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4033 7-Seg. Counter

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chixdigit

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If you've ever used a 4033 mabey you'll know the answer to this.My circuit works great except on power-up the 7-seg is supposed to go to 0 but it goes random.I've tried everything I can think of.Any suggestions world be great!
 
The CD4033 has a reset pin like all other counter ICs. If you connect a resistor and capacitor to it, then the CD4033 will be reset during power-up.
 
This is called "power on reset". A 47k resistor and a 100 nF capacitor should be adequate.

The 4033 has an active high reset, so connect the resistor between Vcc and the Reset pin and the cap between the reset pin and gnd.
 
I did the same thing in a clock I did last year using the same 4033. I've put a resistor of 100k and a capacitor of 1uF to have more time in reset mode during the power up.
It runs perfectly!
 
ljcox said:
This is called "power on reset". A 47k resistor and a 100 nF capacitor should be adequate.

The 4033 has an active high reset, so connect the resistor between Vcc and the Reset pin and the cap between the reset pin and gnd.
Len, I think you got the R and C reversed.
 
Ron H said:
ljcox said:
This is called "power on reset". A 47k resistor and a 100 nF capacitor should be adequate.

The 4033 has an active high reset, so connect the resistor between Vcc and the Reset pin and the cap between the reset pin and gnd.
Len, I think you got the R and C reversed.

Yes Ron, you're right.
 
Here's the schematic

I dunno whats going on but now it starts at 0 but it won't count. Kinda the same problem that's been going on for me from the beginning. I know its going to be something stupid that I'm over looking but I guess that's why I'm a Newbie, if you guys could figure it out I'd be much obliged!
 

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What do you expect the photo-diode to do? It is forward biased by the 1k resistor so always has about 1.5V across it. The counter has nothing to count.
 
photo

I have a the photodiode tied to Vcc through a 2.2K resistor.The circuit is for an air hockey table, when the infrared beam is broke it will incrament the clock.That part I'm not to concerned with because it works fine.
 
I agree with Audio. The diode is reversed.

What voltage do you read on the C input (pin 1) to the IC when the light is on and when it is broken?

You need it to change from roughly 0V (light on) to Vcc (light off) in order to make the counter increment.

Also, you do not have a bypass capacitor. You need a bypass of 100 nF ceramic across the Vcc & Gnd pins of the IC to prevent odd effects.
 
Working now!

Gotter going there now. I had to revese the 100n cap and the 47K resistor and lower the resister down to 1K (For anyone who may car to use this circuit at a later time)
 
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