Trying to make this counter work!

[Iawia]

Hi,

I am trying to use a counter in my design (NTE74HC161N). Can someone tell me how to use it?

I have a clock that is pulsing that i want to be the input to this counter. but there are so many inputs.

i have grounded all inputs ABCD to give me a start at zero, put 6 V on pin 16, GND for pin 8.
6 V for Enable P and T, and still i can't get it to count when I load zeros into the input, i get no change on the output when i clock the output once.

is there something i am doing wrong? p.s. i have loaded the .pdf of the counter that i am using.

 

[crutschow]

Need to post a schematic.

What are you doing with the Load and Clear input? You can't leave any inputs floating.

 

[Iawia]

Hi crutschow,

I am getting some outputs now after your suggestion. but it is not counting in binary sequence. it'll go from 0000 to 0001 to 1000 to 0000. i don't understand the sequence.
I have put 'master reset' and 'load' to high according to the .pdf from philips of the chip with the same number (attached).

Can you offer anymore suggestions?

 

[Reloadron]

The attached image should be how your counter is configured. That is all that is needed. Pin 1 is tied high to count, placing it at a low will reset the count. Make sure there is no noise or switch bounce on the clock input.

Ron

 

[Iawia]

What do you mean by switch bounce on the cp?

I have a breadboard with the chip set up, and I am trying to simulate the clock by placing a wire to ground then to Vcc, and to simulate the second pulse would go from ground to Vcc again. Is this wrong?

 

[Reloadron]

What do you mean by switch bounce on the cp?

I have a breadboard with the chip set up, and I am trying to simulate the clock by placing a wire to ground then to Vcc, and to simulate the second pulse would go from ground to Vcc again. Is this wrong?

Yes, that is not a good way to simulate a clock pulse. The clock in needs to be nice clean pulses. If you could see what you are doing on a scope your simulated clock pulses would be a mess of jitter and noise as you can't get a nice clean make and break. Even a push button switch would give you noise and an erratic count. Thus the term "switch bounce". Give this link a look. Or just do a Google of Switch Bounce to see exactly what I am getting at.

Something you can try is place a 10 K Ohm resistor between your clock in pin and Vcc ( a pullup) and place a .1 or .01 uF cap to ground from your clock in pin. Now tap the clock in to ground to clock the chip. Since the counter increments up on a low to high each time you break ground to the clock in the counter should count up. If your circuit is what I posted and is erratic as you describe the problem is switch bounce.

Ron

 

[Iawia]

Hey thanks Ron. I think it is counting properly now. I hooked it up to a tlc555 timer. I wont know for sure until i implement the decoder. Thanks. I really appreciate your help.

 

[Iawia]

Your link to switch bounce was also very helpful. No wonder my outputs were not sequential. It made several bounces each time.

 

[Reloadron]

Good and glad it seems to be working out. Our pleasure to help.

Ron