 50 of them for $12, but at radio shack there $1.65 each and I see others at the shack for $1.89only thing I see is the start volt from 2 to 5, I had no idea that there were so many different one's I hope I got an exceptable chip K
Yeah, there aren't many of us electronic hobbiests (hobbyests?--whatever!) left now. Everything is pre-made, plug-and-play and throw away when it ceases to work. Electronics has been my hobby for a good 50 years now, and I earned a good living at it too, but even the technicians I worked with had no interest in it outside the workplace. I can't count the number of Heathkits I put together over the years. Remember them? I've got all the Peter Thorne books and refer to them often. He could present a project in the most easily understandable way of anybody.
Re your 555s: you got to watch out that there are two kinds--TTL compatible and CMOS. If you try to power one of the TTL types off 12 volts along with some CMOS it'll fry. Don't ask me how I know! The suffix of the part number tells you which is which, but offhand I can't recall what it is.