Need LED assistance...

[williB]

this is mine..
This one Flashes as many LED's as ya want , per stage.
it requires 4 IC's per side
plus 6 FET's the usual current limiting resistors=6
hold for the values...

 

[williB]

never mind wht Q4 says ,they can all be just about any n-channel Fet...

 

[audioguru]

I was thinking about doing it this way:

 

[williB]

IC1=CD4022 Devide by 8 counter..( 2 ) required ..1 per side
IC2=LM555 timer ( 1 ) required..
IC3,4,5 are CD4013 Dual D type Flip Flops ( 6) ...3 per side..
Q1 to Q6 = any available N-Channel FET... (12) .. six Per side.

These FETs can control heaps of current easily 100 mA which means you could have some very bright turn signals. There are no values for the current limiting Resistors ( i dont know what LED's you are gonna use yet,or how many)

Current limiting resistors ( 12)
R3=10K .. (1)
R4=100k ..(1)
C1=5 micro F .. ( 1)
C=0.1micro F .. ( 1 )

**broken link removed**
oh i found this site if you plug in 10 - 100-& - 5- you get approx 1 second period on the clock(555)

 

[gerty]

Another simple one..The 10 channel led chaser, you can cut it off at 6 if you want to...
**broken link removed**

 

[audioguru]

Hi Gerty,
Your chaser circuit has only 1 LED on at a time. Maxer wants the number of lighted LEDs to increase during the sequence.

 

[williB]

latest version.. i had inadvertlanty left some connections off the555 timer..

 

[audioguru]

Hi Willi,
Sorry, but you can't use the CD4022 chaser's "carry" output to reset the flip-flops because it isn't a true carry function. It is high for counts 0 through 3, then low for 4 through 7. I recommend that you use count 7 output to reset the flip-flops.

The LM3914 has "flip-flops" built-in which are activated by simply tying its Mode pin to the bar function. Its outputs can also supply the required current without extra Mosfets. It is designed to drive LEDs in a sequence.

 

[Maxer]

I was thinking about doing it this way:

what is the purpose of 1uf capcitor? I think i would go with LM3914 one of my friend is helping me out with that as well...
he said 2 sequences can be achived with this
dot and bar with a toggle switch...
thanks
max

 

[williB]

Hi Willi,
Sorry, but you can't use the CD4022 chaser's "carry" output to reset the flip-flops because it isn't a true carry function. It is high for counts 0 through 3, then low for 4 through 7. I recommend that you use count 7 output to reset the flip-flops.

The LM3914 has "flip-flops" built-in which are activated by simply tying its Mode pin to the bar function. Its outputs can also supply the required current without extra Mosfets. It is designed to drive LEDs in a sequence.

Hi audioguru..
wheres maxer.. ??
anyway ..i was counting on reset being edge triggered. on a low to high transition ...but as you pointed out it isnt..crap..

 

[williB]

thanks for the heads up..this should work.. thanks again..
i really like this eagle software.. once ya get beyond its quirks it works great!!

 

[Maxer]

thanks for the heads up..this should work.. thanks again..
i really like this eagle software.. once ya get beyond its quirks it works great!!

Ic chips are more expensive in that modle and more complex to make, would LM3914 work the same?
here is the diagram i made my buddy told me to take out that 1uF capacitor but correct me if its wrong, he said he found this info on data sheet. i don't know how to draw schematics so excuse the shity work
but thanks for your help so far audio and willi
max

 

[williB]

i think that you could run the LM3914 with P Channel Fets ..ya probably

 

[Maxer]

i think that you could run the LM3914 with P Channel Fets ..ya probably

here is better schematic of what i want to do are the Fets necessary?

 

[williB]

i think that you could run the LM3914 with P Channel Fets ..ya probably

here is better schematic of what i want to do are the Fets necessary?

yes , if you want the brightest LED's possible..with the FETs you can drive as many LED's as ya want per stage..

 

[audioguru]

Hi Max,
The 1uf cap is important because its rising charging voltage is what is indicated by the LM3914 voltmeter. I was going to use the 7th output of the LM3914 to discharge the cap but realised that when the cap begins to discharge, the 7th output signal disappears, and the cap would never discharge to zero volts.
So I added a 555 oscillator at the last minute that would use its discharge pin #7 to discharge the 1uF cap to zero.
The transistor is configured as a constant current source, to charge the capacitor linearly with time. You could use just a simple resistor to charge the cap instead of the transistor, but then the cap would charge exponentially, starting with a very fast voltage rise then slowing down.

Your revision to my circuit shows the LM3914 indicating the voltage of the cap in the 555 oscillator. That would be awkward because the 555's cap normally operates at between 1/3 to 2/3 of the supply voltage. So the LM3914 must have its low and high voltage points also the same. When power is applied by your turn-signal switch, the cap will be at zero volts and take some time to reach the 1/3 supply voltage that would turn-on the LM3914's 1st LED. A very noticeable delay.
My 1uF cap would start charging and the LM3914 would indicate its voltage immediately when power is applied by your turn-signal switch.
But now I realise that the very 1st time period of the 555 is longer than all the rest. That would cause the 1st sequence to end with all 6 LEDs lighted and a delay before they are turned off and the next sequence begins. I'll think about how to fix that.

Hi Willi,
The only time the LM3914 needs Fets is when it is driving high-current light bulbs. It can directly feed 20mA to the LEDs with no problem.

 

[Maxer]

Hi Max,
The 1uf cap is important because its rising charging voltage is what is indicated by the LM3914 voltmeter. I was going to use the 7th output of the LM3914 to discharge the cap but realised that when the cap begins to discharge, the 7th output signal disappears, and the cap would never discharge to zero volts.
So I added a 555 oscillator at the last minute that would use its discharge pin #7 to discharge the 1uF cap to zero.
The transistor is configured as a constant current source, to charge the capacitor linearly with time. You could use just a simple resistor to charge the cap instead of the transistor, but then the cap would charge exponentially, starting with a very fast voltage rise then slowing down.

Your revision to my circuit shows the LM3914 indicating the voltage of the cap in the 555 oscillator. That would be awkward because the 555's cap normally operates at between 1/3 to 2/3 of the supply voltage. So the LM3914 must have its low and high voltage points also the same. When power is applied by your turn-signal switch, the cap will be at zero volts and take some time to reach the 1/3 supply voltage that would turn-on the LM3914's 1st LED. A very noticeable delay.
My 1uF cap would start charging and the LM3914 would indicate its voltage immediately when power is applied by your turn-signal switch.
But now I realise that the very 1st time period of the 555 is longer than all the rest. That would cause the 1st sequence to end with all 6 LEDs lighted and a delay before they are turned off and the next sequence begins. I'll think about how to fix that.

Hi Willi,
The only time the LM3914 needs Fets is when it is driving high-current light bulbs. It can directly feed 20mA to the LEDs with no problem.

wow great explanation even tho i am bit confused simply because i don't have much exrience with electronics but thanks.
is the swith possible on this IC so if i wish i could change the sequence from
O
OO
OOO
to
Oooooo
oOoooo
oooOoo
i could pick one i want and switch it occasinally.
thanks again
Max

 

[Maxer]

Hi Max,
The 1uf cap is important because its rising charging voltage is what is indicated by the LM3914 voltmeter. I was going to use the 7th output of the LM3914 to discharge the cap but realised that when the cap begins to discharge, the 7th output signal disappears, and the cap would never discharge to zero volts.
So I added a 555 oscillator at the last minute that would use its discharge pin #7 to discharge the 1uF cap to zero.
The transistor is configured as a constant current source, to charge the capacitor linearly with time. You could use just a simple resistor to charge the cap instead of the transistor, but then the cap would charge exponentially, starting with a very fast voltage rise then slowing down.

Your revision to my circuit shows the LM3914 indicating the voltage of the cap in the 555 oscillator. That would be awkward because the 555's cap normally operates at between 1/3 to 2/3 of the supply voltage. So the LM3914 must have its low and high voltage points also the same. When power is applied by your turn-signal switch, the cap will be at zero volts and take some time to reach the 1/3 supply voltage that would turn-on the LM3914's 1st LED. A very noticeable delay.
My 1uF cap would start charging and the LM3914 would indicate its voltage immediately when power is applied by your turn-signal switch.
But now I realise that the very 1st time period of the 555 is longer than all the rest. That would cause the 1st sequence to end with all 6 LEDs lighted and a delay before they are turned off and the next sequence begins. I'll think about how to fix that.

Hi Willi,
The only time the LM3914 needs Fets is when it is driving high-current light bulbs. It can directly feed 20mA to the LEDs with no problem.

wow great explanation even tho i am bit confused simply because i don't have much exrience with electronics but thanks.
is the swith possible on this IC so if i wish i could change the sequence from
O
OO
OOO
to
Oooooo
oOoooo
oooOoo
i could pick one i want and switch it occasinally.
thanks again
Max

" I realise that the very 1st time period of the 555 is longer than all the rest. That would cause the 1st sequence to end with all 6 LEDs lighted and a delay before they are turned off and the next sequence begins"
yea if that can be fixed it be perfect
here is the toggle switch schematic does it look right?
it shoudl be correct i found it on another website instructing me to to do it this way..
here is a site that might help you Audio with this
thanks
max
**broken link removed**
https://www.4qdtec.com/wfg.html
friend said this might help you with that problem where all 6 light up at the end and its slow..

 

[Maxer]

i also found this **broken link removed**
its a tutorial over this IC
its nice its hooked up to 12V with 10 LED's

 

[williB]

Hi Willi,
The only time the LM3914 needs Fets is when it is driving high-current light bulbs. It can directly feed 20mA to the LEDs with no problem.
.

i know , but i thought that Max wanted to be seen at night..

this link is a single LED with a peak foward current of 50 mA..

**broken link removed**

Scroll down to the bottom..Thats Bright..!!