Sequencer Type Counter

[NoOneYouKnow]

Well, I need help on one more thing, again. I need an idea for a circuit, similiar to and LED sequencer. It needs to light LEDs, up to 9, in order. So, 1, 2, 3, ect. However, I need to previous LEDs to stay lit as well. So, 1 led, 2 leds, 3 leds, ect. Any ideas? Thanks in advance.

 

[alphamike27]

Try a 4017 decade counter..............................

 

[ericgibbs]

Try a 4017 decade counter..............................

Hi,
He wants the LED's 1 thru 9 to stay LIT, the 4017 will not do that. the outputs are high and low in sequence.

 

[Pommie]

Check out the LM3916. It will produce a bargraph but needs an analogue voltage as its input.

Mike.

 

[Roff]

Check out the LM3916. It will produce a bargraph but needs an analogue voltage as its input.

Mike.

Shouldn't that be LM3914? LM3916 is nonlinear. It would still do what he wants, but it might look a little funky.

 

[3v0]

It might be fun to clock serial in shift register(s) with a 555. Wire the 10th bit back into the **** registers clear. Depending on the active state of the clear you may need an inverter.

EDIT: Tie the serial in pin on the shift register high. That will cause it will shift in 1's at the clocks speed. Tie the output enable active

 

[Roff]

It might be fun to clock serial in shift register(s) with a 555. Wire the 10th bit back into the **** registers clear. Depending on the active state of the clear you may need an inverter.

EDIT: Tie the serial in pin on the shift register high. That will cause it will shift in 1's at the clocks speed. Tie the output enable active

**** register? Who makes those?

 

[ericgibbs]

**** register? Who makes those?

hi Ron,
I think 3v0 is feeling a little 'flushed' with all the Xmas excitement..

 

[3v0]

If that is the worst error I make today I count my self lucky.

 

[Nigel Goodwin]

You can't beat starting the new year with a little toilet humour

 

[NoOneYouKnow]

Alright, I checked out the LM3914. It looks like it would suit my needs, to a degree. I still need a way to produce the analogue signal based on x number of pulses, with 18 being 5v. Also, the LM3914's equivalent is fairly expensive on Mouser.

I had this circuit wired perfectly using a 4017 matrix at one point, but is there any way to keep the outputs high? I'm really stumped here.

Also, I'm a bit wet behind the ears and have never heard of shift registers. Any additional information?

 

[Roff]

Is this what you want (the sequence starts at the bottom)? It was generated with two 74HC164 shift registers and a 74HC04. I can post he schematic if this is what you need.

 

[NoOneYouKnow]

That looks about right, but I need 18 in the sequence instead of just 9. Also, once they're all on, they should remain on until reset, whether it be by a high or low signal, either will work for my application.

 

[adog111]

I'm working on a project similar to GOkussj5okazu's, and would benefit with a peek at Roff's schematic - I'm a little confused on the enable A and B. Should both be tied high and use the clock input on the 74HC164 to shift the data? (I've tried that and all I get is all outputs high)

 

[ericgibbs]

I'm working on a project similar to GOkussj5okazu's, and would benefit with a peek at Roff's schematic - I'm a little confused on the enable A and B. Should both be tied high and use the clock input on the 74HC164 to shift the data? (I've tried that and all I get is all outputs high)

hi,
Perhaps this table will help.

 

[adog111]

Thanks Eric - the table you posted is slightly different than the one in a datasheet I found. This shows the MR input has to be set high in order for the data to 'shift' on a clock cycle, right? I have tied both enable inputs high, and left the MR input float. The result I get is 'high' in all the output registers. If I set the MR to low, the outputs go low, as soon as I remove the low, all registers go high again. The clock input seems to be doing nothing.

 

[shokjok]

You could use a 4017, 4040, or 74C175 with latched outputs using a 4013 D flip-flop wired as a divide-by-two unit and tying all RESET pins together. Then you will have all LEDs on until a manual reset is done. With the LM3914, you need a DAC to feed the input and probably driver transistors to handle the current draw.