Please help. 555 circuit

I have built this three times and it doesn't work? Is there something wrong with the design or am I an idiot? **broken link removed** **broken link removed**
It doesn't work in the simulator im using either.
From top to bottom in the schematic for R1 (multiturn pot) I have pin 3,2 then 1. (Is it possible that they're hooked up wrong? 3006p trimmers)
Im running it on 13.8V in a car and I tried with 7.5v and 15V in the house.
I got frustrated and decided to hook it up to a 15v supply and jump R3 with a clip-on soldering heat sink. 555's smell great when you fry'em. I have about 9 more tries before I run out of parts, but for now I will seek help in the forums and stick to the simulator. The IR array is rated at 920+nm but I bought them from china and they have plenty of visible light. I have been using a volt meter, and the array isn't getting enough voltage,(.5V out of the 2nd transistor) but just in case, I am using an IR sensitive camera as well. I am in a hurry and have to go to work now, but I will have more voltages later. I don't quite remember them all. I think that pin three on the 555 the voltage was okay, but after R3 It had only .5v and the transistors weren't doing much. Could it be that my 48LED arrays are too power hungry or something? I have looked up other examples of timing circuits with the 555 for the simulator I have (Yenka) and it seems that all of them have the controlling resistor where I have R2 and not R1, and what's with the funny loop on R1? I know that to get a reading on the resistance, It's the middle pin and one of the ends, but it seems to be completely bypassed when I have it all hooked up and there is no resistance between pin 3 and 1. BUT THE LIGHT SHOULD STILL COME ON RIGHT?? It only came on once on my first model, and stayed on. Maybe the timing was too slow but the potentiometer did nothing. Like I said, the simulator examples had the variable resistor in another spot. Thanks in advance for any advice. I am fairly new to this stuff.

Parts List:

ITEM .... Label on Schematic
PC Board
8-pin socket


Controller IC NE555 (8-pin)..................IC1
.47 uF Electrolytic Capacitor.................C1
.1uF or .01uF Ceramic Capacitor............C2
500K Multiturn Potentiometer................R1
(2) 100K Resistors....................... R2 & R4
1K Resistor .......................................R3
Kynar wire
2N2222 Transistor (Q1) (IR Driver) .......Q1
2N3055 Transistor (Q2) (IR Driver) .......Q2
Misc Mounting Hardware
High Power 48 LED array for 12v
Cigarette Lighter Adapter

You should put the pot where R2 is. The 555 won't like it if the pot is set to zero. The loop is hooking pin 1 to pin 2. I don't know the spec on your LED, but they usually need something to limit the current. Maybe it is built in.
The led is not on for a long time (180 ms.)

It looks to me like you are trying to do something illegal !

No, nothing illegal... I just want an LED array to blink on and off. It's for a nightvision camera project. I removed the IR filter off of a camera lense and if I have the array "ON" then it's too intense. I thought it might have a neat effect if I make it pulse at 10Hz, or 60Hz. aiming for syncopation.

Oh OK, Try RONV's suggestions it should work. It's just a 555, not rocket science.

!DEFGHI! said:

No, nothing illegal... I just want an LED array to blink on and off. It's for a nightvision camera project. I removed the IR filter off of a camera lense and if I have the array "ON" then it's too intense. I thought it might have a neat effect if I make it pulse at 10Hz, or 60Hz. aiming for syncopation.

Click to expand...

hi,
Take care when pulsing a bright light at frequencies around 10Hz to 20Hz, in some people these frequencies can bring on epileptic fits.

EDIT:
The problem may be due to the high power LED array, many ready built lamps have inbuilt 'soft start' circuits.
You may be pulsing the lamp ON for too short a period, I would suggest that you operate the lamp directly, use a suitably current rated push button and see how quickly the lamp can be switched ON and OFF.

Lets know what you see.

It seems to come on right away when I tap the +terminal. There doesn't appear to be any extra fancy stuff on the LED arrays, just LED's and resistors. Shouldn't I have more than .5V after R3? It's the same after both transistors as well. Is this because of the pulse that I'm seeing only .5V? I just need the light to blink and I'm frustrating the hell out of myself.

Simple fault finding proceedure. Increase you time constant for the 555 (so you can check that it is operating with a MM) Then check your switching cct for the LED array. (hint) I'd have a close look at your biasing for Q1

The 555 may not turn off the Darlington arrangement you have created. Try 1k from base to 0v. And put 10k in place of the pot.

I think you have destroyed the pin 7 discharge transistor in the 555 because maybe you turned your pot to minimum and the discharge transistor tried to discharge the entire power supply.
The pot is supposed to have a resistor in series to limit the current when the pot is turned to minimum.

So I have this problem with R1.. This is a 500k multiturn potentiometer.
Pin 1 to pin 3 or 3to1 has a resistance of 500k ohms.
Pin 1 or 3 to pin 2 is the variable resistance.
In the schematic, it looks like pin 2 is doubled back to the 12v based on the way it is drawn.
I think this was my problem.
Shouldn't it be |12v to pin 1 -|- pin 2 to R2 and pin 7 on 555 -|- then pin 3 to C2?
So the opposing pin is doubled back to 12V?
Then lastly... if that IS pin 3 doubling back to 12v, why is pin 1 jumped to pin 3 shouldn't that be broken there so all flow is through the resistor?
Is it drawn wrong or am I reading it wrong? How should I situate this multiturn pot?

I think you are reading it wrong. Nothing on R1 is connected to zero volts. pin 1 and 2 are connected together and also connected to 12 volts, Pin 3 connects to IC's pin 7 and to R2.

ronv said:

You should put the pot where R2 is. The 555 won't like it if the pot is set to zero. The loop is hooking pin 1 to pin 2. I don't know the spec on your LED, but they usually need something to limit the current. Maybe it is built in.
The led is not on for a long time (180 ms.)

Click to expand...

Sounds good... but i don't know how to situate the three pins of the pot then <???> I'm learning but not very fast. . . .and everything's out of order.
I've gone in a lot of circles. I've searched for plenty of "how-to's" on google+youtube for 555 blinking LED array. Some come really close to exactly what I'm looking for and some probably DO have all of the correct answers to my questions but none are exact, none are in order, and none are in my native noob tongue. Lots of schematics show me that there are potentiometers but none are labeled pin1 pin2 pin3. It's just a picture showing me it exists. Is the middle pin always the wiper? Do some have specific polarity? Mine are 3006p multi-turn trimmers. My simulator allows me to turn normal passive linear resistors into pots by assigning a slider to control resistance but none have three pins. I have replaced R1 and R2 with pots in the simulator and added another variable resistor just downstream of r1 before C2 to find out if it does anything... It doesn't do anything. So why then would I connect pin 2 back to the 12v if that is my variance? Shouldn't that be connected to pin 7 of the 555 and R2? This is what I was aiming for by adding the third variable resistor in the simulator. Why doesn't it do anything in the simulator or in practice? I think I'm still looking at it all wrong.
I hope I'm not being a nuisance... When the answers hit me either on my own or all of you helping me or both I'm going to feel supertarded.
I don't have any clue why I'm so confused by this. It's like when I'm looking for my car keys and they're already in my hand.
When these lights start blinking the way they should, I'm going to sleep for a long time.
For now, I'm on model 5 and determined to not waste any more parts.
When the simulator says it works and then it doesn't work in my hands, I'm blaming the simulator. ITS NOT MY FAULT HA HA HA!!
I won't let go of the monkey bait.
My hand is in the hole until this thing is done.

So I think I get it now, and as I stated before, I do feel superdense.

Okay so I had it blinking really slow. About 10 seconds on 10 seconds off. Then I realized that I have 47µF capacitors instead of .47µF. So I plugged it into the simulator and sure enough, It blinks slow with 47µF. It all seemed to do fine in the simulator with .01µF ceramic in place of the 47µF electrolytic. So I swapped it, and plugged it in, and the light came on and stayed on.... I set the pot for 98k to give it about 10Hz and nothing happened. Light stayed on then eventually something happened. The light went off and stayed off.
So I'm at square one again, but I feel that I've accomplished something.
Is it possible that it is blinking too damn fast? Ill test it out in a bit.

Why not use simple arithmatic?
47uf is 4700 times larger than 0.01uf.
With 47uf the flashing is 0.05Hz so with 0.01uF the flashing will be 0.05Hz x 4700= 235Hz which is blinking "too damn fast" to see.
With the pot set to 98k instead of 500k then the flashing is increased to 235Hz x 5.1= 1199Hz which is also "too damn fast" to see.

**broken link removed**
Okay, well I'm getting completely different numbers here.
Back to school for me it is.

!DEFGHI! said:

**broken link removed**
Okay, well I'm getting completely different numbers here.
Back to school for me it is.

Click to expand...

You do remember that C is in farads, right? So .01µF is, lessee, 0.00000001F.

ericgibbs said:

hi,
Take care when pulsing a bright light at frequencies around 10Hz to 20Hz, in some people these frequencies can bring on epileptic fits.

Click to expand...

SAY, isnt that the same pulse range fire trucks use? wonder if they ever trigger anything!>?

The pulsing lights on fire trucks and ambulances triggers traffic lights to turn green for them.