They are correct. Just watch out the polarities of the cap if they are electrolytic...positive towards the collectors.

Allen

 

Started putting the PCB together Friday night and finished it up late Sunday night.

My eyesight is not so great, and (if you're done laughing) I obviously need some practice with my soldering technique..... so.... confidence was not high!

Added the power supply and I had six random lights on constantly.... I was not amused.

But then I looked back at it the next morning and a bad connection jumped out at me.... then another. In the end, there were only 4 bad solders and luckily no cross connections. After I fixed those up the board worked just the same as on the bread board version.

THANK YOU ALL FOR YOUR HELP!!!!!

I still think that some of my connections are "suspect", so if there's a resin or something typically used to secure the back side of the board to avoid damage while handling I'd be thankful for that info....

Sometime in the near future I'll post a youtube on this project and can post a link here if anyone is interested.....

Wolf

 

Did you try MrChips' circuit using 74HC164? I simulated the circuit using proteus and it worked fine. See the sim attached.

But you cannot connect 6V directly to the 74HC164. You can pass the 6V through a diode (1N4001) to drop 0.6V before feeding the Vcc of the 74HC164.

Since you're also using the proteus sim, you might try it out yourself.

Allen

Hey Allen.... I do want to play with MrChips suggestion while I also reference your simulation schematic. To get the end size of the circuit as small as possible though, I want to use either a 4060 or a 3909 as a clock instead of the AMV I used previously.

Do you know which of the above would work best, and why my Proteus 8 Demo doesn't even have a 3909 in the library? (I also have some 555's, but I've been told they eat battery life up quick).

BTW.... I did post a YouTube on the previous circuit board....

https://www.youtube.com/watch?v=vLNzhIcpW8E

Thanks for any input,
Wolf

 

Hi Allen,

I recreated your sim schematic and it kinda works in Proteus.... (the led's all come on in sequence and stay lit, then they all go off in sequence.) A cool effect but not the same as what I had built previously.

When I build the exact same circuit on a bread board though, it does nothing at all....

Any ideas?

Thanks,
Wolf

I breadboarded the 74164 circuit and found that it was working fine. Instead of using the astable multi-vibrator circuit I am using a 555. If you're using 6V for Vcc it might be too high and can spoil the 74HC164 in long run. Just put a 1n4001 or 1n4148 in series with the 6V battery on the positive terminal before entering your circuit.

I'll post my breadboard when my photo is ready.

Allen

 

Ok Allen..... I haven't messed with diodes b4 and I don't know what all they do... but I'll see if I can pick some up. I have tons of resistors... can't I use a resistor instead if I simply need to drop the voltage going into the IC?

BTW.... the 74HC164 is rated at 7V max. input, so really not sure why 6V would be an issue.

Also, I have a variable power supply and tested the circuit at 5V with the same results.

Wolf

 

Can you describe the problem or show us a picture of the problem?

the 74HC164 is rated at 7V max. input, so really not sure why 6V would be an issue.

Yes, you're right. It should be able to work from 2 to 6V on Vcc. I thought that 74HC was the same as 74LS... sorry.

Allen

 

Can you describe the problem or show us a picture of the problem?



Yes, you're right. It should be able to work from 2 to 6V on Vcc. I thought that 74HC was the same as 74LS... sorry.

Allen

Hey Allen..... You're the only one here trying to help me with this different version of the same circuit I already did, so you need not apologize for anything.... I really appreciate the time you're giving me.

I'm still very new to electronics, so I try to keep things as simple and straight forward for myself, so my mind can grasp how things are physically connected. That being said, a schematic like you have posted recently is not the approach I am taking..... I don't want to try and work with 3 or 4 power connections and 7 grounds. I'm using a battery with two terminals off of it so I design the Proteus diagram along those lines. (call me silly if you like)

The schematic I came up with that I thought would emulate yours is posted below... and it's not perfect. Only 7 of the 8 LED's light and stay lit in sequence, and on count #8 those seven shut off, and then on count #9 (restart) the first LED does light back up and the 7 light bar repeats.

I've tried introducing various capacitors between the last IC pinout and the Resistor/NPN, but the behavior in the software remained the same.

At this point I thought..... "ok, I'll take 7 lights instead of 8"..... but the breadboard behavior didn't match Mr. Proteus again.....

I'm 99% sure I have my BB wired just like the schematic below, and it does behave like the software, but only for 5 or 6 repetitions.... Then the 7 LED's remain lit and the cycle seems to be locked up.

If at this point I cut power and turn it right back on, I only get one cycle..... if I wait a few seconds longer I get 2 or 3 cycles.... depending on ..... ? (cool off time?)

I really wanted to give you a good visual of my BB, so I spent the majority of my free time lately playing with "virtual BB" software I downloaded, but they were both cheesy.... and taking a pic of all those jumper wires prolly won't help you much.

In the schematic attached, the 8 resistors at the anode of the LED's are all 470. The other other 3 are (2x 10K, and a 1K) per your design. The transistor is a BC548.

BTW.... I really don't understand how you treated that reset pin on the IC with that switch..... I only have one physical switch to work with at the power supply.

I'm not really a stupid dummy Allen..... but I confess I'm damn ignorant of how these things work at the moment. I might have left out key info on why I'm having troubles and I prolly don't know it..... sorry.... I just don't "know the lingo". (yet) :b

I'm gonna be swamped with other matters for most of the week, so take your time.....

Thanx,
Wolf

 

1) When a schematic is drawn it is acceptable to have multiple icons of power and ground. In the real circuit these are not multiple power supplies. All the power connections represent a single node. All the ground connections are a second single node.

2) Do not connect capacitors directly to output signals. This is asking for trouble. You will see increased current spikes when the output driver attempts to overcome the capacitance of the load.

3) What you have not shown are power supply filter capacitors. This is very important and not optional. Put a 0.1μF capacitor between the Vcc and GND pins of the 74HC164. Put a 10μF electrolytic capacitor across the power supply lines where the battery power enters the board.

4) It is best to show a photograph of your board, not a "virutual BB". This way we can catch real mistakes, not virtual mistakes.

 

555 timers do not eat battery power quickly if you choose CMOS 555 such as TLC555 or LMC555.

 

Diodes can be used to drop voltages. Each diode will drop about .6 to .7 volts.
The voltage drop across a resistor is directly related to the current through the resistor.
Hence the diode is a better choice for reducing the 6V supply.

 

1) When a schematic is drawn it is acceptable to have multiple icons of power and ground. In the real circuit these are not multiple power supplies. All the power connections represent a single node. All the ground connections are a second single node.

Hey Chips..... thanx for returning to this thread.... I still need some help making a smaller version of the first attempt. (it will barely fit in my model if I chop some corners, but I'd rather use your earlier suggestion and make a circuit with less components and less voltage.)

Yes, I've seen plenty of schematics where there are multiple positive and negative connections, and of course IC's shown with pins completely out of place.... but at my skill level I prefer to keep things as visually realistic as possible. I think this helped me while I was soldering up my first board because by the time I flipped it over and was dealing with all that "blind soldering", I pretty much had the circuit memorized by then.

2) Do not connect capacitors directly to output signals. This is asking for trouble. You will see increased current spikes when the output driver attempts to overcome the capacitance of the load.

I've read this particular point of yours more than the rest and I still don't understand what you're describing bud... maybe you can express this lesson in other terms? I never did use a capacitor like this on my BB because it didn't seem to do a thing in the software. It's my understanding though that it should have because a capacitor is supposed to "stall" the current flow?

3) What you have not shown are power supply filter capacitors. This is very important and not optional. Put a 0.1μF capacitor between the Vcc and GND pins of the 74HC164. Put a 10μF electrolytic capacitor across the power supply lines where the battery power enters the board.

Chips, if I create a connection of any sort (with a capacitor, diode, anything in the path) between the + and - of the IC, won't that short the whole thing out?

The lowest C I have on hand are 4.7. I never used (or was it suggested) a filter C on my 9V board of this circuit and I ran that thing for 3 days straight without any problems.

I do have a variety of capacitors, but I don't know if they are electrolytic, ceramic, psychotic, or what..... they are polarized though.... :b

4) It is best to show a photograph of your board, not a "virutual BB". This way we can catch real mistakes, not virtual mistakes.

OK..... ("be careful what you ask for") :b

 

555 timers do not eat battery power quickly if you choose CMOS 555 such as TLC555 or LMC555.

I do have a few 555's, but I was playing around with a 3909 instead.... (didn't behave the same as the AMV though for clocking the other IC).

My 555's are stamped NE555P / XSD 218G

(When you're first starting out playing with electronics and go to eBay to buy a bunch of cheap stuff, hard to say what you've really got on hand) :b

 

Diodes can be used to drop voltages. Each diode will drop about .6 to .7 volts.
The voltage drop across a resistor is directly related to the current through the resistor.
Hence the diode is a better choice for reducing the 6V supply.

I think I actually understand what you're saying here Chips, but since you didn't use terms I expect, I need to ask you some Q's....

A) Is a diode just like a resistor, but used for smaller increment drops of current/voltage passing on to the next component?

B) If a diode is a better choice for dropping the voltage entering an IC, why isn't a better choice to restrict voltage to the anode of an LED?

C) If you're building a circuit and you must have a certain IC that max's out at 5V, but you also need 9V to power a must have LED strip, would you use ohm's law and use a series of diodes, or would you use a single resistor to restrict current to the IC?

D) Since I'm building a circuit with an IC that's rated at 7V max, and I'm using a 6V supply, why do I want to restrict the voltage at all?

 

I do have a few 555's, but I was playing around with a 3909 instead.... (didn't behave the same as the AMV though for clocking the other IC).

My 555's are stamped NE555P / XSD 218G

(When you're first starting out playing with electronics and go to eBay to buy a bunch of cheap stuff, hard to say what you've really got on hand) :b

The LM3909 is meant to be an LED flasher, not as a clock circuit which your circuit requires.

NE555P is a power hungry timer chip. This is not a CMOS version.

 

I think I actually understand what you're saying here Chips, but since you didn't use terms I expect, I need to ask you some Q's....

A) Is a diode just like a resistor, but used for smaller increment drops of current/voltage passing on to the next component?

No. A resistor has almost constant resistance and hence obeys Ohm's Law, I = V/R. The voltage drop across the resistor will vary with the current, V = IR.
A diode does not have a constant resistance and exhibits a very non-linear V-I behavior. In fact the V-I curve is exponential. For your application, it starts conducting at 0.6 to 0.7 volts and we can use it like a 0.6V zener regulator.

B) If a diode is a better choice for dropping the voltage entering an IC, why isn't a better choice to restrict voltage to the anode of an LED?

For an LED, we want to control the current, not the voltage. That is why we use a resistor. A perfect constant current source has infinite resistance. Hence for an LED circuit, the higher the resistance, the better it is as a constant current source presuming that we have satisfied the LED current requirements.

C) If you're building a circuit and you must have a certain IC that max's out at 5V, but you also need 9V to power a must have LED strip, would you use ohm's law and use a series of diodes, or would you use a single resistor to restrict current to the IC?

You would be best to use a constant voltage circuit such as a 3-terminal voltage regulator or a zener diode circuit.

D) Since I'm building a circuit with an IC that's rated at 7V max, and I'm using a 6V supply, why do I want to restrict the voltage at all?

I am only responding to the drawbacks of using a resistor to lower the supply voltage. Are you certain that your supply voltage does not exceed 6V? Putting a 1N4001-1N4007 series diode in series with the 6V supply followed by a 10μF electrolytic cap to ground seems like a good idea.

 

And here's the BB..... (s)

Ignore the far right clear BB which just has the AMV on it.

On the white board (to the far right), there's a 3909 IC, capacitor, etc... but I couldn't make that work..... if you have really good eyes you'll notice the power and ground jumpers and dangling in the wind.....

Just to left of that you'll see a PNP and resistor doing nothing...... something else I was playing with......

Left of that is the circuit I described (way) above where I have 7 LED's "bar light" in sequence..... for a few cycles.... etc.....

Enjoy..... :b

 

My responses in blue.

1) When a schematic is drawn it is acceptable to have multiple icons of power and ground. In the real circuit these are not multiple power supplies. All the power connections represent a single node. All the ground connections are a second single node.

Hey Chips..... thanx for returning to this thread.... I still need some help making a smaller version of the first attempt. (it will barely fit in my model if I chop some corners, but I'd rather use your earlier suggestion and make a circuit with less components and less voltage.)

Yes, I've seen plenty of schematics where there are multiple positive and negative connections, and of course IC's shown with pins completely out of place.... but at my skill level I prefer to keep things as visually realistic as possible. I think this helped me while I was soldering up my first board because by the time I flipped it over and was dealing with all that "blind soldering", I pretty much had the circuit memorized by then.

You can reduce the physical size even further by going to a single chip solution using a microcontroller and using an SMD package.

2) Do not connect capacitors directly to output signals. This is asking for trouble. You will see increased current spikes when the output driver attempts to overcome the capacitance of the load.

I've read this particular point of yours more than the rest and I still don't understand what you're describing bud... maybe you can express this lesson in other terms? I never did use a capacitor like this on my BB because it didn't seem to do a thing in the software. It's my understanding though that it should have because a capacitor is supposed to "stall" the current flow?

In this application, a capacitor is used as a low pass filter. It "stalls" the voltage in the sense that it slows down the rise and fall of the voltage. However the current is increased in order to charge and discharge the capacitor. It is not a good idea to "short" the output signal with a capacitor. If you wish to filter out high frequency spikes, use an RC low pass filter consisting of a resistor and a capacitor.

3) What you have not shown are power supply filter capacitors. This is very important and not optional. Put a 0.1μF capacitor between the Vcc and GND pins of the 74HC164. Put a 10μF electrolytic capacitor across the power supply lines where the battery power enters the board.

Chips, if I create a connection of any sort (with a capacitor, diode, anything in the path) between the + and - of the IC, won't that short the whole thing out?

A capacitor across the power supply is a short but only beyond certain frequency. The 0.1μF cap across the power supply will help reduce the high frequency noise that is put on to the supply lines every time any signal, especially the LEDs switch on and off. The 10μF capacitor is a low frequency reservoir capacitor to help maintain a constant voltage on the supply lines as the current demand fluctuates.

The lowest C I have on hand are 4.7. I never used (or was it suggested) a filter C on my 9V board of this circuit and I ran that thing for 3 days straight without any problems.

Get a whole bunch of 0.1μF ceramic capacitors. You will need these now and in the future. This is not an option.

This is mandatory reading for you:

http://forum.allaboutcircuits.com/showthread.php?t=45583

I do have a variety of capacitors, but I don't know if they are electrolytic, ceramic, psychotic, or what..... they are polarized though.... :b

If there is a +ve or -ve sign on the case of the capacitor then it is polarized (electrolytic). A hint would also be the physical shape and size of the capacitor. Learn to recognize the different styles (and materials) of capacitors. If the value of the capacitor is equal or greater than 1μF then it is most likely electrolytic. Anything lower than 1μF is most likely non-polarized.

4) It is best to show a photograph of your board, not a "virutual BB". This way we can catch real mistakes, not virtual mistakes.

OK..... ("be careful what you ask for") :b

You would be surprised with the number of "silly" mistakes we gurus can catch from a photograph.

 

"This is mandatory reading for you:

http://forum.allaboutcircuits.com/sh...ad.php?t=45583 "

Ok Chips..... I read it.... some parts twice....

With my experience level I would be lying if I said I understood it all, but I did get the jest of what was written as far as "squirrely" behavior with electricity in general, and it's not the first time. According to this author and some others I've read, dealing with electronics (or even a wall outlet) is closer to trying to tame a lightning bolt than most ppl realize?

Anyway.... I'll stop at Radio Shack and pick up some C's..... perhaps I can get my circuit to misbehave consistently at least.

In the mean time, would you entertain me with a schematic of how you would build the circuit I want?

G'day,
Wolf


http://forum.allaboutcircuits.com/showthread.php?t=45583

 

Hi again Chips,

I bought some 0.1uF capacitors and some IN4001 diodes..... I already had some 10uF capacitors.

After adding these in every configuration you suggested (and suggested by the linked thread you advised me to read) the only improvement I see in the circuit is that it now locks up after 20 or 30 cycles instead of 6 or 7. (Last I heard, Allen was only able to get some sort of sequencing in software, which I was too, but only with 7 of the 8 outputs.)

I was able to get that 3909 to work as a clock for the 74164, but the led's would blink instead of latch constantly.... actually kind of a cool effect, but not what I was looking to end up with.

Could you please post a schematic (or better yet, a working example) of how all these components I bought will produce the effect I'm after.

Thanks,
Wolf

 

I breadboarded the 74164 circuit and found that it was working fine. Instead of using the astable multi-vibrator circuit I am using a 555. If you're using 6V for Vcc it might be too high and can spoil the 74HC164 in long run. Just put a 1n4001 or 1n4148 in series with the 6V battery on the positive terminal before entering your circuit.

I'll post my breadboard when my photo is ready.

Allen

Allen..... I'm still struggling to make this 164 do anything it's advertised as being capable of.... sorry I wasted so much time with it!

Really looking forward to your BB photo....

Wolf